Planet Nottinghack

18 September 2018

Martin Raynsford hackergotchi for Martin Raynsford

New laser cutter

My new laser cutter arrived at the start of last week, I feel a little guilty for not posting it sooner especially as I've been teasing it on Twitter all week but here it is, in all it's glory in a single post.
It's a 500x300mm cutting area with a 30W metal RF tube. Everything about this machine is designed for speed and in quick initial testing I've managed to take it up to 1000mm/s and it seems to run fine without skipping steps.

The laser head is super light weight and the belts are nice and thick which helps to avoid bounce when changing direction.

Mirror 1 has a beam combiner for the red dot light, another bit of weight off the gantry.

Proper linear screws on the Z axis make for very smooth vertical motion and inductive limit switches on all axis to avoid mechanical wear.

Finally the laser itself is a 30W metal RF tube. There are a lot of websites which offer information about Glass vs Metal tubes, now I have both I can compare to see which is best.

by (Martin Raynsford) at 18 September 2018 10:26 PM

16 September 2018

Martin Raynsford hackergotchi for Martin Raynsford

Fluorescent Signs

Photo by Sophie Garrett
Saving my best for last were these signs that were mounted on the containers to indicate who was exhibiting inside them. They were engraved onto Fluorescent Acrylic so that the caught the UV lights positioned all around Cybar. My initial intention was to side light them with my own UV led strip but that didn't arrive in time so I was lucky that there was enough UV left to go round. The photographers clearly liked them too and there are some amazing shots floating round out there.

Photo by Mitch Altman

Photo by Phil Hutchinson

There were 6 signs in all, I could swear I've seen a 'puzzle hunt' image somewhere and my own 'chop shop' sign which didn't fluoresce quite as much as the others due to it being blue.

by (Martin Raynsford) at 16 September 2018 05:24 PM

15 September 2018

Martin Raynsford hackergotchi for Martin Raynsford

Central reservation barriers

Last on my list of big props for EMF Camp are these pair of central reservation barriers they're quite common in cyberpunk street depictions so I thought it would be cool. More Sheets of MDF were cut down to the right sizes, a jig saw was used to cut out the end angles. The sides were reinforced with pallet wood to give it strength, in case people decided to sit on them. The Polybius logo was embossed on each side using a router with a 45 degree bit. The paint effects were achieved by applying successive layers of grey paints with a paint scraper rather than a paint brush. The darker colour around the base was spread using a rag and wiped down to blend with the greys. Obviously the orange Polybius was added using spray paint and a laser cut stencil.

by (Martin Raynsford) at 15 September 2018 06:40 PM

14 September 2018

Martin Raynsford hackergotchi for Martin Raynsford

Making a spectacle of EMF

In the many glass cabinets at Cyberdog were lots of laser cut acrylic bangles and spectacles. I thought it would be cool to make some of these things up at camp but in the end I spent the whole time cutting badge cases (literally 12 hours a day). I did make this one prototype though which somebody loved enough to take home again. The arms were bent using a hot air gun, although I have done 'off focus' laser bending before it's definitely quicker doing it this way.

by (Martin Raynsford) at 14 September 2018 01:40 PM

13 September 2018

Martin Raynsford hackergotchi for Martin Raynsford

Faux Aircon units

Given that the Null Sector comprised of 10x 20ft shipping containers, there was a fair bit of scope for making some larger props to go in the area. A quick flick through google images shows various scenes of neon lighting and roofscapes adorned with pipework and units. I had the idea to make some faux aircon boxes to mount around the camp. As you can see some of these units crept into the back of shots and proved to be quite useful to cover up the name plates on the sides of the containers. 

Image by Sophie Garrett

The basic box shapes were made from 6mm MDF straight from B&Q, I spent a good 20 mins their annoying everybody else who wanted sheets cutting down to size but it's generally easier to pay a bit more money per sheet and have someone else cut it down into chunks that A) Can be assembled immediately and B) fit in your car. Some additional holes were cut on the laser cutter, it's a bit sticky as materials go but if you need a tri pronged hole quickly the laser cutter is a great way to go.

Fans and slats were made using the laser cutter and more traditional laser materials (the fan blades were obviously cut from the fan holes. Each blade was mounted to a central hub which set it at an angle but also housed a bearing, because of this each fan was able to spin freely in the casing once it picked up the wind. I definitely saw a few people who noticed this detail at the weekend.

All the units were painted grey with some cheap masonry paint. The fans and slats were given a second coat of shiny silver paint which was applied with deliberate streaking. The units really came alive though with the application of some rust effects. It was such a simple technique that really added character to the units and made them all very unique.

by (Martin Raynsford) at 13 September 2018 07:23 PM

12 September 2018

Martin Raynsford hackergotchi for Martin Raynsford

Rust in Pieces

With my recent builds for EMF camp I had an opportunity to try some new weathering techniques. My skills are a bit lacking and there is lots of conflicting advice/techniques online and my time was short so I went straight to Eldritch and Simon gave me some definitive answers on the subject of rust. I thought I'd write the info down here so that it can hopefully benefit someone else.

You will need.
  • White vinegar and salt, available from any supermarket and you probably already have them
  • Hydrogen Peroxide, available online or I got mine from the Boots chemist. They were unsure they even stocked it so it may pay to be a bit persistent and ask them to actually check the drawers. You'll be asked why you want it but when you have a legitimate reason like this the conversations are always fun.
  • Iron Powder, this is pre rust and not the same as Iron Oxide Powder (post rust). I bought 500g on ebay and now have about 450g left over. 
  • Super glue, I opted for a large bottle of high viscosity glue so build up the ridge effects. Always handy to have excess glue spare for other projects. 

Mix the vinegar and hydrogen peroxide together, I used a 50:50 mix and add a sprinkle of salt into the liquid. I decanted the mix into a spray bottle and filled a second spray bottle with water, this will be used for the super glue.

  • Apply a healthy does of super glue to the area you want to be rusty.
  • Spritz the super glue with water, this will cause it to dry with a texture effect.
  • When the glue is dry, sprinkle the area with some Iron Powder, it helps if the area is flat. When working at an angle I found that spray the glue with some acrylic lacquer helped the iron powder stay in place.
  • Finally spritz the iron powder with the chemical mix, this will start the rusting process. Once the area was sufficiently tarnished I sprayed the whole thing again with another coat of lacquer.

That was how I did my rust effects on the Aircon units and the Semiotic signs. I'm sure things could be done better and with a bit more experimenting it could be much more rust like but I was happy to find a quick process that covered large areas and looked great.

by (Martin Raynsford) at 12 September 2018 05:24 PM

11 September 2018

Martin Raynsford hackergotchi for Martin Raynsford

Glass cabinets of Fun

I wanted my container to look like a workshop/shop and sleeping area. I visited Cyberdog in Camden market and was quite taken with their rows of glass cabinets containing items for sale. Following on from David's assertion that Ikea is the only store that survives into the cyberfuture I acquired myself some second hand Detolf cabinets.

It turns out that flat packing and repacking cabinets is a bit of a pain and trying to transport 8 large glass panels in the back of a Luton van is a bit nerve wracking. The cabinets were packaged well with card and tied up to the railings to stop them falling over. They fit really well with the aesthetic and they served impeccably to display my kits for sale.

With my newly installed cabinets came the need to create display stands, having a laser nearby solves those issues though. I built a quick stand to hold all 4 different fractal puzzles vertically within a cube and I built some small price tags (always a good indication that stuff is for sale). One minor annoyance is that I lost all the screws on the way home but thankfully the amazing Ikea is sending me more fixings, once they arrive I'll be able to sell the cabinets onwards and break even on the whole cabinet adventure.

by (Martin Raynsford) at 11 September 2018 08:26 PM

10 September 2018

Martin Raynsford hackergotchi for Martin Raynsford

EMF Camp Badge Release

It's finally here, the files and the back panel for the EMF Camp badge 2018. That officially took too long to sort out after EMF but I used all my plastic up at the camp and it took me several days to reconnect my laser this year. So, now the excuses are out of the way, I have completed a back panel and stand offs to go between the two. This panel holds the battery down securely and protects the antennae. (svg here)(dxf here)  I'll also put it on thingiverse

by (Martin Raynsford) at 10 September 2018 07:19 PM

09 September 2018

Martin Raynsford hackergotchi for Martin Raynsford

Semiotic Standard Signs

Once the semiotic standard was established and a few legends were scattered around the Cybar camp, it obviously made sense to put a few signs up on the containers. These were cut from Polypropylene and painted badly by hand (because it was faster than airbrushing). They only started to look like real signs once I had applied some rust effects and other weathering techniques. I'm particularly pleased of the rust and there will be more of that to come.

Signs were scattered all around camp and after pointing them out to a few people they seemed to blend in too well, people kind of assumed they were part of the containers anyway, which I guess is a good thing.

My favourite has to be the shots of the DJ booths in which you can clearly see the 'laser' sign on the doors just behind the DJ's. particularly apt given that they had nearly 100W of visible laser light amongst all of their machines. This photo was taken by Sophie Garrett and she has lots of awesome EMF photos over in her Flickr Album 

Photo taken by Sophie Garrett

by (Martin Raynsford) at 09 September 2018 05:29 PM

Semiotic Standard Poster

During the build up to EMF Camp I was sent a hand drawing of the Semiotic Standard, a series of icons used in the Alien movies. I thought these were wonderful and I just had to draw them out in vector format so that we could do something with them. Of course if I had spent less time drawing and more time looking I would have found loads of people who had already done the same thing but at least I had fun. 

Once I had recreated the whole thing digitally I had some glossy posters made for me by Braunston Print (5 stars for quality and service). These posters were put up in strategic places around the container village to add to the overall set dressing.

I almost forgot to share the file in case anyone else wants to use it (svg here)

by (Martin Raynsford) at 09 September 2018 08:35 AM

07 September 2018

Martin Raynsford hackergotchi for Martin Raynsford

Filling the cybar camp

In keeping with flavour props for the cyberpunk area, I made a handful of small items that could be quickly and easily scattered around the camp to make it feel more futuristic.

First I made half a dozen CCTV cameras, the regular participants of EMF camp are potentially wary of CCTV so these had to look plausible but fake. A simple perspex hemisphere over some basic camera shapes would suffice. The cameras were then 'destroyed' so they definitely look non functional.

Simple 'microwave' dishes were made on the vacuum former which allowed me to construct a whole network of mini antennae. Magnets on the back of these items which allowed them to be placed upon the sides of the containers quickly and easily.

by (Martin Raynsford) at 07 September 2018 07:40 PM

06 September 2018

Martin Raynsford hackergotchi for Martin Raynsford

Filling the pinboard

I had to fill the pinboard with details and I stumbled upon this amazing artwork by Vasily Khazykov, I borrowed a few of his print outs to go on the wall but I also wanted something a bit more physical to go alongside it. I chose a few items from the drawings that I could turn into physical props with a fast turnaround and I spent a day last week putting some parts together. As props they look a little bit wooden and I should really spend more time on finishing. As quick decoration pieces I think they definitely added flavour to the board.

I also made a spinning hard drive gadget which I totally forgot to take pictures of, you can just about make it out on the bottom of the board here.

by (Martin Raynsford) at 06 September 2018 07:11 PM

05 September 2018

Martin Raynsford hackergotchi for Martin Raynsford

Tool wall and pinboard

In my workshop container for the weekend, I was keen to add some set dressing to the walls so the idea of a pinboard for projects and a tool wall were born. The pinboard is a simple framework outlined using some left over pallet wood which is why it has the nice scoop shapes. Laser cut brackets around the corners keep things vaguely square. The tool board was 12mm ply sheet I've had around for ages, I wanted to give it a nice graffiti style paint job so I put my airbrush to use in a variety of colours. It's the first time I've used my airbrush seriously and I think it came out ok.

The lettering on the tool wall was achieved with a lot of masking and painting of layers over several days, it was definitely a fun project and I really enjoyed trying lots of different style and techniques on a large blank canvas.

by (Martin Raynsford) at 05 September 2018 07:38 PM

04 September 2018

Martin Raynsford hackergotchi for Martin Raynsford

EMF Camp prop making

picture by @JamesHarrison

This years EMF Camp had a large cyberpunk themed area featuring art installations, a bar, DJ and lots of other interesting things. It takes a lot to set this kind of thing up in a field though for a weekend, and the team pulled out all the stops to produce an epic experience. The 'Cybar' or 'Null Sector' really came alive at night time though when all the lights came on and the lasers and flamethrowers came out.

The base encampment was laid out using twelve shipping containers, the whole campsite was circled with security fencing with tarps making it hard to see inside the camp. Truss and scaffolding was placed along the edges of many containers and between containers allowing power and lighting to be run overhead and down into each container. A large metal dome was built in the open area and a 10ft container was stacked on top of another 10ft container to provide an elevated DJ booth. Once the basic structures were in place the whole area still needed decorating according to theme. I made a selection of props to go in the area which I'll detail over the next few days.

After some initial discussion about me running my laser cutter from the back of a Luton van the team was actually kind enough to let me set up a workshop in one of the 10ft containers. I'm a bit of a sucker for a theme and decided to go all out with my setup. For the basic 'workshop' aspect of the container I just took my laser cutter and some work benches but for the shop aspect I decided I really needed to get some Detolf glass cabinets from Ikea. A quick ebay find later and I managed to get hold of a pair of the worst possible furniture items to take to a field. 

I built a few other items to go inside the container, took my wooden crates and bar top, I also strung 1200 neopixel lights across the roof to give the whole place a nice glow. I'm pleased with how well my space turned out and the the whole area was a fantastic thing to be part of. The flamethrower on the roof of my container did a good job of keeping it warm. Because I was cutting badge cases I was pretty popular all day and all night so I was glad I made the extra effort to fall in with the theme.

by (Martin Raynsford) at 04 September 2018 09:53 PM

03 September 2018

Martin Raynsford hackergotchi for Martin Raynsford

EMF Camp 2018 badge cover

I just got back from EMF camp and I spent most of my weekend cutting badge covers for people. Sadly I forgot to take photos for myself and I've had to steal others from twitter.
Marneus chose the vibrant orange and riley had a yellow case, I also cut in Red, Green and Blue. I'll post some pictures once I've recut on of each at home.

If you failed to get a badge cover at EMF camp you can now pick one up from my store.
I will also be sharing the files too but I want to cut and test something and that means emptying my Van back into my garage before I can start again.

Dominic took the files and modified them to cut his own leather version on his laser

by (Martin Raynsford) at 03 September 2018 08:42 PM

28 August 2018

Iain Sharp

VCV Rack for EMF Camp 2018

I am running a beginners workshop on the VCV Rack moduler synthesizer simulator at EMF Camp 2018. Currently scheduled for 11.20 am on Sunday in Workshop 1. If you are at EMF Camp and want to join please bring a laptop and headphones.

Here are some resources for the event:


by Iain at 28 August 2018 06:42 AM

27 August 2018

Martin Raynsford hackergotchi for Martin Raynsford

EMF Camp 2018 badge hacks

EMF Camp 2018 just released details about the badge for this years camp and it looks incredible as always (Hackaday has a great summary). It's a full blown smart phone which can be used on site using the local network or on a standard gsm network after the event. Like a lot of camp badges though, despite amazing innovations it's still just a bare circuit board dangling round your neck ready to short out against objects (like the metal of the laser cutter) so there is a bit of a need for a case to protect it.

I'm one step ahead of the curve this year and hopefully I've produced the first badge hack of 2018. I initially cut a nice wooden case to show off the fine details that a laser cutter can produce and then I cut one in florescent plastic to glow under the UV lights of Null Sector. Finally I realised I could patch into the 3.3V that is one the board itself to produce a fancy edge lit case (hard to take a good photo of it though).

If anyone is interested in getting a case for their own EMF Camp badge I'll have my laser cutter set up and running in Null Sector and I'll have a stock of surface mount LED's so if you can handle the micro soldering you can make yours glow too (I'll have a fine tipped soldering iron and all my other tools there too)

by (Martin Raynsford) at 27 August 2018 08:20 PM

26 August 2018

Martin Raynsford hackergotchi for Martin Raynsford

Scaling up to kit quantities

But firstly a divergence into glue.
I have a few kits available in my shop and some of them require glue for assembly. It's always been a bit of a sticky subject for me. I recommend Evo-Stik weatherproof wood adhesive because it grabs quickly and dries solid/clear but I've seen people try to assemble kits with school PVA, superglue or even hot glue (which never works). With this in mind I try to design kits that don't require glue at all, the useless machine went from a glue heavy box to a completely glue free box (and it only took 4 years apparently).

This new kit has one awkward part that must be glued and because it connects the drive shaft to the motor it needs to be glued properly. It's four layers of material and is the kind of part that should be manufactured a different way but time is not on my side. Instead of building each one individually I realised I could build several at once to speed things up. By leaving a row of them held together on a sprue I can glue a whole row at the same time, the sprue even helps with aligning the layers accurately. Once the glue has dried I can just snap off one at a time and insert them into the kits.

This allows me to ship another 'glue free' kit without driving myself mad with assembly, which is nice.

by (Martin Raynsford) at 26 August 2018 07:24 AM

25 August 2018

Martin Raynsford hackergotchi for Martin Raynsford

New Kit available soon

Feels like a long time since I put together a new kit but I'm pleased to announce this little WiFi controlled strandbeest is going to be available at EMF camp this coming weekend and shortly after it'll be available online. It's a mash up of the plastic strandbeest kits and my recent ESP8266 experiments so it can be driven from any mobile device.

by (Martin Raynsford) at 25 August 2018 01:54 PM

23 August 2018

Martin Raynsford hackergotchi for Martin Raynsford

Something completely different

I had a spare day and an opportunity to go on a royal icing course so I thought it would be fun to try, plus another thing to learn about that compliments the rest of my cake stuff. I learnt loads of interesting things about types of icing sugar and technique for piping icing, the brush effect on the flower is particularly effective.

by (Martin Raynsford) at 23 August 2018 08:30 PM

20 August 2018

Martin Raynsford hackergotchi for Martin Raynsford

Wooden Bar Top

The bar itself for Vale also had to be portable to get it out into the middle of the quarry. This poses a bit of a challenge because it's a large item. The wooden crates I made are so sturdy that they could be sat on so they were an appropriate place to start. The top itself is just several pallet planks sanded and connected together with a few batons. The surface then bolts into the crates with 6mm screws and wingnuts to make it fast. The whole thing goes together quickly and it all still fits on the trolley. It's a little bit low but it's functional.
I've been asking for pictures of the bar in situ but it doesn't appear anyone got one which is a shame. The whole 'setting up a bar in the middle of a warzone' thing got a bit serious almost immediately after we arrived (we were hoping for a little bit of time before anyone noticed us). It was good fun though, would definitely do it again.

by (Martin Raynsford) at 20 August 2018 09:37 PM

18 August 2018

Martin Raynsford hackergotchi for Martin Raynsford

Bar Sign

I really wish I had more photos of this. I made a sign for a bar that we ran at Vale, we set up a bar right in the middle of the quarry (hence the crates for moving beer). All good pubs need a sign and ours was no exception. The lettering and outline were coloured using paints, the areas were masked before cutting to allow a neat paint job.

The picture itself was transferred to the wood from a colour printout. There are lots of online tutorial that suggest all sorts of glue to use. The gist is that you print out onto a sheet, cover the whole thing in glue and stick it ink side down onto the wood. Once it has dried, you then wet the paper and slowly rub it off of the ink. The trouble is there is a very fine balance between not rubbing enough paper off and rubbing the ink off. In this case the blemishes work well with the style.

by (Martin Raynsford) at 18 August 2018 08:33 AM

16 August 2018

Martin Raynsford hackergotchi for Martin Raynsford

Wooden Crates

I have a lot of green plastic crates but I wanted something a little more rustic for events. I re purposed some pallets I acquired from the local industrial estate and turned them into these simple boxes. I put some small feet on the bottom that allow them to stack inside each other and they don't immediately slip off the trolley when you move them around. Not laser cut but I do rather enjoy my new mitre saw and it makes chopping planks so much easier.


by (Martin Raynsford) at 16 August 2018 10:05 PM

14 August 2018

Martin Raynsford hackergotchi for Martin Raynsford

New Vale Machine Panels

The culmination of knobs, dials, bubble rods and seals were these two new panels to go into the machine at vale.The first panel has all the input devices, when each lever is flipped or slider moved then all the LED's built into the board change colour, the rods change flash rates and the dials also move. Nothing specific just general interaction to indicate that something has changed. The second board is very much like my Stranger Things messaging systems. The board has 50 leds built into it and they have been shuffled to display letters at random (even I don't know which LED is which letter). You can connect to the board via wifi and use it to send messages back from the machine to the players. It was used last event but I wasn't there to see if it was successful, I hope it went ok.

by (Martin Raynsford) at 14 August 2018 06:22 PM

12 August 2018

Martin Raynsford hackergotchi for Martin Raynsford

Knobs, Dials and Switches

I made a collection of dial and switches for Vale at the start of the year. I've done similar things before but this time they're all functional. The plan was to put them all onto a board and allow people to actually interact with the infernal machine this year.

by (Martin Raynsford) at 12 August 2018 09:29 PM

11 August 2018

Martin Raynsford hackergotchi for Martin Raynsford

Bubble Rods

I've had these 15mm bubble rods from Kitronik for quite a long time, I thought they would look good when side lit. I used a single neopixel on each end of the rod and illuminated both ends with the same colour. The colours slowly fade on/off and at different frequencies. 22mm copper pipe fittings make perfect end caps and the the laser cut adaptors to go between the two.

by (Martin Raynsford) at 11 August 2018 07:31 PM

10 August 2018

Martin Raynsford hackergotchi for Martin Raynsford

Demonic Seals

These demonic seals were cut in ye olde MDF for that genuinely realistic appeal. The disks were painted with metallic acrylic before engraving so it was easy to wipe the dust off. These seals were going to be used as decoration on the vale machine (and were made way back in May)

by (Martin Raynsford) at 10 August 2018 06:47 PM

Wolf Coaster

Just a sample for a coaster, I masked the acrylic with vinyl transfer tape before engraving to ensure that I got a good clean cut. I didn't realise it was a coaster otherwise I would have rounded the edges and engraved it on the reverse so that the engraving was on the underside and less prone to damage during use.

by (Martin Raynsford) at 10 August 2018 09:39 AM

09 August 2018

Martin Raynsford hackergotchi for Martin Raynsford

Voting Chits

This chits were made for the LRP Game, Age of Aether. I believe the top disk is copper, silver or gold and the larger bottom disk is red, green or blue to denote different groups and weightings. I would normally paint a sheet before cutting but because the exact combinations required were unknown I left them all blank.

by (Martin Raynsford) at 09 August 2018 07:25 PM

13 July 2018

Martin Raynsford hackergotchi for Martin Raynsford

Node timer counters

In one aspect of Vale I'm making tech to keep the node system functional, from the player side of things I'm trying to find ways to hit as many nodes as possible and collect all the stuff. While you're waiting at a node it would be really useful to know how long it had been since the node last spawned. There is a 6 hour window for 3 spawns so it's going to be roughly every 2 hours. I thought it would be handy to drop these counters near the node so anyone can update the time then, if you arrive 10 minutes after the previous drop it's worth going on to the next node.

They're based on this wound counter design but two concentric rings allows me to set the hour and the minutes separately.

by (Martin Raynsford) at 13 July 2018 09:13 PM

09 July 2018

Martin Raynsford hackergotchi for Martin Raynsford

Kickstarter Fulfilment and best ever Birch Ply

I'm deep into fulfilment for my kickstarter puzzles. Roughly 600 puzzles to make in total and I'm turning over about 50 a day which is pretty good progress. Obviously it's leaving me a little bit of time to blog this month which is why I'm catching up on posts. 

The high quality BR grade plywood from Kitronik is really worth the extra money. 1 in 10 sheets has the tiniest of knots but because each ply is only 0.5mm thick it still cuts through cleanly. All the inner layers are equally high standard. If your working on a project that needs better materials this is the stuff to go for.

by (Martin Raynsford) at 09 July 2018 07:11 PM

07 July 2018

Martin Raynsford hackergotchi for Martin Raynsford

Truck Mudguards

The fathers day lorry is very similar to most of the cars we've already done but to really make it feel like a proper truck is needed some mud guards over the wheels. It would be hard to laser cut something directly to go over them but thanks to the vacuum former I can laser cut some moulds and make some plastic arches to go over them instead. Now the arches can be covered with sugar paste to match the rest of the cake.

by (Martin Raynsford) at 07 July 2018 07:58 PM

06 July 2018

Martin Raynsford hackergotchi for Martin Raynsford

Roman Horseman Shield

This item wasn't actually designed or drawn by me, I did help out though. Eli was tasked with designing a Roman shield based on his trip to the Lunt Roman Fort. He chose to make a horseman shield which is rounded to protect the horses legs. He drew the whole thing in inkscape, picked the colours and we took it to the laser. The wings were actually drawn 7 years ago so it was nice just to be able to drag the files out of my archives and use them again. The shield boss was made from vacuum formed plastic.

by (Martin Raynsford) at 06 July 2018 06:02 PM

05 July 2018

Martin Raynsford hackergotchi for Martin Raynsford

Confirmation Cake Topper

A quick laser cut from way back in May, this cake topper was to celebrate Daniels Confirmation (obviously). The spikes are a little bit fragile and spiky but it only has to go into the cake once right.

by (Martin Raynsford) at 05 July 2018 08:05 PM

19 June 2018

Martin Raynsford hackergotchi for Martin Raynsford

Fathers Day Cake Lorry

Way back in February, Dawn had the idea of making a cake based lorry in the same style as the Cake cars we're been doing. It was a great idea but I knew to shift all of the additional weight of a trailer we were going to need four driving wheels and motors. The majority of the weight would be spread over the rear of the trailer so those wheels and axles were put in place with bearings to reduce the rolling resistance. The pivot point was again made with a bearing to ease turning friction. Other minor changes included a reversing beeper and a second set of brake lights on the trailer itself (with curly cable between cab and trailer). The whole thing worked well for this quick demonstration.

The problems came when I loaded the trailer down with any weight. I ran my tests using 10kg of weight which the cab was able to pull but the steering was totally ineffective. All the weight was pushed into the drive wheels making the steering light, the sheer power of the four motors just ploughed the cab on in a straight line. At this point I was lucky with some previous design decisions. Using different motors for left and right wheels allowed me to implement a software differential between the wheels. By making the left turn faster than the right, the whole cab will steer right regardless of what the steering is doing. A little bit of tweaking got the two to line up so that the whole thing turns the right amount based on the user input.

This major problem with the lorry has been back propagated through the cars. It was only a minor issue on the cars but now it's completely gone and the cars drive much better because of it.

Dawn eventually turned the lorry into a Carlsberg van capable of dispensing beer (from a 5kg keg) hidden in the back and it's probably the best fathers day cake in the world.

by (Martin Raynsford) at 19 June 2018 07:16 PM

18 June 2018

Martin Raynsford hackergotchi for Martin Raynsford

The right tools for the job

My Kickstarter puzzles all need to be dyed and oiled before I can put the final assembly together. Obviously they can't be stacked up while they're drying so making a drying rack to store all the sheets without touching each other seemed to be a sensible idea. The whole thing was coated with some spray lacquer to stop the burnt edges of the rack marking the sheets. The whole thing works just as intended.

Another tool for the job was made without going anywhere near the laser and it's as simple as a stack of wood. A dozen planks of ply were cut to each hold a single puzzle and it's pieces. The front panel of the puzzle gets glued to the back panel and the whole thing is put on the bottom of the stack. The weight of the boards, stiffness of 12mm ply plus some extra weights from my screw boxes hold all the puzzles perfectly flat while the glue dries. When the puzzle comes out of the top of the stack it's ready for it's paper coating and it can then go in the pile of completed puzzles. Simple but effective.

by (Martin Raynsford) at 18 June 2018 08:46 PM

12 June 2018

Martin Raynsford hackergotchi for Martin Raynsford

From Shadows LRP Currency

From Shadows LRP ran it's first event at the weekend and by all accounts everybody appears to have had a good time (I was really quite keen to attend but sadly couldn't, true story). I did manage to get all of their currency cut in time though. I had previously made a few sample to demonstrate what was possible and I made a few tweaks on the final set. The colours now run in rainbow order which makes them a bit more cohesive and it allows me to keep the blue fluorescent for a higher value. I also rounded off the corners a lot more, the previous ones were a bit sharp. The tessellating design allowed me to cut whole sheets at a time with minimal wastage and even though there were a few alignment issues with the number engraved on the reverse it was still visible through the window so just about acceptable.

by (Martin Raynsford) at 12 June 2018 08:31 PM

09 June 2018

Martin Raynsford hackergotchi for Martin Raynsford

New Vale Nodes

The previous displays I made for Vale were pretty straight forward, an arduino nano was connected to a DS3231 real time clock chip and at the appropriate time they displayed a number on an LED matrix display. The whole thing was powered from the mains with a 5V PSU. This year they wanted the same thing, but on the nodes, out in the quarry and this mean battery powered and waterproofed, there had to be some fairly significant changes to the system.

Firstly, if you want a battery powered item to last for a whole weekend, LED's are a bit of a no go. They're quite power hungry and illuminating a whole display of them is going to eat through batteries. The other problem with LED's is that they can be hard to read in the sunlight and blinding in the darkness. ePaper displays however can be read in direct sunlight, can be illuminated with a torch and many only consume electricity to change the image. They seem ideal for an application like this. I opted for these waveshare 2.9 Inch epaper modules, no particular reason but they fell into a price bracket and are large enough to display a decent number.

The next design choice was to use the arduino pro mini instead of the nano. The nano has a built in USB->Serial device this chip is always on and always consuming power, the Pro mini uses a separate device to program the controller so it takes less power. The pro mini has several options too, I needed the ATmega328P for the extra RAM and memory but epaper display runs on 3.3V and the 3.3V pro runs at a slower clock speed uses less power than the 5V version so that seemed a sensible choice.

The DS3231 RTC has it's own battery back up and is designed to run at extremely low power for years. The prototype used the same clock from the previous display and it's still accurate after a year. The controller only needs to change the 12 times in a whole day so it'll also be in low power mode most of the time. The ATMega is able to wake itself up from a deep sleep using it's own internal timer but that has a maximum delay of 8 seconds, longer periods of sleep are often achieved by adding those together but there is a better way. 

The DS3231 has an alarm mode, you can program with a specific date and time and when the clock gets to that time it will change the state of one of it's output pins. This signal line can be connected to the interrupt line on the ATMega and used to wake the arduino up. This means the controller will only be awake once every two hours to change the display and then it can go back into deep sleep again. Finally, both the pro board and the RTC chip have power LED's on them, by physically removing the LED's on each of them the whole system should be reduced to a very minimal power consumption.

There are many incredibly useful discussions online about the different things you can do to reduce the power consumption of these board. A deep sleep mode with an LED consumes around 3mA, without the LED that's down to 30uA so 100 times less power. After some simple testing and current measurements, my estimates suggest that, given a screen change every 2 hours, the 3x AAA batteries in each node should now last for around 1000 hours, more than enough to cover the 60 hours they're required to run over the course of a weekend.

As for making them waterproof, well I would say they're water resistant. I would go hosing them down with a pressure washer but when they're mounted under a lip of a box or on the trunk of a tree they should be fine. There is a window of 3mm acrylic in the front of the box, this is sandwiched in 3 layers of birch ply and glued in place the overlaps should stop any ingress there. The box has standard finger joints held with liberal amounts of glue, not ideal, but inside the box these seams were closed with lots of hot glue any leaks directly through the fingers should be stopped by that. The back of the box, where the battery access is, was held on with 4 screws. It's finger joints again but there is a 3mm plate with protrudes into the box which means the inner isn't directly exposed to the joint. This should be ok when the boxes are mounted on that surface.

Next time I'll give a breakdown of the code used to drive the boxes. I had to make a few interesting choices there to make it all fit into the space available.

by (Martin Raynsford) at 09 June 2018 08:49 PM

06 June 2018

Martin Raynsford hackergotchi for Martin Raynsford

Vale LARP and Nodes

I ramble about Vale on the blog quite a lot, it's kind of hard to explain LARP to someone it's much more about being there than talking about it. I've talked about nodes and games and so on but here is the crux of the whole thing. Vale LRP is played in the vast 170 Acre site of Huntely Wood, it's a former quarry so it has woods, lakes and some serious slopes. There are two camps for two different sides of a war, the shortest route between the two camps is 1km, the long path between the camps is 2km and you can extend that exponentially if you go down all the side paths.

Out in the Vale are a bunch of different 'nodes'. These strong boxes contain game items that can be collected at various points throughout the day. This is intended to encourage groups from both sides to wander around the site and potentially bump into each other and ultimately fight over the prizes. Each section of the node is locked with a combination padlock and can only be unlocked with the right code.

Last year I made some devices that release the padlock number at a specific time, these could be loaded with a whole weekend of numbers and alleviated all the manual effort of giving out numbers at the right times. This year the number system was changed to put different numbers on each node and also to give out the numbers at the nodes. This means people have to wait out in the Vale for the numbers to appear rather than waiting in camp and trying to run to the node fastest.

The next post is going to be about the new number displays and the complications that went along with them.

If anybody would like to come along to an event then I would be happy to help set that up. New players get a very reasonable rate and I can easily put together some costume bits for you.

by (Martin Raynsford) at 06 June 2018 07:00 PM

05 June 2018

Martin Raynsford hackergotchi for Martin Raynsford

Potion Bottle Chest

I quite like to be challenged with commissions and this one certainly did that. I was asked to make a black briefcase to hold potion bottles. It also needed some space underneath it to hold cable ties and cards and other things that might need to be attached to the bottles. The whole briefcase had to be black (although I think the brown edges add to the appearance). A red cobra logo was requested for the lid, the red wood was inlaid through the lid so that the logo showed through the lid and could be seen from both sides.

The suitcase could hold 50 potion bottles and the lid closed down tight enough to stop the bottles from rattling around. The handle was built into the racking system for the bottles to ensure that it was strong enough to pick the whole case up. The hinges were laser cut which required me to add some small feet onto the bottom of the case to allow it to stand on end.

by (Martin Raynsford) at 05 June 2018 08:39 PM

01 June 2018

Martin Raynsford hackergotchi for Martin Raynsford

Hospital Runes

Another year on and I got to make the rune tags for the LRP Hospital again. I like to bring a little variation to the design so this year I gave it some shape as well as the year number.

by (Martin Raynsford) at 01 June 2018 09:49 PM

31 May 2018

Martin Raynsford hackergotchi for Martin Raynsford

Quick Stencils

I believe these stencils were used to airbrush the logo on cub scout blankets. Given that there are lots of cubs and these stencils wouldn't be needed for more than a weekend it made sense to knock up a dozen from thin card instead of mylar.

by (Martin Raynsford) at 31 May 2018 10:59 PM

Large Tape Dispenser

At the time of writing my Kickstarter campaign has nearly 200 backers which means I need to make about 500 puzzles in June. With those kinds of orders it's worth making some jigs to help speed the process up. First thing for me was this large tape dispenser. Each puzzle gets a covering of vinyl transfer tape to protect it during transit but also to hold all the pieces in place. The roll is 200mm wide and 100m long so it needed something a bit more sturdy than the average tape dispenser. M8 bolts and bearings were salvaged from a very old CNC machine I built (before I bought a laser cutter). It's overkill but at least it's effective.

by (Martin Raynsford) at 31 May 2018 05:37 PM

30 May 2018

Martin Raynsford hackergotchi for Martin Raynsford

Terdragon curve puzzle

My kickstarter campaign received a very welcome boost yesterday when it was reviewed by Mr Puzzle on you tube. I now have twice as many backers as I did yesterday which is a great boost for me. This also led to a discussion about other space filling curves and ultimately a new puzzle for the collection in the form of the Terdragon curve. I will release this file in due course but it seems only fair to keep it as a kickstarter exclusive for now.

by (Martin Raynsford) at 30 May 2018 10:03 AM

22 May 2018

Martin Raynsford hackergotchi for Martin Raynsford

Fractal puzzles now in multiple colours

While I'm slowly piecing together all the different projects I've been working on over the last few weeks for blog publication my Kickstarter for fractal puzzles has been slowly ticking away in the background. It even reached it first stretch goal and I'm now offering the same puzzles with a Mahogany or Oak dye to add a bit of a colour.

It's not too late to join in if you fancy it and if you act quick you'll notice that one of the early bird rewards has become available again due to dropouts. 

by (Martin Raynsford) at 22 May 2018 07:01 PM

12 May 2018

Martin Raynsford hackergotchi for Martin Raynsford

Toothless Dragon Cake

A while back I found myself on one of Dinkydoodle Designs cake course where I made a moving BB9 cake, it taught me a lot about the cake making process and I used a lot of that knowledge in making this new Toothless Dragon cake. The electronic parts are simply a servo, arduino, neopixels and a sound recorder, all fairly common parts but I learned a lot making/baking my own cake.

A 9 inch round cake was baked, cut and modified to form the basic shape required. Two crescent shapes were cut and moved up to form horns, the two eye sockets were added to the cheeks to pad them out a bit. 

The cake was covered in chocolate ganache to smooth out the lumps and bumps and firm the design up. Larger dollops of ganache further filled the gaps between the horns and the head.

Chocolate Silk sugarpaste was used to cover the whole cake. A large rolled sheet was stretched into place, smoothed and trimmed down to the board.

Details were added using rolled up balls of sugarpaste as scales and modelling tools for dimples and nostril details. This part of the cake stops at the top lip so I didn't need to worry about adding a mouth.

The whole cake was sprayed black. I used a water based airbrush paint but I'm informed an ethanol based colour would have gone on better and dried faster. It did suffer from a little beading on the surface but that all kind of added to the dragon skin texture.

The eyes were inserted into the cake at this point, made from white sugarpaste, they were painted green with a brush to deliberately add converging streaks. The black iris was sprayed on top using a hastily made stencil and the shiny spot made by masking off a tiny square before doing that.

Eye lids were added over the top of the eyeballs and the whole thing touched up with more black spray. There was a little over spatter from my poor painting skills and some black streaks up the eyeballs from the paint brush but they all added to the details on each eye.

A lower jaw, row of teach and tongue were formed onto the moving base plate for the whole cake. An adafruit neopixel stick was placed into the back of the mouth to illuminate the mouth when it was opened. 

 A 12 inch board was covered with more sugar paste and effort was made to make it look like paving or a rock formation.

The Toothless head and jaw mechanism were added on top of the board, the mains power supply and Arduino were hidden in a cardboard box under the board, which tidied the whole thing up somewhat.
Hazel absolutely loved it and it went down very well at her party this weekend. The death by chocolate cake is very tasty.

by (Martin Raynsford) at 12 May 2018 10:35 PM

10 May 2018

Martin Raynsford hackergotchi for Martin Raynsford

Fractal Puzzle Update

My kickstarter campaign has now been running a week and has a healthy number of backers, there is still time to grab one of the rewards though and get yourself a puzzle.

If you like my blog then please do share the link on your own social media channels for me. I'm going to have a busy June making puzzles but it's definitely a good way to be busy.

by (Martin Raynsford) at 10 May 2018 03:52 PM

04 May 2018

Martin Raynsford hackergotchi for Martin Raynsford

Fractal Puzzle Kickstarter Successful

I launched my kickstarter yesterday and this morning I awoke to discover it was 100% funded. This is great news so I shall now be making a bulk batch of Fractal Puzzles for people. There's still lots of time to get involved though, I'm even open to stretch goal suggestions if anyone has any ideas.

by (Martin Raynsford) at 04 May 2018 08:01 AM

03 May 2018

Martin Raynsford hackergotchi for Martin Raynsford

Fractal Puzzle Kickstarter Launched

I have just launched a Kickstarter Project for the fractal tray puzzles I made many moons ago. These tricky little puzzles are going to be made of BR Grade Birch Plywood and sanded to a fine finish before polishing with Danish oil so they'll look really good. I'm pleased to be offering them in this high quality finish and fingers crossed the campaign will be successful.

For my regular readers with their own lasers who saw this many moons ago, I would ask that you please share the Kickstarter link somewhere so that I stand a chance of success. The more people that see it, the better.

by (Martin Raynsford) at 03 May 2018 11:02 AM

30 April 2018

Martin Raynsford hackergotchi for Martin Raynsford

Maker Faire UK 2018

I don't mind admitting I was a little bit unsure about Maker Faire this year. I felt like it came around really quickly and I hadn't actually made that many new things since the previous year. I don't like showing the same stuff off again so I had to wrack my brains about something new to take. Clearly I was having a dumb moment and I ended up taking Dawn to the Faire and a selection of the cakes we've been working on. I needn't have worried Dawns work is fairly unique in maker circles and throwing in some moving designs was enough to gain a blue ribbon.

It was great meeting so many blog readers and old friends, thank you all for coming over to say hi. I shall endeavour to post more of the things I'm actually making as soon as I'm able to rather than leaving it all for months. Hi to all the new people just tuning in, hope you don't get too lost down the rabbit hole of previous posts (check out the gallery links at the top of the page).

There's is one thing I won't miss now that this years Maker Faire is over.
"These are our remote controlled cakes"
"Is that really a cake?"
"Is that one a cake too?"
"How about that one?".... and so on.

Finally proof for anyone who asked for it, I did make it out to the Angel of the North by 7am on Sunday morning, a nice simple 10 mile run if anyone fancies it.

by (Martin Raynsford) at 30 April 2018 08:11 PM

19 April 2018

Martin Raynsford hackergotchi for Martin Raynsford

LRP Item Monument

The final piece I made for the Vipers LRP event last month was this monument. I've made a similar display case before so we were trying to improve upon that one. This time the monument could only be opened once all the corresponding rune keys were in place. As the keys were scattered around we thought it would be cool to make them glow when they were inserted into the monument. Some simple LED and microswitch arrangement, side lit the perspex runes. The runes were supposed to be easy to insert and hard to remove. The body was made with ply but painted with a stone effect. I don't believe it fared particularly well in the weather and could have done with a coat of sealant but I shall learn for next time. I even managed to pick up an action shot of this item too.

by (Martin Raynsford) at 19 April 2018 09:10 PM

18 April 2018

Martin Raynsford hackergotchi for Martin Raynsford

Simple tray puzzle

A quick tray puzzle I was asked to make for a LARP event. I assume once all the events were placed in order some kind of secret was revealed. The arrows ensure that the pieces are put in the right way round and show which direction time travels, the events were jumbled before cutting so that the grain didn't give any clues.

by (Martin Raynsford) at 18 April 2018 08:07 PM

16 April 2018

Martin Raynsford hackergotchi for Martin Raynsford

Laser cutter for sale

I've come to the conclusion that I just don't need 3 laser cutters and I don't have space or time for them all anyway so I'm going to have to let this one go. It's barely been used, we bought it with Just Add Sharks and then never used it. I haven't used it for 6 months.

It comes with RD works and should be compatible with Lightburn which is what all the cool kids are raving about. It's also got a really lightweight head so it's super fast. I wish I had more time to play with it.

If you're interested, it's up on ebay, try to snag a bargain.

by (Martin Raynsford) at 16 April 2018 11:44 AM

04 April 2018

Martin Raynsford hackergotchi for Martin Raynsford

Well, Well, Well, Well

Over the laser few weeks I had the joy of making some props for a LARP event. The first was 4 large wells/portals which specific inscriptions upon them. This was largely a woodworking project made from an old pallet, the inscription stones were engraved upon the laser and each stone was weathered using a hot air gun to give it a burnt looked. Some plastic sheet and lighting gave it the effect of being filled with water but it also made them waterproof so that actual water could be put inside them.

As the event has now happened I even spotted some photos of the items in action.

by (Martin Raynsford) at 04 April 2018 09:41 PM

21 March 2018

Martin Raynsford hackergotchi for Martin Raynsford

Stranger Things have happened

Now that I've really got to grips with the ESP8266 I can start to use it in various projects. This one has been on the cards for a very long time and there are already lots of projects doing something similar here's my effort. For anyone still not sure what it is, Stranger Things (season 1) is a tv series about a missing boy, who at one point, communicates with his mum through the medium of fairy lights. This is just a fun way to spell out messages for people but it's wifi controlled so any old phone can set up the messages to display.

These displays are now available in my store as kits or working items, should you want to build one for yourself or read on for further details.

The project is based around some 12mm WS2811 RGB led's. The 12mm lights have a lot of diffusion are easy to mount in holes and don't have to be spaced evenly apart making them ideal for quick installation in a back board like this. The board is 3mm birch ply with a mixture of engraving and line artwork to still give the appearance of fairy lights. (svg here)

The controller is the Wemos D1, I have run a capacitor between the 3V3 and Gnd to filter out any power supply noise to the ESP8266 (much more important when driving motors). The LEDs connect directly to pin D1 on the device and are driven using the FastLed library. The whole thing is powered from the USB connection, if you intend to crank the LED's up to full brightness you probably want to consider an appropriate external PSU that can handle the required current ~1.5A. In this demo the lights are set to <1% brightness and they're still perfectly visible.

The HTML input for this project is so simple I decided not to serve a whole web page from SPIFFS. It's actually just a few lines that can easily be served from a string. Below you can see that it's just a text box and a submit button. The text box is restricted to 49 characters so as not to overload the input buffer on the ESP but this limitation could be easily removed by keeping the data as a string. 

The ESP code is also fairly straight forward, the device is configured to start it's own wifi network with a given SSID and password. It then sets up a webserver to supply the browser with the input page. Finally it responds to an incoming message by saving the data and replying back to the browser with the new message

Most of the interesting things happen in the main loop, firstly we use the fastled library function "EVERY_N_MILLISECONDS" to process our code once every 350 milliseconds, this is a non blocking function and leaves the controller free to deal with the webserver and dns for the rest of the time. Every 350 milliseconds we rebuild a string of colours to display to the lights. Firstly we decide if this is an even or an odd loop, the coloured lights should be on all the time but the displayed letter should flash on and off. I've used a simple list of 4 different colours, LED 1, 5, 9 etc will always be red and because the middle row of lights is reversed the pattern isn't blindingly obvious. Every other loop we simple increase the brightness of the letter we're trying to display. This leads to the first problem though, because the middle row of LED's is reversed it's not as simple as saying A=1, B=2.
The solution is to map letters to LED's, the code currently has 2 sets of mapping functions in 2 different methods. The first is to map the letters A,B,C to the numbers 1,2,3. In the ASCII standard A=65 so it's a simple subtraction but it allows us to map the lower case characters to the same place since a=97. After this first mapping process we end up with the numbers in a standard we're used to. The second is to map those numbers to specific LED's, we could do it with simple subtraction again (because it's only one row that is reversed) but this time I opted to create an array of 27 characters and assign each letter individually. This offers greater flexibility with wiring, with this method I could go up and down with the lights or any random order I chose.
Full Source code here
Improvements could definitely be made in the colouring of the lights, the main loop itself doesn't need to know what colour each pixel is so the colours could all be chosen in the setup function and each loop through the main code simply increasing the brightness of a pixel or decreasing it to turn them 'on/off'.

by (Martin Raynsford) at 21 March 2018 02:41 PM

17 March 2018

Iain Sharp

Everyday Electronics Magazine

Everyday Electronics magazine is something I have fond memories of from my childhood. Much of the practical knowledge I have of electronics originated from things I read there or stuff I tried to make (some of it DID work). For many years my parents kept-up a subscription for me until sometime in the late-80s when I outgrew it.

There is quite a lot of info online about EE’s sister publication Practical Electronics (which it would eventually merge with to create Everyday Practical Electronics) but I can’t find a lot written about EE. Recently I saw an edition of EE that recognised as one I originally owned in a second hand shop. At 20p it was an easy decision to take home.

EE always put a bit of effort in to the cover which is one thing that makes them memorable. This one with the dodgy looking vicar and his assistant is perhaps memorable for the wrong reasons. The projects are typical of what I remember – endless variations on simple circuits with oscillators, discreet transistors, 4000-series CMOS and op-amps. Even the cover project isn’t that exciting, though if you were in the market for an electronic wheel of fortune I guess it would do the job. They might have been basic and (whisper) not terribly useful but building them was still a great way to learn practical skills.

The features are quite interesting and remarkably well considered in terms of content. Magazines like EE were the main source of information in the pre-Internet era and you can almost see how the different features mirror popular Internet content today. In “For Your Entertainment” Barry Fox makes some interesting comments on the current state of flat-screen displays before getting side-tracked in to a discussion of Sinclair’s doomed flat CRT project. The government didn’t half invest in some rubbish projects in those days. Some of the features do hint towards the tide of consumer electronics that would spell doom for much of the old hobbyist world. Another glimpse of the future is the side-bar on direct broadcasting by satellite in “Radio World”. The introduction of DBS as a platform for Sky TV was a huge step towards today’s media landscape.

As a child, my favourite regular feature became “Counter Intelligence” by Paul Young. I liked his witty, caustic and grumpy musings on life in the kind of corner electronics shop that was already finding times tough. I remember that dad used to take me to a shop in Leicester staffed by blokes in beige lab-coats stocked with thousands of components in tiny draws. They hardly ever had exactly what you wanted but could usually produce something that would do the job.

The adverts are a real blast from the past. Many of them seemed to run unmodified for years and years. The spiv zapping his light and the odd boy with his crystal set were almost permanent features. I imagine J Bull (Electrical) always doing deals on vast lots of unwanted items and then finding enticing descriptions to sell them off to the unsuspecting.

So, for anyone who, like me, wants to wallow in nostalgia, or just see what the old days were like here is Everyday Electronics August 1981.





by Iain at 17 March 2018 06:21 PM

12 March 2018

Martin Raynsford hackergotchi for Martin Raynsford

Firmware Reset

During the wifi configuration tutorial I described a method to provide a firmware reset in the case that you forget the user name and password using an additional button (or wire loop). I also lamented the problems of the Wemos D1 board not being able to distinguish between a power cycle and a button reset. Today I'm going to discuss another way to achieve a firmware reset of the device without the requirement for any additional hardware. The method itself is quite simple and we have already used all required parts for the wifi configuration program.

The first thing the device should do when it starts up, is set a flag in the non volatile memory and after a given period of time it should clear this flag again. Now if the device is reset before it has the chance to clear the flag we can tell that the reset button has been pushed twice in quick succession and use that as an indicator that we want to perform a firmware reset.

There are a few items to declare at the start of the program, we'll be using the EEPROM library to write the flag to a memory location that is remembered between boots. The flag is stored as a 4 byte value and should have two different states, these should not be zero because that is the default value for EEPROM, I have chosen 0x55 and 0xAA as they are alternating bit patterns but the actual values are fairly arbitrary. Finally we should declare a memory location to store the value and a length of time to check the value.

There are two helper functions used to access the EEPROM. CheckFlag looks at the memory location for the flag and returns true if the flag is set. WriteFlag puts a new value in the memory location, don't forget to call EEPROM.commit() which is specific to the ESP devices, this is the function that actually writes the data to the memory locations.

In this example we're going to be using the Serial port and built in LED to indicate the state of the device so those should both be set up immediately. For the EEPROM library to work you need to tell it how many bytes of data it is going to be using. This EEPROM.begin step is something I miss all the time with infuriating results. Next comes the actual checking of the flag, if the flag is still set from the previous boot cycle then we know that we need to perform a firmware reset, in this example we note the state by turning on the LED. If we perform a firmware reset we should clear the flag now so as to avoid a double reset situation. If the flag is not set then we should turn it on now.

Finally there is a little delay loop which waits the given time before clearing the flag, I've added this as a blocking delay at the end of setup because I don't like the idea of my main loop performing a redundant check for the rest of it's execution. It could easily be implemented as a non blocking check in the main loop though.

Now when you download and run the program, if you click the reset button twice within a 3 second period you should see the LED turn on indicating a firmware reset state. As usual the full code is at the bottom.

by (Martin Raynsford) at 12 March 2018 12:10 PM

06 March 2018

Martin Raynsford hackergotchi for Martin Raynsford

Gaslands Movement templates

This is a set of wooden templates and tokens for the game 'Grasslands'. The game itself looks like a lot of fun and I like the idea you can get started with any old die cast toys. I loved the new mad max film and this looks like it fits right into that genre.

by (Martin Raynsford) at 06 March 2018 09:26 PM

05 March 2018

Martin Raynsford hackergotchi for Martin Raynsford


I had a request about 3 months ago for a set of tak. The design isn't very complicated so when I actually remember and finally got round to making it this evening I thought I could at least make it look like it took a while to build. I rotated the grain for each tile on the board so it has a slightly different shade for odd/even tiles. The diamonds were cut separately, painted and then inserted on the diagonal. The tak stones themselves were made from 9mm ply which allows them to stand up and a quick capstone was made by stacking 6mm ply. (svg here)

by (Martin Raynsford) at 05 March 2018 11:51 PM

01 March 2018

Martin Raynsford hackergotchi for Martin Raynsford

Hourglass and World book day

I made this hourglass prop for world book day for a Discworld death costume. It's mostly made from 6mm ply but the 'glass' sections are made from 2l fizzy bottles and the 'sand' is rice died blue. It's a little bit sticky because the centre hole is a little bit small but that's actually quite good that someones entire 'life' doesn't pass from the top section to the bottom section instantly.

Hazel decided to go to school dressed as Little Lou and the Woolly Mammoth. All I had to do was make a sew a pocket onto her dress, my wife had the clever inspiration to make the Woolly Mammoth from a knitted poncho and a dozen elastic bands.

by (Martin Raynsford) at 01 March 2018 02:04 PM