A500 Mini Keyboard – D’oh! More work needed

Nah, that looks crap.

Well, that’s a wrap for idea 1 – concept was ok enough, but…it’s no-where near good enough for a production run.

After half a dozen trial prints and practice fittings, I’m heading down another path.

The Many faults include

Keys fitting poorly to switches.

Keys not fitting on switches straight

Keys just not fitting onto switches at all

The attached picture sums it up really.

All is not lost however. This is something I had to trial, if it worked, it would have been cheaper and awesome.

I have a few ideas up my sleeve…My next option is right now, considerably more expensive, but has been underway for a few weeks now, I’ll reveal a bit more once the process is done.

On the plus side, the keycaps look great in Amiga Beige! – I’ll work on the darker caps another time.

The PCB layout works great, firmware works, so, really, it’s down to the thing that always was going to be an issue, the switches!

Dodgy Laptop Hinges – Lenovo Ideapad 5 15″Model 15ARE05

Nearly two years ago, I purchased a rather nice laptop – https://www.lenovo.com/gb/en/laptops/ideapad/500-series/IdeaPad-5-15ARE05/p/88IPS501393

A Nice Lenovo 15″ beastie, with a Ryzen 4800U

I blogged a bit about it right – HERE

Just after Christmas, one of the screen hinges snapped – I had a quick google, then really did nothing – I found thhis bloke –

It’s Binh Repaired & Reviewed

and, this video

https://www.youtube.com/watch?v=jQ3YShJosio

and, as the laptop was functioning ok-ish, I dismissed it – it was robust enough to use, and wasn’t properly broken….

…Until it was –

A couple of weeks ago, both hinges just failed, leaving my laptop screen ‘dangling’

So, I googled again, discovered that I’m not alone. Most people seem to jab a bit of JBweld in and hope for the best

https://forums.lenovo.com/t5/General-Discussion/Broken-Hinge-on-IdeaPad-5-15IIL05-Laptop-Type-81YK/m-p/5063546?page=4

https://www.bogleheads.org/forum/viewtopic.php?t=369644

I didn’t have any JBweld.

I Did however have the following items, which, after years of desperately needing a project to justify the purchase have Finally come in useful and saved some cash

Ingredients

……. a Portable Dremel thingy,

a wide collection of tiny drill bits

boxes of tiny screws and nuts.

A ridiculously small adjustable spanner on my car keys

My laptop no longer has a non-functional Hinge

Have a small Montage of pictures

To Be fair to Lenevo – they’re extremely responsive for customer support. I can not fault their technical team, nor their customer support team, pro-active calls, checkups and emails, all in, a 5* Lenovo response…..

with one caveat, My laptop’s out of warranty. Still, for most, a quick hundred quid ain’t too bad a price to fix a £500 laptop properly!

A500 Mini – part 8 – partly working keycaps and a small PCB reveal

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 🙂

Another failure
Another failure!

And, the reveal, part 2

It’s here!!!!

A500 Mini II Part 7 – other ‘stuff’

Along the way, I’ve been tweaking some other bits – The Real miniature fake USB Floppy disc is progressing nicely

IT FITS!!

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!

A Floppy fits in the drive!
Tiny

The silver ‘label’

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!

A500 Mini II Part 6 – past the half way mark! – keycaps

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.

Tops not parallel with bottoms
Tops are parallel with bottoms
Continue reading “A500 Mini II Part 6 – past the half way mark! – keycaps”

A500 Mini Keyboardification Chapter two, part 4 – Moar CAD

Have been tweaking things over and over, I’m now finally ready to…….

3D Print a sample!
And, the complete thing

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

Alternate View – with the Clamp PCB in black, the A500Mini PCB in green

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!

A500 Mini Keyboardification Chapter two, part 3 – PCB’s

I’ve spent a couple of days designing, and and a today, spent nearly a hundred quid at JLCPCB ordering a bunch of prototypes

The first revision of the Keyboard PCB
First ‘space sample’ of the top mounting board.
Floppy Disc Micro SD card holder!
Rear of the floppy discc.

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!

A500 Mini Keyboardification Chapter two, part 2 – Progress

This one’s a good ‘un

Progress to date has been surprisingly quick – most of the ‘easy’ stuff is now done and I’ve added some extra functionality. Most of the research is now done – have spent waaaaay too long googling connectors, Pogo pins and component types / dimensions.

First print of the keyboard PCB and CAD fitout – pretty close

My workflow generally is to eyeball, sketch, measure, adjust….Then when it’s close enough, i’ll print on paper, adjust in CAD, print again then………3D print

a 3D printed space sample

I’m quite chuffed – the first 3D print seems to fit reasonably well! – there’s some adjustments needed, mainly the top of the keycaps are a little too wide, but overall for a first run, not bad.

The PCB outline

To work out a PCB outline, I’ve scanned the A500 Mini on a flatbed scanner and trace around the important parts, measuring many with calipers

the Keycap CAD
Another view – the big circles are the curves / slight indents in the top of the kecays
The CAD compared to a scan of the actual A500 Mini

Before I 3D printed the sample, I put the A500Mini on a flatbed scanner to match up the holes – as you can see, it’s pretty darn close! – you’re seeing a canvas underneath the actual CAD model of the keycaps in Fusion. The Enter key is black as i’d discovered a slight profile error, so spent half hour correcting a 0.2mm height error 😛

But, wait, there’s TWO

During the design phase, there’s a process of discovery. My main discovery for the A500Mini keyboard was that….I’d possibly need TWO PCB’s!!

If you look above at the underside of the keyboard you’ll see that there’s no space on the top for electronic components! The PCB needs to mount entirely flush to the case of the Mini. This means I’d need a PCB assembly service that can handle double sided boards (a possibility) – And to also consider a two PCB solution. There’s cost and ease of install considerations for both ways.

The A500Mini has a number of test points on the back, I think using Pogo Pins I can maybe make a clip-on PCB that can securely tap off the USB test points, meaning, a solderless install! – hence the upper white PCB that sits in place of the A500 PCB above

And, now I believe I’m going to go with a THREE PCB solution…….because…

the one with the holes in sits above the stock PCB

That’s a scale floppy disc! with a Micro SD card in
quick render of the floppy slot in the case

I saw a few posts on facebook linking to a guy that’s made a ‘fake’ floppy insert for the A500Mini – https://www.printables.com/model/170947-amiga-500-mini-a500-mini-mini-floppy-disk?fbclid=IwAR3if5FRp3opclhKoTyrkUe63XQtRW-mckg2ymWSKKi1cZvSk1KuRRkzmR4

I figured I’d go one better and make a REAL fake floppy disc. and, the best thing, after several solid days of research and CAD testing, I believe it can work 🙂 – it’ll only need two small cuts inside the A500 case and be totally stock outside. there’s a little more tweaking needed for the floppy disc design to make the MicroSD slot more elegant . I’ve ordered a whole bunch of parts to physically trial this and see if it’s viable.

So, Summary. Still a long way to go, the Keyboard itself is the priority here, the ‘floppy disc’ is just a whimsy on my part for the time being, its development is secondary and may not even make it to a real release if it’s not robust enough.

Keycap CAD – Cosmetics finished, Just needs the ‘switch’ solution figured out

Main PCB – Outline finished, needs routing, quick job to finish

Secondary PCB – Outline finished, needs routing and Pogo Pin solution testing

Tertiary PCB for the floppy disc connector – Concept – parts ordered

Fourth + Fifth PCB’s – the floppy disc itself – parts ordered.

Firmware – Standard keyboard layout is done! – Just needs tweaking and testing on a real A500 Mini

A500 Mini Keyboardification Chapter two, part 1…The Evisceration and Dimensionality

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!

Dimensioned to within about 0.3mm

Spmeone should hide my screwdrivers

A500Mini keyboardification – alternate technology

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

In other progress – the A500Mini Manual is now available – and, the Keymap is shockingly simple 🙂

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!

A500Minier (than 50%)

All along, I’ve been assuming the A500Mini will be the same 50% scale that the C64Mini is

Thanks to https://youtu.be/h552-eR0cGA Retro Recipies

And https://youtu.be/igEpW8QJFQ4 8abit guy

I’ve been able to get an idea of the size of the A500mini

A500Mini

Using the USB socket size to scale, they’re about 13.2mm in real life.

We get about 186mm for the keyboard width.

The real A500 has a keyboard cutout width of about 450mm

186/450 = about 41.3%

So, summary, it’s closer to 40% scale than 50%

And, I gotta figure out a whole new way of keyboardification:-p darn you rascals at Retrogames LTD :-p

A500Mini Keyboardification – Part 6 or 7 I think

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!

CR-Scan 01 – cheap 3D scanner

Only a quick one – I backed this thingy

Have followed it for a while before the public launch and I’m damned impressed with the quality of the scans at the price.

There’s a load of YouTube videos showing independent reviews and capabilities of the device, which has me extremely reassured

I’m gonna use it to scan the children in and create custom Heroquest miniatures!

Gonna try scanning a room, maybe a car, who knows what else 🙂 . it’s not designed for scanning 28mm miniatures, but a few people have videos up on youtube that suggests it can give a low detail scan ideal for a ‘starter’ form to add your own custom detail – which makes me very happy as i’m crap at organic modelling 🙂 also, now whilst I type, I realise I can scan KEYBOARDS in! – it’s detailed enough to get those pesky curves correct and allow me to model properly the C64 keyboard!! wooooo.

For a while I really wanted to upgrade my ancient iPhone 5SE to one that has lidar / time of flight sensors on board (iPhone 11 plus or higher) But the quality those devices produce is mediocre compared to dedicated scanners.

Don’t get me wrong, the iPhone ones are a massive enabler for all sorts of fantastic 3D mapping (caves!! It’s a paradigm shift in capabilities and accessibility, that’s just one example)

Put simply, cube capabilities of this scanner (and software package) exceed anything available at the price, and quite a lot available at the 4 digits in price.

So, if you’ve ever fancied scanning stuff and can’t be bothered with photogrammetry , get this!

Generic link below, zero referral or cash back from this link 🙂 I’m just that impressed with the company openness on this one, check the comments if you’re unsure! and the number of updates

https://www.kickstarter.com/projects/3dprintmill/creality-cr-scan-lizard-capturing-fine-details-of-view

More A500 Mini

Working on the Fonts now for the keycaps!

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”

https://deskthority.net/wiki/Amiga_key

and, the Font – is Garamond-Bold-Italic

So, now we have the following two keys!

and, extruding that A to create a solid A, then projecting to a sketch, offsetting that sketch and extruding into the key….

we have…The other Amiga Key!

Now to figure out the rest of the keyboard 🙂

A500 Mini Part 6

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

simple hidden edges image
Nice render on a snowfield to show the curves

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.

A500 Mini Keyboard Part 5

Small updates – keyboard keycaps progress!

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.

One key from each row complete!

Moar Heroquest

Decided to try to knock up a set of alchemists scales!

These bits often get broken. Quick half hour in Fusion getting the first eyeballed set done, then another hour ‘fixing’ the model once someone gave me the correct dimensions. I’m getting someone to check out the model , comparing it to the original, i’ll then put it up on Cults or MyMiniFactory

Something a little different – V-Bucks

My Son asked could he have some V-Bucks for that ridiculously addictive Fortnite – it’s totally free to play, but to be ‘cool’ you’ve gotta spend real life ££ on skins . As he’s done quite well at school, I’ve decided to reward him with some, but rather than just hand over a string of characters on some paper, I’ve spent a little more time being creative

If you fancy playing with this yourself or editing it – I’ve uploaded the Fusion360 f3d file to Google Drive – Here

And, also the STL files to Prusaprinters – Here

It’s all eyeballed, but seems close enough to the original. It’s quite a simple item to do, the hardest part to figure out is the tapered top of the coin – which is a simple ‘side profile’ then revolve to create the coin. The rest is a circular pattern to create the curved lit up pieces, then a handful of extrudes and fillets

A500 Mini – Quatre

First ‘proper’ spacing test for the SMT switches

First Proper scale PCB layout for the A500 Mini. it mostly looks like it’ll work – BUT, there’s some problems.

I’ve highlighted the problematic switches with white blocks

The Problem – Having switches at 0 degrees or 90 degrees means at some point, due to the staggered keyboard, some will overlap. I’ve spent a few hours optimising the rotation of the switches to reduce the number of overlaps to a minimum, AND, to give all those overlaps a common ‘thing’ that possibly provides one way of easily fixing this.

Zoomed in view

I’ve made it so that Every ‘overlapping’ switch has the bottom left pad causing the overlap. This means, with the right switch type, I can simply cut off this leg for each of the 8 problematic switches and have the keyboard work just fine!

In Most SMT switches this size, there’s 4 legs, but often only 2 are used, (single pole) or sometimes there’s 2 separate switches inside (double pole). provided I use the correct two pins, they should just work fine with 3 legs soldered in. This isn’t exactly an industrially abused keyboard, so 3 legs is plenty of mechanical support.

BUT – I’m unsure if I could ever convince a PCB assembly house to cut a leg off the switches and solder them at a reasonable price, meaning that I may need to solder these 8 manually myself.

There’s a potential other fix also – Rotating the switches at ‘odd’ angles!

If you squint closely, there’s now no overlapping pads on the switches, However, this comes with potential issues

1 – Manufacturing, companies may not want, or be able to put switches on the PCB at arbitary angles like this

2 -Available space within the A500 Mini is currently unknown, which may not give me enough height to be able to do this.

Physically, a 6mm switch, placed at 45 degrees ‘just’ fits within the available 9mm envelope for each 50% scale switch

Rotate that square and you get a circle – which is less than 9mm, which is less than the keycap size!

What this means –

If I rotate the switch, I will not be able to have a recess on the keycaps. On the C64Mini, to keep the keyboard profile height correct, the switches sit about 1.5mm into the keycaps when pressed down. Without this recess, the new keys may need to sit higher than they should. But, this depends on how much space is available underneath the fake keyboard in the mini – it should be possible to add some spacers in to bring the height back down.

The switches sit inside the keycap on the C64Mini keyboard kit

So, The big summary is, Right now, there’s no roadblocks to making this work. a Fully automated production is preferable to bring costs down, so i’ll keep working down that route.

Things to do –

Contact PCB manufacturers to figure out manufacturability

Everything else!

A500 Mini Keyboardification – Part III

Early days – Square keycaps to create a layout grid in EasyEDA

A little more advanced

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..

Voila, a 100% sized Amiga keyboard outline imported 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.

As for Software – PRK has had some great updates of late. I’ll be figuring that out soon enough

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!!

A500 Mini Keyboardification – Part Deux

Maybe a 2 part kit for the Amiga Mini?

Minor update! – Slowly working on the PCB design for the Amiga Mini – I’m tempted to actually produce a few of these as a Beta run so I can get ahead on the keyboard matrix programming.

I’ve priced up on https://jlcpcb.com/parts/ a BOM to build a minimalist Pi pico so that I can place one directly on the keyboard – and surprise, just like the Arduino Pro Micro device – The sum of the components is more expensive than the price of a full Pi Pico ! BUT, and key point, it’s not all that much more. building Arduinos out of components were typically around DOUBLE the cost. The Pi Pico isn’t!.

However, adding a RP2040 discreet chip to my PCB adds a small level of additional complexity to the board and puts me at risk of parts going out of stock so it’ll be a weigh up when the real Amiga mini is released – If there’s enough space on-board to make a 2 layer board, I may well do this. If not – well, that’s what the TWO circuit boards above are.

Early days yet, but first look suggests that the above would be only marginally cheaper (almost not worth it) than putting a discreet pi pico on-board

oh, and of course, these will be fully populated boards! just add keycaps and ‘go’

Resin Printing and cold temperatures don’t mix. Making a heater!

After having a few failures over the past few months, i’ve tried a number of things to increase the print success rate.

The biggest improvement came from temporarily moving the printers out of the cold conservatory and into the much warmer living room.

That’s a bad thing to do on a full time basis as resin fumes ARE toxic .

There’s a whole slew of ways of heating up the printer. People have heated their rooms (expensive). Put the resin printer on a heated printer bed! (genius, and works). They’ve also cobbled together a bunch ‘o bits and made a heater. Probably the most elegant one i’ve seen is by Elegoo!

So, what does a person do when there’s pretty much a slew of commercially available suitable heaters for a 3D printer………

Yep, you go and roll your own!

I worry that the commercial ones may be too powerful I only need to raise the temperature around 10-15 degrees above ambient. Having seen friends use 50watt lamps in vivariums of much larger volume than my printers, I’ve figured a 50 Watt dedicated heater device should be more than enough….

So

I’m going with a https://hobbycomponents.com/sensors/684-w1209-temperature-control-switch W1209 Temperature control device and sensor

(thankyou to https://www.thingiverse.com/thing:3442165 for the inspiration for the product and also this Hackaday Article

a 50 Watt PTC Heater 12V DC https://www.amazon.co.uk/gp/product/B07SC15TK7/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

(thankyou to the Elegoo heater thingy for this decision)

and a 60mm Fan https://www.amazon.co.uk/gp/product/B07HCGZ5FZ/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Thank ME for this one – I purchased 5 off 80mm Artic F8 case fans back in March last year for an absolute steal. With the intention of upgrading cooling on the Wanhao D9 and in anticipation of designing a small heater for the resin printers. I can’t find them, so, this pair was about the best deal I could find for quick delivery

This lot cost me about £20 in total – Not bad considering it’ll be twice as ugly as the £10 commercial units, which, at £10 will be delivered in March, which co-incidentally is about the same date that i’ll likley finish assembling this monstosity!, D’oh!

ah well……..

Now, All I need to do is create some sort of 3D printed enclosure to house ’em all, figure out how to route cables and voila, i’ll have a nice ‘thingy’

Note, this lot can be gotten for easily around a tenner total, if your patient. However, It’s cold NOW, so i can’t wait a few months for delivery (when, in the UK it’ll still be cold, just a bit less cold)

Amiga 500 Mini – conceptual

1/2 scale Amiga Keyboard – the keys might just fit!
Schematic with who knows how many errors 😛

Had a little play, using some SMT buttons i’m using in another project. These switches aren’t quite correct for this project – I need ‘square’ button-y bits and preferably ones with a small sticky-outy or inny bit that’ll let it capture a keycap straight.

Assuming the A500 Mini is 1/2 scale, like the C64Mini was then it’s looking good for keyboardification.

This keyboard is about 225mm x 56mm which is about 1/2 the size of the original membrane – I ‘think’ – based losely on numbers from here which says

Full sized Amiga is about 470mm wide by 325 deep.

Half that gives about 235 x 162. take a bit off the 235 for the case thickness bit – gives 225. then height is set roughly by the number of keys ‘down’ and eyeballing the various membranes i’ve found!

However – I don’t know the internal space availability of the A500 yet – so plan going forward for now is to prototype as a 2 part PCB.

One design part of the C64 Mini keyboard kit I never really liked is the standalone Arduino Pro Micro mounted on the rear due to being no space. Adding it to the main PCB was also out of the question as the separate components would have been at least double that of a ‘cheap’ arduino.

I’ll keep a 31 way (ish) connector on the main keyboard part, so it essentially acts like a traditional Amiga Keyboard. I’ll then have a ‘special’ RP2040 based PCB that converts the Amiga matrix into USB for the A500.

Amiga 500 Mini – Keyboardifying

Very early days yet – But, this is the first start for making the Commodore Amiga Mini working keyboard kit! About 1/2 way done on the matrix, then the peripheral components to go.

Then i’ll ditch it all and start over as the above is a bit of a mess ;-P

The New mini is coming from https://retrogames.biz/thea500-mini at some point in the next few months

I plan to use PRK Firmware now i’ve got it working with the C64Mini

and, Now RP2040 AKA Raspberry Pi Pico Chips are widely available, and ‘cheap’, I’ll be using one as the basis for the Mini

The BIG unknown right now is ‘switches’ – in the C64 Mini I was able to use 5.8mm ‘square’ switches – something like these – https://www.sunrom.com/p/push-onoff-switch-58mm

I’m currently working on a design assuming I can use the same again. There’s very few switches on the market with a ‘square’ style centre part that can capture keycaps. I have leads on a few others, but plan this time is to find surface mount versions and try to get a batch ‘mass produced’ – i.e. little to no soldering needed for you lot!

Early days yet, it’s been quite hard to ‘get back into the grove’ . here’s hoping I get this finished in 2022!

Anycubic Photon Mono-X 90 Degree dripper

Very early days yet on this design. A couple of hours of measuring and sketching in Fusion360. Needs some finessing, but the principle is sound.

Given 90% of my printed things are quite short, (keyboards, Mini computer case prototypes and miniature monsters) I can comfortably make a very efficient 90 Degree bed resin drip drainer and keep the cover on!

Most drainers are maybe 20-40 degrees or so!

The new Drainer bracket in Yellow – Sits permanently on the printer
And, the position of the bed when it’s rotated 90 Degrees. The Yellow bracket and the original ‘stick out bed holder’ clamp the bed sideways between then! The ‘curve’ bit stops the bed sliding too much to the right and ‘off’.

Heroquest Cards Holder

Got a little hooked on playing Fortnite This past few weeks! who’d have thought that Battle Royale would be fun to play! – just like the old days playing Multi player LAN Doom and Duke Nukem, except even better!

Have finally stopped procrastinating and becoming a little more creative. A friend in the Facebook group Heroquest Printed Knocked up a full set of Sjeng Heroquest cards for me. This goes well with the Hendar23 Book of quests and provides many more extra cards to make the game a little more interesting!

Complete Box

Success is in sight – keycaps

First print off the Mono-x

I’m having first layer adhesion issues – which is commonly caused by poor levelling on these things

Could also be a number of other issues but I’m confident I can get this resolved next week

The major fault on this one is that the bottom row of keys is all squished going to the right hand side, due to that side not adhering to the build plate correctly.

Have had another print literally just finish – with adjustments and that’s also come off the build plate so I’m really confident that I just need to try re-levelling again!

Delays in keycap printing – and progress

RERF TEST

Apolgies for any delays and people waiting on keycaps….

I believe I may have reached the end of life of my original Photon Mono printer. for the past couple of months, i’ve been having more and more print failures, and have had no idea why. I’ve approached the problem analytically to figure out what’s wrong

Where it started –

I had a proper working file that ‘just worked’ – exposure about 35s for the first layers and about 1.8s per other layer

That started failing a bit. some keys were printing incomplete. I increased the exposure slightly and success again.

More fails, this time the first layers were coming off the build plate. I increased the exposure for the first 4 layers and success again.

had many minor creeps of fails, up to now where i’m at around 50s for the first layers exposure and 2.2s per layer.

I figured maybe the temperature in the conservatory is too low – Nope, iterating a bunch of exposures with the printer near the radiator in the living room also had nothing but failures.

So, after a good 15 fails in a row, many caused my me experimenting with extremes, i’ve given up with the photon mono. There’s many things it could be, but I’m thinking it’s feasible that the LCD has finally ‘failed’. I’ve easily gotten 1500 hours of actual print time on the thing – well over 1000 will be just the production keycaps at 6.5 hours each!

So, back to the point of the article. Those things in the picture are a R E R F TEST for my Anycubic Photon Mono-X

I’m dialling it in to start printing the keycaps. First one’s going right now (50% UV power, 3.5 seconds exposure and 45s base layer if you like to know)

IF this keyboard prints – fantastic, I can print two at a time in just 5 hours! i’ll be through the backlog in no time 🙂

Thanks for listening and sorry again for the delays!

Dean