So, whilst waiting, I’ve been playing around a little with the CAD and the ‘extras’ for the keyboard kits – the Real Mini 42″ scale floppy disc.
The cocnept is – to have a ‘working’ floppy disc that you can play games off.
Still some work to do optimising, but i’m rather happy with this second attempt at printing. The metal part has been cut out on my KNK ZING vinyl cutter and has been extracted from a projected sketch.
That works for the Amiga side – But, people will need a way of getting the games onto the floppies , so – Early days yet, An External mini floppy disc drive for a PC!
This was surprisingly quick to knock up . I found an image of an eBay sale, imported as a canvas, ‘traced the canvas’ and set the scale around the floppy disc slot. I’ve never owned one of these so had to work from many pictures. Still a lot more to do, but fundementally, i’m keeping the exact same PCB’s and mechanism / holder that i’m creating for the A500 Mini. Just putting it in a shell and using a different USB cable….
I will be releasing the design files publicly for this thing so anyone can print up / adjust and make their own ones as international postage gets expensive for things larger than 25mm high here in the UK…I’ll also offer up these for sale with keyboard kits
And, if you’re wondering, just how many picures…and files needed to create a floppy drive and disc…….Here’s a quick snapshot of my A500Mini folder – just for the floppy! and these are the ones i’ve kept for now….
Three PCB’s are pretty mich ready to go . Just last minute checking, double checking, triple checking needed!.
I’m lacking lemmings on most of the boards, but be assured, there’ll be a few on the production units.
I’ve also now pretty much finished the keyboard CAD…Had to do yet another iteration to allow for the new switching mechanism i’m using..It’s really been a case of design, print, test, iterate, repeat!…Still ‘a few months away’ as always, Real life is taking over a little, meaning less time to perfect this lot.
On the plus side, I really do think this Prototype 2 will be ‘good enough’ for general testing and useage. Everything after prototype 2 will be geared to making it easier to install and add (or remove) extra features. Lots of pics after the break……………..
First working keyboard keycaps are off the printer! Only this bit to show as most of the print failed 😛
Well,, 3 prints failed, I’m trying to learn how to use my Photon Mono-X, so far mostly unsuccessfully, these were printed using a known good combination of Photon Mono and Commodore Brown resin 🙂 ….and still it partly failed!!
Next, I have to optimise the design for printing. I’d added some features to make them work better, but, those features don’t translate to printing very well, D’oh! (That’s called not doing Design For Manufacture!).
Resin printing can be a hard beast to tame, especially when printing 94/98 individual items (98 if I can two keyboard types!!)
This first print is literally an ‘auto supports, Jab a few extras on, hope for the best’ quick test to prove the mechanics. When the design is finished, I’ll need to spend a couple of solid DAYS (maybe a weeks worth of evenings) adding thousands of supports MANUALLY to ensure every keycap comes off the print perfect!
That sounds a lot, but printing a single item is different than printing the same item hundreds of times, so it’s really worth the up front investment in time.
And, speaking of time, I’ve just clocked about 600 hours evenings and weekends, on this project now 😛
I’m rather happy otherwise, next week, I should have a full working keybaord to demonstrate 🙂
Along the way, I’ve been tweaking some other bits – The Real miniature fake USB Floppy disc is progressing nicely
I’m on the second design of the 3D Printed insert, this will hold the USB PCB and also be the interface and guide rails for the floppy.
I’ve also received my memory solution for the discs, it fits superbly! – it can be seen in the badly printed / broken green area. The dimensions are exactly the same as the 3D print i’ve put in
I’ve also purchased some silver brushed effect sticky foil so I can re-create that beloved silver cover….and even have created the label ready to cut out on my dusty KNK ZING vinyl cutter thingy. Hopefully I can make the adhesive sticky enough!
I’ve also started stocking up on Printer resin, ordered a load of sample parts from Aliexpress, test fitted PCB’s…..started on box design, started tweaking firmware, there’s dozens of tasks to do!
Quite a lot of progress, but it doesn’t look like a lot of progress.
Firstly, I’ve had to re-do most of the keyboard CAD – I simply didn’t like the ‘blocky’ effect of the wider topped keycaps I’d created – as you can see below they look a lot more square in real life than they did in CAD…
I’ve now clocked well over 200 hours developing this set of keycaps, likley there’s going to be tens more tweaking / optimising!
So, along with the less blocky (more slopey) keys, I’d discovered my workflow in CAD had created tapered keys – the tops when viewed from above look like parallelograms, wheras the original Amiga had more square keys – it was quite a lot of work to alter this – see the parts below by the red arrows – the bottom bit is in towards the middle more than the top bit.
Have been tweaking things over and over, I’m now finally ready to…….
I think there’s going to be a few people out there actually using this keyboard in anger, so i’ve widened the keyswitch tops a little and added larger fonts to make it easier for someone to fill in some colour if they chose to do so.
Some other progress –
The Floppy Disc insert! – a FULL scale floppy disc fits well
I’ve refined the floppy disc insert thingy – I really think I can make this work – lots of parts on order so i’ll iterate this design over the coming weeks. I’ll do the first prints of the plug in module soon
Speaking of prints….
I knocked up a few of the mini-Floppies. Printed in various orientations to see if it’s even possible to do these. The best print is the angled one..Turns out, it’s going to be tricky as can be seen from the various failures above. Have re-designed a little and will run off some more sample prints soon. The supports on this one will be critical and hopefully not so wasteful as the C64mini keycaps were.
And, almost finally –
Here’s a collection of ‘stuff’ rendered so far. The Keyboard PCB is unfortunatley upside down – due to the way I started modelling stuff, no big deal but makes the renders look odd. The case slopes don’t need to be modelled (at this time) so i’ve just left them flat for now.
There’s loads of parts waiting to arrive in the post, but there’s also loads I can be getting on with, not just on this project, but on numerous others also!
I’ve spent a couple of days designing, and and a today, spent nearly a hundred quid at JLCPCB ordering a bunch of prototypes
I had to bite the bullet and spend some money as I now need to move on with the Keycap CAD. I have a big concern about the fitting of the printed keycaps onto the smaller switches. I’ve gone with ALPS switches as they used to be a huge brand name back in the day and i’m hoping should provide some consitency.
The prototypes will help also to test and develop the PRK Firmware i’m planning to use.
The ‘Clamp’ adaptor is fairly non-functional. It has a Rasperry Pi Pico footprint onboard and a 40 pin FPC style connector to act as a ‘stand-in’ for the Raspberry pi Pico which is currently on the back of the main PCB.
The whole idea of the ‘clamp board’ is to allow an ‘ease’ of installation – I’ll use some Pogo Pins to sit on the test pads by the 3 USB sockets on the back of the A500 Main board.
The plan is to have a basic matrix keyboard PCB, which connects to the clamp board via the 40 pin FPC.
The clamp then accesses the USB and hopefully it can all be fairly easy to assemble.
I’m also testing the Fake floppy connection with the clamp board – no idea if that’ll work or not, we’ll see.
Now the long-ish wait for Aliexpress to deliver my connectors, pogo pins, and a couple of weeks for the Cheapest post option of JLCPCB to ship the assembled keyboard! – nearly 100 switches and diodes on this one, those can be automated in assembly. I’ll need to hand solder on the rear the FPC connector but those are easy enough!
I received yesterday my A500 Mini! – Haven’t even powered it up yet 😛
My assumption about the 43ish percent scale was about right – and the work i’ve done so far on the PCB pretty much stays the same – which is a relief.
However, till now i’ve been using a full sized Amiga 500 to infer dimensions. I can’t easily do that going forward as the scaling factor for the Amiga is ‘a bit weird’ – I think I can see why it’s been done, but, it’s far far easier to re-start the CAD from new…or at least shift the fusion timeline back to the beginning and see what i can recover 🙂
Much more to do, will update later as there’s also a few ‘gotcha’s i’ve found, and a few ‘woo’ moments also!
Had a major ‘procrastination’ research binge over this past week, trying to figure out just how I could cheaply and reliably get 3D printed keycaps onto tiny switches.
I’ve found I think two ways that can be successful.
The first – a small tactile switch, with an ‘oval’ or keyed button. The A500mini’s keys are probably just over 7mm square, I can’t use the 6mm switches i’ve previously used as there’s not enough space.
Something like the below could do the job – it has a slightly tapered switching bit in the middle, so I can do push fit keycaps that should grip on. it’s also 5mm on a side, and 3mm on the other, this frees a huge amount of PCB space up, BUT, it’s still quite ‘large’ and the top isn’t tapered as much as i’d like. visually it looks fine, but datasheet suggests it’s straight
There’s also an older, more ‘retro’ type of approach. So, i’ve gone and knocked up a very rough CAD drawing – it’s innacurate, until I get an actual A500Mini in my hands…
and i’ve gone and emailed half a dozen companies to request some MOQ’s. and some pricing!. I’ll fill this in later with more specifics
So, that means getting firmware working should be a breeze.
There’s becoming quite a few ‘RP2040’ public circuits available now, so that part’s done and dusted on my PCB, all i’m really waiting for is to get some accurate measurements so I can knock up a prototype!
Minor update on progress…made the schematic a bit clearer for me to understand, also am doing a dual footprint style setup – where I overlay multiple component footprints incase one becomes hard to get.
I’m also creating two ways of driving the matrix, an on-board RP2040 chip and, if they become hard to get, a seperate daughterboard which can house a Pi Pico
Kinda pausing PCB development until my Amiga 500 Mini device arrives in the post, but i’ll be playing with the PRK firmware next!
after a good half hour of searching for the Amiga Key font, including various terms like “lop sided font”, “font with one side thicker than the other”, “fonts that look like broadway, “broadway serif” and even google image search for
I finally found the correct font with a quick search for “font used for Amiga key”
Another small update! – I think i’ve cracked the basic model of the keyboard.
To get this far has taken dozens of hours of interweb sleuthing and watching youtube videos to watch how the light reflects of genuine amiga keboards to see how i can capture the curves of the keys.
Most keys seem to be a very simple U shaped dip from the edges of the keys! the dip is always the same depth, so the wider the key, the smoother the dip!
Two different keys were the Space bar – this has a slightl raised curve at the top ratther than a ‘dip’
and the Enter key – which has a more complex bowl like dip in, that key probaly took the longest to figure out but the top is essentially is two U shaped dips, one for the top of the key, one for the bottom. I’ll go into more detail in a future post
For now, this is accurate enough for me to be able to develop the font to embed in the keys! I’ve made the model reasonably parametric so I can change things around a little to match the exact key spacing of the mini once I receive it. At this scale, i’ll have the same 0.5mm clearance between keys as I had on the C64 mini, though I plan to increase it a little more in the final product.
Not much of an update, just a couple of pictures to show i’m still slowly tinkering.
The keys do seem much easier to model as they’re less curvy. there’s only a top ‘dip’ in one plane which is easily extruded into the keys using circles that are varying radius’s to give a 0.9mm ‘dip’ in the top of the key. that dip will be much less prominent when the whole thing is shrunk 50%, but I like to try to be reasonably accurate.
Early days – Square keycaps to create a layout grid in EasyEDA
Little bit of progress now – Thanks to this superb thread – and some other random pictures, I’ve gotten fairly close dimensions to a proper Amiga500. Same old story, Mine’s down my parent’s in Wales and I procrastinate over picking it up , so waste too much time analysing, measuring stuff online! It’s not accurate, but is close enough to get a 50% scale PCB layout done now, and tweak accordingly once the real A500 Mini is released
Incidentally, someone confirmed that square keys are 18mm on a base (thanks Dan) from that single dimension, i’ve been able to recreate most of the keyboard, with only now some uncertainties as to the remaining key sizes.
Why I’ve created this CAD – to use as a template to create a PCB!
Project the ‘keyboard’ bodies into a fresh sketch
It makes creating a ‘clean’ Sketch really easy. Just project the switch bases onto a fresh sketch, Export that sketch as a DXF….then import DXF into EasyEDA..
Of course, I’ll need to scale this lot down 50% to ensure things’ll fit in the Mini!
In some good news, I may not need to fully design the CAD for the Amiga Keycaps as someone in the scene has reached out and offered their CAD designs. Best case, I can simply modify their designs. Worst case, I can use their designs to measure the curves and ‘simply’ recreate in Fusion360. Either way, it means it’ll be a LOT quicker than the C64 Mini’s keycap development
Finally, onto the PCB design – I’ve already replaced the horrendous keyboard matrix schematic with one more resembling the genuine Amiga’s. Unlike the C64 Mini one, this one won’t be fully compatible with an actual Amiga due to there being some periphery circuitry to convert the matrix into a serial format for the motherboard to receive. BUT, keeping the same matrix – for everything other than the ‘standalone’ modifier keys should help some people to do ‘other stuff’ with this.
Oh, and I noticed that some of my previous assumptions about the 32u4 being used in the Mini were incorrect – It’s a bit bigger than I’d realised. it has 26 GPIO (kind of) when used in the raw chip form!…I thought it was 20 (D’oh!) that means you can (in theory) have a matrix with 144 switches AND a couple of pins left over for LED’s!!
These are the first brand new work that i’ve done on the inserts. The previous LED inserts were hacked out of the STL’s the ZX Spectrum Next team released some time ago. Since those early mesh hacks, i’ve learned quite a bit more on Fusion360 (which is entirely free for makers!)
Not much of an update, but i’m slowly picking back up on this again, personally, it’s been quite a tough 2021 , leaving me with little capacity to do fundemental development stuff…On the plus side, i’ve been in ‘something shiny’ mode for quite a while and literally shotgun blasting ‘fun’ ideas for new things, a few of which have been developed further and you’ll read about once they’re better baked.
And a few other things….all of which are quite finickitey and throw a wobbly at the slightest provocation! – Linux is fun eh!..
I’ll eventually get around to step-by step documenting and linking each step to ensure a good build environment so that others can duplicate what I’m doing
Once it’s all compiled, I drag the .uf2 file over to the pico (after holding bootsel whilst plugging it in) the thing reboots and becomes a keyboard
Ensure the Keymap is correct
Finish the basic keyboard layout, testing all basic keys
Introduce shifted keys
introduce ‘layers’ to ensure special keys are correct
introduce fancy stuff
Where this is going……………..The RP2040 Chip is fairly priced against the 32u4. I’m hoping that I can eventually switch the C64mini keyboard over to a fully SMT ready assembled kit – just add keycaps. And, i’m hoping I can do that for the Amiga Mini!, as much as I love soldering 600+ points, I appreciate some of you out there don’t!
And, I’ve another TOP SECRET project on the go also…It’ll blow yer mind! but, in 2022 that one, it’s a long burn that ‘looks’ finished (i’m holding it in my hands now!, all 2 circuit boards and about 100 3D printed pieces) but, needs quite a bit of work behind the scenes.
Also, Blinkenator, slow going, but I’m really trying, it’s just hard getting over this hurdle where it must be soldered….one last thing to try!
And, final before I go to bed, the C64 mini running the keybaord upgrade kit with pi Pico transplanted brains!
It’s being captured via a HDMI capture dongle and OBS studio so I can use my laptop as a test monitor!
First – A small project being worked on in the background. I’ve been struggling to keep the momentum going on the blinkenator – for a myriad of reasons, so i’ve distracted myself a little with ‘something shiny’ which at last count has nearly 200 items in the BOM, including 70 3D Printed parts!
The picture shows the lower half – revision 4 after being supported and currently on the resin printer! has to be at an angle as it’s just a little bit too tall to print vertically in the Anycubic Photon Mono
Ain’t gonna give any more information until this one’s working and ‘ready’ – just the odd vague teaser here and there
The other thing – The Semiconductor shortage…I’m having to pause briefly the C64 Mini keyboard projects as i’ve run out of Arduinos.
Unfortunatley, they’ve now tripled in Landed price in most places since I started purchasing them!
The switches have gone up 50%,
The Diodes have gone up 100%
That now means, at £30 a basic kit, profit margin’s a little slim..I may need to raise the price to £35 at some point, I just need to make some time to take stock of what parts I have and re-price based upon being able to order more when this lot runs out.
Amusing that it’s the arduinos as i’ve 50 of the wrong type still here – I’m going to try selling them to make some $$ 😛
[edit – as typing this, i’ve found a local seller at old prices!, I just snapped up 10 arduinos at a fiver a pop – will be kitting up over the weekend]
Have been having a little bit of a creative Block with the Blinkenator. It’s a typical story where ‘something shiny’ has been spotted and has been taking up the small chunks of time I’d normally allocate to this stuff.
I’m awaiting on those Pogo pins to test the next revision…….But, have also seriously re-thought the programminator / tester device…….And, we have what you see above
40 Pin Raspberry Pi connector will allow some ‘playing’ around with the ESP device, and programming of the Arduino. I’ll need to figure out exactly how to write the software to do it- but, there’s dozens of tutorials out there so i’m confident.
Programming could also be done via a standard 6 or 10 pin ICSP device (that can be bought for a few quid off Ebay) directly on the blinkenator itself, or via the 9 pin connector at the bottom – which breaks out to the Programminator.
The Programminator also utilises the J15 connector of the Blinkenator – This should be a great way of testing the new Pogo pins connections as my Specnext J15 is fairly well shot
There’s 2 new holes – 57mm spaced (same as a Raspberry Pi!) which can sit standoffs which match the positioning on the programminator (rasperry pi footprint)
Took quite a while to get this far – now at least you should be able to see the LED’s doing their stuff whilst connected to a Pi and a test board!
I’m very close now to getting this new board done as a BETA….next step is to print out, test fit and tweak
In other Interesting news, JLCPCB ‘s NEW version of EasyEDA exports OBJ files! I’ve literally just discovered that you can EXPORT a 3D model of your PCB.
Assemble your bits – whack ‘print’ and, send to a 3D printer. Or put into your favourite slicer program and do the same – I’ll have a little bit more of a play tomorrow – it’s 11PM now. Now, to use the Resin printer or the Filament one 🙂
Oh, as for the ‘something shiny’ that’s come along…..Checking the logs in Fusion360, I started back on the 8th February. Since then I’ve easily spent 200+ hours editing, tweaking, Learning. I made the first 3D print last week. There will be many more prints till it’s ‘final’ .
There’ll be a few versions of electronics inside, Basic version will likley be some type of Raspberry Pi – Compute Module , A design is well underway. I’m also possibly thinking of dabbling in FPGA, though a 6 layer double sided PCB is a bit daunting, I’m designing one anyway after gaining a big bit of help from someone who’s already familiar with FPGA’s
I’m being vague as I really don’t know where this one’s going. I’ll need to show this publicly, once it’s done and then see what occurs. I’ll need a new, larger resin printer for sure if it takes off though, it uses the entire build volume of my Anycubic Photon Mono printing off the two larger pieces at an angle!
I’m still trying to make this darn thing solderless….and, I have possibly a lead, which ain’t cheap…but will allow me to offer two versions.
Those gold things are pogo pins. But, slightly less common ones with a 1.2mm diameter pin part. This should sit quite nicely into the Next’s 1mm holes in J15…..except in my excitement, I forgot about that darn keyboard connector!
Using these requires yet another redesign, but a relatively minor one that only needs the connector stuff soldered on the reverse of the PCB…
On the plus side, this could make end user fitting of the inserts a little easier 🙂
As for ‘expensive’ – those pogo pins are around £1 each and at least 6 will be needed, more if the wifi relocation is used!
A quick pictorial ! on the process of creating keycaps.
I’ve missed out a few pictures, but this covers the basics. Using a timer, it’s around half hour all-up per keyboard. Sometimes a little more if a print fails!
Tried to make a ‘GOLD’ keyboard but need to research a little on how to keep the particles suspended. This one failed due to too much gold. It all sunk to the bottom causing layers to become underexposed and ultimately sticking to the FEP
Also tried to make a crystal clear keyboard…unfortunately I topped up the vat with a tiny bit of the gold mix from a poorly labelled bottle I use f or mixing (I didn’t write any label!) I’ll give these away with a kit to the first person that asks 🙂
Quite late into development, I’d realised that the F keys were supposed to be a different colour. So, I add two sets of F keys to kits. Some early ones went out without the extras. Happy to send some out if you shout.