I’ve made a test instrument that does tasks you’d commonly need when testing a microcontroller-based project, and makes them as quick and easy as a multimeter. I call it a Logic Meter.
I made this as a hobby project. I would love to see someone take this design, or at least this idea, and turn it into a commercial product. And so I have posted the schematic, board layout, and source code at https://github.com/galacticstudios/Logic-Meter.
If you do start making these, please let me know! I would love to buy one from you.
It uses a multimeter-like UI for ease of use. Its features include a UART monitor (with auto baud detect), an SPI monitor, a UART source of canned data (which you can download to the multimeter), a servo pulse generator, a PWM generator, a GPS simulator (you can generate NMEA sentences for any location and time), and a low-end logic analyzer.
Here’s a demo:
