A new workshop (part 2)

So the company who built and installed my garden building have done their bit. Now it’s time for me to turn a lovely garden office into a proper workshop / man cave. The included options of wood flooring or carpet tiles didn’t really suit me. I decided on a single piece of grey vinyl flooring from Factory Flooring Direct. I wanted something fairly hard wearing that could stand up to the abuse of a workshop and cope with any spills. The ply that the installers put down was a rather pointless 6mm, so that was ripped up and a sturdy 18mm ply base put down. My brother gave me a hand cutting the vinyl to fit as it wasn’t an easy job – especially with my attention for detail and the fact that I didn’t want skirting board to hide any gaps. It was hard for a number of reasons. Firstly, the roll was too heavy for one person to lift. Secondly, as it was one piece it was bigger than the room and hence hard to manhandle. We did it though. I now had a nice tough grey vinyl floor.

Workbenches

Workbenches fitted

Next was the workbench and shelving underneath. Being spoiled for space somehow made it harder to work out what I wanted and how I would lay it out. I settled on using some solid beech Hammarp kitchen worktop from Ikea. I intended to use oak but when I actually saw it the beech looked better and was cheaper too. The walls only really have decent support at the joins between the prefabricated panels so I used some steel angle iron along the walls and 30mm stainless steel legs to support it. All the metal is from Metals4U. The desk drawers are Ikea Alex and the kitchen units Ikea Metod / Maximera. Basically – it’s mostly an Ikea kitchen! That gives me some desk height (73cm) and mostly workbench height (93cm) space. All of this was meticulously fitted to the not-quite-straight walls so there was no gap. I borrowed a kitchen worktop jig to mitre and biscuit joint the worktop. Lots of work but worth it to get a good fit in the end. The under-bench shelves are just melamine panels – some 30cm and some 45cm deep. You may notice there are lots of sockets. You can never have enough sockets. There are 11 double sockets – some above and some below the worktop. There will also be one on the outside for garden power (hedge trimmer, etc.). The ones by the desk are always powered, but I carried over an idea from my previous workshop. The ones at the workbench can be isolated using an emergency stop button. It’s not just used as an emergency stop. I mainly to make sure that if the kids wander inside all the dangerous stuff and power tools can’t be switched on. I trigger it as I leave.

Moving toys in

Moving toys in

This is how the workshop looks after I’ve moved some of the equipment in. From the left you’ll see:

  • My desk for coding and microcontroller work (where I’m typing this right now)
  • Oscilloscope and solder station
  • An Up Plus 3D printer
  • The red emergency stop button on the wall
  • My small Proxxon MF70 CNC mill
  • A 40W CO2 laser cutter
  • A small metalworking lathe
  • A mitre saw
  • The kid’s workbench. They want to be like their dad!
  • The keen-eyed will have spotted 2 fire extinguishers (powder and CO2). I’ll be burning things with a laser in a primarily wooden building so a sensible precaution.
You'd never know it was a workshop from outside

You’d never know it was a workshop from outside

All this stuff only really takes up half of the workshop – the mostly hidden half. The right hand side should soon be getting a sofa bed (for the occasional brave visitor), fridge, etc. It’ll be a family space and my wife will have her input. However, I have said that if a scatter cushion appears it’ll have an accident with the mitre saw.

There’s still workshop stuff to do. There’s plenty of storage space under the bench but shelves and wall-mounted tool boards are coming soon. The laser isn’t usable yet as it has no exhaust venting. I’m also planning to put a sink in there to allow making a cup of tea and washing hands. It’ll drain onto the ground rather than have any plumbing back into the drains so it’ll be fairly limited. I’ll let the rest evolve as needed. Maybe it’ll never happen but the plumbing is there.

A new workshop (part 1)

Current workspaceMy current workspace at the back of the garage seemed like luxury at the time. Rather than just squeezing everything onto a small piece of kitchen counter next to a sink, I made a custom L-shaped workbench that was built like a tank. It had shelves below, some above and plenty of power points. Unfortunately I soon filled the space with a laser cutter that was bigger than I expected. Then the old space beside the sink became occupied with a lathe. It’s true that stuff grows to fit the space you have.

Since we moved into our house 7 years ago, there has been a bit of ground at the bottom of the garden under the shade of some old plum trees. Only brambles grew there along with builders’ rubble and a small shed. It was fenced off and more or less abandoned. The time eventually came to do something about it. The full space was 9m x 4.5m. Trees and a fence were removed. Earth was shifted and the ground was flattened – very hard work. About two thirds of this space was about to become a new workshop, with the remaining third for the kids to have a swing, slide or something.

I shopped around for a while. Dunster House looked OK, but had enough bad reviews online that they were discounted. Then I found The Garden Office. A bit more expensive but much better. They’re a really great company who I can highly recommend. I went for a building with internal dimensions of 5.5m x 3.8m – about the largest I could go and still leave a reasonable space for the kids. I was very impressed when visiting their showroom. Unfortunately they’re now so popular they had a 3-4 month lead time.

Workshop base in progress

Workshop base in progress

Eventually, one Friday the sent out a team to lay out the base – some very helpful guys who got it as close a they could to the boundary to maximise space. Rather than the more usual laying of a concrete base, they drill about 20 holes and poured concrete down to form pillars for the structure to rest on. Far less hassle than a full base and it seems to work really well. Each pillar has some adjustment to get it perfectly level

Workshop build in progress

Workshop build in progress

Then on the Monday to Wednesday of the next week the rest of the build went ahead. Once again, a really great team who seemed genuinely keen on providing what I wanted rather than just getting the job done. I knew I wanted lost of power points but I had no idea where. They were happy to run extra cabling where I thought I might want them and to leave some panels loose for me to get in there and wire it all up. They also left the flooring unfitted at my request so I could fit a thicker plywood base and a custom vinyl floor.

The only minor glitch came with the laying of the armoured power cable to my new workshop. Rather than waiting for an electrician to sign it off, the build team buried the cable themselves (along with some CAT6 and water pipe). There was a bit of hand dug trench they didn’t back fill, and the depth of the cable here didn’t look right. I dug a few test holes and found it hadn’t been bured to a safe depth – despite the trench being dug deep enough. Maybe they didn’t think anyone would be picky enough to dig and check! Anyway, it was remedied quickly and without any quibbling by the Garden Office team. I always say you can tell more about a company by how they handle the odd mistake then if they make no mistakes at all. Once again they did well. If you’re after any sort of garden building I have no hesitation recommending The Garden Office or their sister company Green Retreats.

Workshop installation finished

Workshop installation finished

Well, my lovely new garden building is up. Now it’s down to me to sort out the inside and turn it into a workshop…

NFC login (version 1.0)

After my experiments with NFC readers I felt it was time to actually create something useful to work with my NFC implant. At work I need to make sure that my PC is locked whenever I leave my desk. It’s not that I work with anything really sensitive, it’s just that given half a chance my colleagues will certainly send an email on my behalf admitting to unusual sexual inclinations or offering to buy everyone biscuits.

I decided the easiest way to do this was with keyboard emulation. It doesn’t require me to have any privileged domain access, modify the PC or install anything that compromises security. Plus, it should all be possible using a MSP430F5529.

The launchpad, booster pack and antenna.

The launchpad, booster pack and antenna.

My proof of concept involved a MSP430F5529 LaunchPad and a . I made sure that I could emulate a USB keyboard, implement a USB CDC serial port and read my tag id.

The USB side of things was adapted from some of TI’s example code. The NFC stuff was a little trickier. The Booster Pack is sold bundled with either the G2 or F5529 Launchpads. However the sample code is surprisingly complicated and only supplied for the MSP430G2553. Porting it over to the MSP430F5529 should have been fairly simple – just changes to some in assignment and clocking. It somehow took me ages but I managed it in the end. I must publish my ported code to save other people the same trouble.

I combined them all together to implement the following:

  • A USB CDC serial port allows me to set the password (but not read it). It’s stored in the microcontroller’s flash so persists when powered down.
  • Pressing one button on the launchpad send Windows-L to lock my PC. (Not actually easily accessible in its current form.)
  • It scans continuously for NFC tags and if it sees mine it sends Ctrl-Alt-Del{password}Enter

The 2 part 3D printed case for my NFC login

The 2 part 3D printed case for my NFC login

Hardware wise for version 1.0 I went with the setup from my previous including a DLP coil antenna and a cheap bit of U-FL to SMA cable from eBay. I don’t intend that the final version will be using a dev board and booster pack. It’ll be a custom etched PCB, but I decided to take the same approach as with Agile software development – produce a minimum viable product first and improve later. If I don’t ever get round to a nice neat version 2.0 then at least I can actually log in with my implant.

A view showing the installed boards and antenna

A view showing the installed boards and antenna

I 3D printed a case that allows the launchpad, booster pack and antenna to slot in. It comprises two parts that clip together and a couple of magnet to hold it firmly against the PC case on my desk. The case is 3mm thick but only 1mm thick by the antenna coil so it reads fairly easily.

OK, it just looks like a plain yellow box

OK, it just looks like a plain yellow box

The final version looks a little dull. It’s a plain box that was almost done in black, but I happened to have yellow filament in the printer. All that happens when I successfully scan my tag is that a red LED shows through the case for 5s whilst scanning is temporarily disabled and my PC unlocks.

I’ve got a little bit of tidying of the code before I include it. As it’s evolved from two different lots of sample code in different styles it’s a little bit messy. I’ll also attach the STL files for the case – designed once again in my 3D modelling package of choice OpenSCAD.

Source code (still messy) and STL files (under files folder) are now available at https://bitbucket.org/fredmurphy/public/src/127c1b2f26305bd8b2b2184084927da72457f9e5/LoginNFC/?at=master

NFC reader for the xNT (part one)

I’ve had my xNT NFC implant for a few months now and I’m very happy with it. The main thing I’ve used it for is opening my garage door. It was great to use it with an existing piece of commercial kit and get used to it, but I always wanted to build some custom things to use with it.

Some NFC readers

Some NFC readers.

The simplest way to get started was to find an existing NFC reader that I can interface with a microcontroller. A scratch-built reader will come in time, but for now this is the first step. I tried a few reasonably cheap NFC readers hoping that I’d find a gem amongst them. The ones that I tried are shown. There’s the (red) DLP Design DLP-7970ABP booster pack for the MSP430. This suits me as I’m a MSP430 user and may well use the TRF7970A to base my custom reader on. Next is the (blue) RC522 based reader I found on eBay. This was chosen just because the RC522 is a commonly used chip so there’s lots of sample code out there. Third the (green) YHY502. This is just something I found on eBay from China sorting by price. Lastly the (black) ID20-MFIA. I chose this as I’ve used the company’s ID-20 125kHz reader.

OK – so if you’ve stuck with me this far you will probably want to know how they fared! To be honest they were all fairly similar. They all required the implant to be right over the PCB antenna trace (not in the centre). The alignment had to be right so without rotating my hand or the reader it worked along two sides of the trace. Whilst the ID20-MFIA didn’t have a visible trace it behaved similarly. It was also more of a pain to use too. I tried to get a quantitative measurement of range but it was tricky. They could all just about read through a piece of 3mm acrylic. Just. In practice you would want to be closer than that. Ideally with as little as possible between you and the PCB. Not as good as I’d hoped.

However, two things give me hope that we can do better. Firstly, my Samsung Ezon SHS-2320 lock seems better than that. I generally place my implant right against the reader but it seems to read well and consistently. I’ll have to do a teardown soon.

Secondly there was this post by Mathieu Stephan on Hackaday. As you can see Mathieu’s made far more progress than me. He was also happy to share his results, including schematics and the values that worked for tuning his antenna. What an awesome guy.

Mathieu’s work on inductor-based readers got me poking around a bit and I stumbled over this ferrite antenna also from DLP Design. Whilst I intend to etch some boards and try out Mathieu’s design, I’m fairly time-constrained by two young sons. I thought it’d be worth seeing if this off the shelf antenna would do the trick.

Adding u.FL connector

Adding u.FL connector

Cutting PCB trace

Cutting PCB trace


There were a couple of things I needed to do to get this working. I had to cut the trace to the PCB antenna on the rear of the board. It’s a 4-layer board so lucky it wan’t on an internal layer. I also had to add the unpopulated SMT u.FL connector to the board (marked CN1).

DLP 7970ABP and FANT

DLP 7970ABP and FANT

Finally one cheap eBay u.FL to SMA (note not RP-SMA) cable and we’re sorted! So – how did it perform? Not too bad.

I don’t think it was ever possible to get a huge read range, but it’s definitely better. It will now just read through 5mm of acrylic and whilst it still operates better if oriented correctly with the implant it’s not quite as fussy. It’s a worthwhile improvement and if you’re making your own board it would definitely be worth basing it on a coil rather than PCB antenna.

There are some differences between the DLP’s and Mathieu’s designs. There’s still the Ezon to take apart. So I’ll keep going in my search for the perfect reader. Also, it might still be possible that the right (i.e. smaller) PCB trace is even better. I’m also working on the code for my first xNT project, so stay tuned…

Adding wireless charging to the Nook Glowlight

A while ago when Barnes & Noble put the Nook Simple Touch on sale I got one – thinking that for £30 then at the very least I’d rip it open and use the eInk screen for something geeky. I ended up liking it and actually using it for reading books. I liked it even more when I found it was possible to add wireless charging.

Easier connection points on the Nook Simple Touch

Easier connection points for the Nook Simple Touch

I was very impressed with Tom’s original work. I did manage to make a slight improvement by finding some easier points on the PCB to connect to – a couple of test points marked T292 and T334 on the more accessible side. You can see these connections on the photo.

When the new Nook Glowlight came out I thought it was time for an upgrade, but I’d really miss that wireless charging. Well I’ve got some good news for you. It’s possible! Not only that, but I’d say it’s probably easier to do. We still use the same Galaxy S3 wireless charging pad. Mine was £3 shipped from China by and I had no problems. I bought from befdi but there are many other sellers that I’m sure are fine too.

Disconnect the battery

Ease open the case. No screws, just clips.

Open up that case. There’s no SD card to remove or screws holding it together. Just take the rubber trim off and you’ll see some small white tabs holding the back on. I found that flipping it over and applying some gentle pressure for a small screwdriver or even a butter knife made it easy to take off. There are 2 top and bottom and three on each side. As you can see them from the front they’re easy to pop open without breaking or marking your new Nook.

Disconnect the battery

Disconnect the battery

Then open it up like a book. You’ll probably want to disconnect the battery as a precaution, but that’s all the disassembly you’ll need to do. Whilst working out what to do, I disconnected the display (just pop the connector up off the PCB), unscrewed it (6 x T6 screws) removed the PCB and disconnected the ribbon cable for the IR touchscreen, All of these turned out to be completely unnecessary but I liked to have a good look around anyway. No warranty-voiding stickers need be removed.

Locate these test points on the PCB

Locate these test points on the PCB

Whilst the PCB on the Glowlight is far more densely packed than the Simple Touch, and some of the test points are absolutely tiny, this modification turned out not to be as difficult as expected. The only points you need to access are reasonably large and marked GND and V-BUS. They’re on the more accessible side of the PCB even though the USB connector is on the other. Dab a little solder on to tin these test points, tin your wires and solder them together. Pre-tinning both means you transfer less heat to the board.

Note the polarity

Note the polarity

Now it’s time to connect to the charging pad. Note the polarity of the connection from the photo. Maybe measure yours with a multimeter just to be sure. I found when soldering that the two gold pads to connect to the phone completely came off. It’s easier with these out of the way so don’t worry. Be careful with the heat though. The pad seemed like it would melt fairly easily.

Pad facing the wrong way

Pad facing the wrong way

Unfortunately my first attempt at locating the Qi charging pad didn’t work. I positioned the pad as shown with the connectors facing away from the Nook and towards the charger. I figured there would be less chance of a short. Placing it on my Nokia charging pad did nothing. I was relieved that the Nook and USB charging was unaffected. It turns out that it won’t charge unless the “Wireless Charger” logo faces the Qi charger. I measured the output voltage both ways up and if it’s the wrong way you get nothing at all. I was surprised but that’s how it was. To be honest I hadn’t thought of this when I modified the Simple Touch. Just luck that it was the right way round I suppose.

The right way round this time

The right way round this time

My second attempt flips the pad around and so has the connectors nearer the PCB. Whilst these shouldn’t actually short anything because they’re a little about the PCB, cover them with a bit of tape anyway,.

Well – that’s it! Pop the case back on and you’re done. £3 for the receiver and maybe 15 minutes work and you now have a wireless charging Nook Glowlight. Apart from a couple of tiny blobs of solder on the PCB and a small cutout from the webbing on the back case your device is unmarked. You’d never know from the outside and could probably remove it if you ever needed to return it under warranty and nobody would notice. Your warranty is void though. You know that, right?

Freewheeling Friday

What a totally random Friday I just had. If you’re a fan of Ross Noble then you might have seen his series Freewheeling where he responds to random stuff on Twitter and heads off round the country on his motorbike. Well, he’s currently busy filming for series 2 and when he tweeted this I thought I’d mention my NFC implant.

I am looking to feature the following on freewheeling.
Ventriloquism
Taxidermy
Alternative people(tattoos body mods etc)
Can u help

The film crew in my garden

The film crew in my garden

A few messages back and forth with his production team and he turns up with a film crew to have a chat. We spent about 20 minutes or so in my back garden chatting about the back door to my garage / workshop which has an NFC-enabled lock. My wife also had a chat about how she wanted nothing to do with implanting it for me. She pretended to be all aloof about having a celebrity popping round, but when it looked like she’d be out before they turned up, she managed to cancel her other engagement!

Me, and a firmly shut garage door

Me, and a firmly shut garage door

I also showed him the Fisher Price records and the laser. We chatted for a bit about motorbikes while the crew sorted out the next destination – a taxidemist who stuff mice in positions reading the newspaper, etc.

Adam (two and a half) was too shy to join us.

Adam (two and a half) was too shy to join us.

He seemed to be a really nice genuine guy. And whilst it looks like a bit of fun it seems like really hard work to make it look that way. They do 2 weeks solid filming morning to night 3 times. Each week turns out to be a single episode. My older boy Adam is motorbike obsessed and loved his KTM SuperDuke. Ross even said he could sit on the bike, but a bout of shyness meant that he wouldn’t.

All in all, a fairly unusual day. Then off for a stag weekend…

Oh yeah – it should be on around the end of the year. I’ve no idea how much footage they take or how likely I am to make the final cut. It’s a great series though. Watch it anyway.

CNC controller enclosure

Laser cut acrylic enclosure

Laser cut acrylic enclosure

I converted my Proxxon MF70 mill to CNC quite a while ago. When I was testing things out I wired up the PSU and controller board and just threw them in a Tupperware container so that nobody got electrocuted. It even had the lid open to allow the cables (including 240V mains supply) in. A temporary hack if ever there was one. You know how temporary hacks are though – they tend to stick around longer than intended.

Close up of the connectors for the axes, e-stop and LED

Close up of the connectors for the axes, e-stop and LED

Well, I finally got round to making a proper acrylic enclosure. I attempted to mill one ages ago, but struggled with the small working area on the MF70 and abandoned it. This one is laser cut. It’s held together with machine screw’s and has two shelves – one for the PSU and one for the TB6560 based stepper controller. I particularly like the rounded piece for the power LED and the hexagonal grid for venting.

I’d be happy to share the design files if anyone is interested, but I doubt anyone has exactly the same setup as me. I also altered things as I went, so I don’t have any “final” versions.