Making your own printer with a Raspberry Pi
Making a printer with a Raspberry Pi is really easy, both in terms of hardware and software. Let's go!
Any version will do, as long as it has networking (so version B, through B+ and all the way to Raspberry Pi 3 and even the Raspberry Pi Zero if you've configured a wireless connection via USB...).
You'll also need an SD card of at least 1GB in size.
Of course! Our software works with the thermal printers available from Sparkfun, Adafruit and so on.
If you want to drive the Pi and the printer from the same power source, you need to ensure that you can supply enough current for both devices. I'd recommend at least 2 amps. The official power supply works great.
You need some way of connecting the printer to the Pi. If you're happy to solder, using something like the Humble Pi or the Pi Crust are good options; If you'd prefer to work on a breadboard, then something like the Pi Cobbler or the HT RPi Breakout Board Kit are good too.
There are two principle things we need to achieve: connecting the power supply for the printer, and connecting the data wires.
I strongly recommend you look at this pinout guide when figuring out which pin is which when making these connections!
Using the breadboard or shield, connect the power supply cables for the printer to the 5V (pin 2 or 4) and ground (pin 6) connections to the red and black wires of the printer power supply. If your Pi is powered on, you should see the green light on the front of your thermal printer start blinking every few seconds.
We need to connect the black wire from the data cable to ground as well; if you can't also connect it to pin 6, you can also use any of pins 9, 14, 20 & 25 (and others if you have a more recent Raspberry Pi board; check the pinout for details). Finally, we need to connect the printer's serial receive wire (yellow) to the serial transmit pin of the Pi (pin 8/BCM 14 in the diagram on http://pinout.xyz).
Latest instructions for installing the software are here.
If you've already got a linux image you're happy with on an SD card, you can skip everything except ensuring that the right ruby packages and gems are installed.