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

Showing some embedded Text

Side View

Lid

And, Printed – But a little too tight. New version is on the printer with an extra 0.5mm all roudn tolerance