We recently noticed an open source design for TinyFPGA A-Series boards from [Luke Valenty]. The tiny boards measure 18 mm by 30.5 mm and are breadboard friendly. You can choose a board that holds a Lattice Mach XO2-256 or an XO2-1200, if you need the additional capacity.
The boards have the JTAG interface on the side pins and also on a top header that would be handy to plug in a JTAG dongle for programming. The tiny chips are much easier to work with when they are entombed in a breakout board like this. Bigger boards with LEDs and other I/O devices are good for learning, but they aren’t always good for integrating into a larger project. The TinyFPGA boards would easily work in a device you were prototyping or doing a small production run.
The files are on GitHub. According to the project’s main web site, this is the “A-series” because there are “B-series” boards forthcoming that use USB instead of JTAG, and will use the Lattice ICE FPGA devices.
The components on the board are 0603 and QFN32 packages. [Luke] suggests a solder stencil, paste, and an oven, but these size components are hand solderable, with practice.
If you want to look at the how and why of FPGAs, we covered another Lattice part in great detail, winding up with a PWM output device. Although the parts are subtly different, the work flow and principles will be the same. You’d just need the right JTAG dongle to do the programming.