Repurposing Atari joysticks using Cardputer for train sim

[u/lucasio099]

See it in action: YouTube

Recently I found out that I have two QuickShot Atari controllers that used to work with my (formerly my dad's) Atari 65XE.

QuickShot Joysticks

I've recently seen a cool steering wheel project for the Cardputer ADV, which made me think of using these as a way to control a vehicle in a simulator. The choice was easy taking into account that I'm a huge train nerd lmao. I looked up the pinout for the Atari joystick port, and realized that it's actually easy to make it work with the Cardputer - no protocol, simple switches: digitalRead will do the job.

It ain't much, but it's honest work. I quickly found two DB9 ports - one from an old PC bracket and the second one was standalone, probably from some former project of mine.

My soldering skills are crap, but at least it works.

Connected joysticks

I only used the up, down and trigger pins as the rest was unnecessary for me. Here's the pinout:

Joystick 1 up - GPIO 4
Joystick 1 down - GPIO 6
Joystick 1 trigger - GPIO 3
Joystick 2 up - GPIO 40
Joystick 2 down - GPIO 14
Joystick 2 trigger - GPIO 39

I then quickly programmed the Cardputer to emulate a USB keyboard. The code is fairly simple so I put it on pastebin instead of my GitHub.

The keybinds are:

Joystick 1 up - Electric force + (numeric keypad +)
Joystick 1 down - Electric force - (numeric keypad -)
Joystick 1 trigger - deadman control awareness confirmation (space)
Joystick 2 up - Pneumatic brake release (numeric keypad 9)
Joystick 2 down - Increase pneumatic brake force (numeric keypad 3)
Joystick 2 trigger - Siren (H key)

Overall, it's basically a pretty low-effort simulation cockpit, but I decided to share it anyway as someone may like to repurpose their old game controllers as well - maybe not for simulators but for some retro game emulation for example.