Raspberry Pi Fallout Terminal PC -- Episode 373

I did have an idea for this. It’s pretty easy to interface with Wii controller peripherals like the nunchuck and classic controller, so I may do that.

Hi!

I grabbed the footprint for the switches off a site, componentsearchengine.com I believe. I could have sworn the solder mask was there when I was looking at it in Kicad. They’re definitely tiny parts, and soldering them myself seems pretty daunting. While I have soldered SMD before the parts were a lot bigger. It was a kit for learning how to hand-solder SMD parts, so very much easy mode in comparison.

The design checker passed, both on the schematic and the PCB. As for the routing, I did use an autorouter. I  wanted to see the ballpark of how much it’d cost me assembled. A bit prohibitive, especially if it turns out there’s some tiny error the design check missed out on.

All in all, I kinda feel like the startup and assembly costs almost make assembling it myself appealing. It won’t be perfect, but I’d have a bunch of boards to experiment with. I’d be using tweezers and tape to get the components in place.

thanks for the tips!

Hi James,

I've placed a graphic of it below, to make it easier to see. It *almost* fine to me, but make sure (if you have not already done so) to run the error rule checks and design rule checks in KiCAD. (I don't use KiCAD so I don't know how you access that, but it will have that capability). It's not recommended to send a design off for manufacture without doing that.

However, there's something strange going on with the switches. Are these created by yourself? They are missing the solder mask layer (in the graphic below, it should look pink like with the diodes). That's important to fix, otherwise the PCB will be unusable.

If this is your first PCB, are you sure you'll be able to solder the switches? They look extremely small, maybe less than 3mm long.

Also, the text (SW1, SW2, etc) is going to get wiped out by the PCB factory, in the areas where the pads are. The PCB will still function, but the printing will look ugly with chopped off text. To resolve that, either the text needs to be moved, or deleted. But this is a cosmetic thing.

The traces could be tidied up (I guess they are auto-routed) but appear functional, I did check the trace thickness and spacing you've got there.

If you want to do it cosmetically nice, then it all needs ripping up and manually drawn (for example, using the lower layer to do mainly horizontal traces, and the upper layer for mainly vertical traces). Here's an example (random picture via google) that is likely 2-layer too:

But in summary I think your layout will be fine, if you do the ERC/DRC, and also resolve the switch pads.

I started designing a keyboard in KiCad. I'm going to have to get creative with the key layout. This is my first attempt at this sort of thing, so I don't know if anything's wrong with the design. Right now this is just the layout for the keys and a pin header, with the idea that I'd attach a microcontroller to it and make it available as a USB keyboard.

Here are the gerber files

I added the abstracted version of the hacking game here https://github.com/skwirl42/robco-os , so those interested can take a look at the abstraction system and how I applied it in the case of the hacking game.

Also, I'd definitely need to get this assembled by whoever makes the PCB, as it'd all need to be small, SMT parts.

Thinking further on this, if I use small snap-dome switches and a silicone membrane I can fit a QWERTY keyboard into the space for the keyboard. Granted, the keys would be small, but it'd have decent tactile feedback and let me use the terminal fully.

And I can’t find the implementation of the hacking game that works inside my RobCo OS system, so I must just have it locally. I’ll figure that out at some point.

I’ll take some more pics of the case tomorrow, although there’s not much new there. I think I wrecked either the Pi or the on/off shim while soldering them together, since when I connect power absolutely nothing happens. My guess is the shim board didn’t take kindly to the rough treatment it got as I was trying to get it flush with the Pi’s pin header. My soldering skills are not great. I’m a software developer by trade. I’ve got a fork of the hacking game and I made a pull request to your repo for some of my changes.

When I realized that curses on Windows isn’t up to the task of properly displaying essential parts of the game I also started working on a platform abstraction to offer either curses or tcod as the display library. It also abstracts input, because I was considering having a gpio based input on the Pi, or just standard input if that’s not available.

So I guess there is more to show, it’s just not hardware.

This is the only decent shot I’ve got at the moment. The case still needs some sanding. It doesn’t show up very well in the photo, but the vent is a metallic grey. I also debated whether or not I should leave the washers on with the screws. And the Pi Zero is half visible there.

Another difference, I’ll be using a cobbler to break out the pins from the back of the display. I’ll still need to deal with the I2C pins that the speaker phat uses, but I believe the additional pins are brought out as pads on the back of the display.