I bought an antique telegraph sounder a while back, and I’ve been working on a project that will click out emails from my Etsy store when I get an order. I’ve gone through several generations, and come up with something I really like. What follows is a description of my process for going from concept to finished piece. The code & PCB are open-source, and can be found on my github.
When setting up a new Raspberry Pi, it’s helpful to have console access, which could mean hooking up a screen and keyboard to the pi. Another option is to connect your pi to your computer with a USB cable, and connect to the serial console (similar to connecting via SSH or telnet). You need a special cable, but it saves you from having to keep a monitor and keyboard just for the pi.