New drop-in replacement mechanical keyboard for the Atari 800

[Panther]

5 hours ago, ScreamingAtTheRadio said:

Well, there's room on the PCB... If your experiment works, I wouldn't be hostile to bumping up the BOM a few tens of cents and add one of the surface mounted versions. The main drawback for me would be that it would add a short programming step to assembling the keyboards...

Plenty of room.  Once I get some other stuff taken care of around here I plan to add one to the extra board I assembled with my spare keyswitches.  I already added the MCU and MOSFET to the schematic, and I have the ATtiny13A and TO-220 in stock.  Yes, that is a drawback, I hope you have an SOIC-8 socket for your programmer.  😁

 

[Panther]

Dialing in the PWM.  I've not connected the keys yet for control, that's next.

 

[Panther]

In progress.  This isn't actually doing key scanning yet, but the LED control does work, and I plan to add some special functions.

 

[Panther]

Oh, and ignore my Frankenstein keyboard layout with the mix of keycaps from Windows keyboards.  I didn't purchase any extra sets of the ASDW Keyboards keycaps.

 

[Panther]

Working out the signaling from which the MCU needs to capture the keypresses...

 

[Panther]

There were a couple issues I encountered when installing the keyboard...

 

The front keys were hitting the edge of the case, just barely, but enough to make a clunk and interfere with usage.

 

The keyboard just didn't fit back any further due to the plastic tabs in front of the door latch.

 

I had to put small notches in these.

 

Which resolved that issue.

 

Here is with the mounts installed:

 

However, one of the mounts interfered with the reset key.

 

Shaving down the edge of the mount fixed this.

 

These were minor easy fixes and the keyboard looks and works great.

 

[_The Doctor__]

I would have notched the PCB and not weakened or damaged the Atari case in that area as it is already stressed and prone to deformation

[Panther]

37 minutes ago, _The Doctor__ said:

I would have notched the PCB and not weakened or damaged the Atari case in that area as it is already stressed and prone to deformation

Some people have strokes over the thought of even scratching the Atari, but at least in this case the stressed area are those pegs against the spring bar, not the tabs I cut into.  Nothing to deform there.  Notching the PCB is certainly an option though, there's nothing close to the edge.  I'll consider that next time.

 

[ScreamingAtTheRadio]

@Panther, that's strange, I had none of these issues, but I went ahead and made the following modifications to the design for the next revision:

I'll push those changes to the repo shortly.

 

I also noticed one of the four mounts is incorrectly oriented on your photos, you might want to unscrew it and rotate it so it fits better.

 

[Panther]

3 hours ago, ScreamingAtTheRadio said:

@Panther, that's strange, I had none of these issues, but I went ahead and made the following modifications to the design for the next revision:

 

I'll push those changes to the repo shortly.

 

I also noticed one of the four mounts is incorrectly oriented on your photos, you might want to unscrew it and rotate it so it fits better.

 

There are probably slight differences is various XE revisions.  These changes look like they'll do great.  I'll print some of the mounts soon and test.

I had been mounting and unmounting the keyboard repeatedly and just didn't have one lined up quite right for that photo, but I did get them all on correctly.

Thank you.

 

Meanwhile, I started writing the code for detecting keypresses with a keyboard connected to an Atari and will work on getting that part of it tested this week.

 

[malachykidd]

On 6/29/2024 at 10:57 PM, ScreamingAtTheRadio said:

This is open source like all my designs, so you can build your own

 

Danke!  Am I correct that you use the PCBWay plug-in for KiCAD to submit the Gerber files to them for production?  Are there any PCB or assembly settings which must-- or that you recommend-- be changed from defaults?  The color of the solder mask would seem to be a given.

 

For the metal backplate, it looks like that's just a PCB as well, but I'm guessing the material is set to "Aluminum."  Is that right?  Anything else which deviates from the defaults?

 

Thank you!

[ScreamingAtTheRadio]

3 minutes ago, malachykidd said:

Danke!  Am I correct that you use the PCBWay plug-in for KiCAD to submit the Gerber files to them for production?  Are there any PCB or assembly settings which must-- or that you recommend-- be changed from defaults?  The color of the solder mask would seem to be a given.

 

For the metal backplate, it looks like that's just a PCB as well, but I'm guessing the material is set to "Aluminum."  Is that right?  Anything else which deviates from the defaults?

No, I use this plug-in: tobsec/JLC-Plugin-for-KiCad: Fabrication Toolkit - An JLC PCB Plugin for KiCad (github.com)

 

I just use the defaults at JLCPCB, except for the color, which I set to black.

 

The metal plate is an aluminum PCB. The black color for those costs extra $$ but is worth it, you want the plate to be as invisible as possible under the caps.

 

All details in the project's readme: 3d-junkyard/DecentXE/readme.md at main · bleroy/3d-junkyard (github.com)

[malachykidd]

20 minutes ago, ScreamingAtTheRadio said:

All details in the project's readme: 3d-junkyard/DecentXE/readme.md at main · bleroy/3d-junkyard (github.com)

Ah, great.  I downloaded the entire GitHub archive, but I fixated on just the Decent 800 stuff-- the DecentXE readme includes some valuable info that I don't remember seeing in the 800 readme.

 

Again, thank you.