StackOverflow "best practice when unit testing for embedded development" - “A necessary tool to develop is a signal injector. The embedded system will have some way of interfacing with a host system (typically via a serial port reserved for debugging). Use this to send test data (best option is terse ascii formatted so it is easily simulated by humans too)”, “Using TeraTerm as a serial port signal injector, and writing some TeraTerm macros (takes about 20 minutes), there is a huge suite of automated tests which can be run against any part of an embedded system – whether driver layer, O/S, layer 4-5, etc”.