I have a bus pirate, and it is sitting on the shelf most of the time. For serial, I end up using dedicated adapters. Terminal for text, custom python script fo

I have a bus pirate, and it is sitting on the shelf most of the time. For serial, I end up using dedicated adapters. Terminal for text, custom python script for binary protocols. For I2C, I have some USB dongles which appear as /dev/i2c-* devices. Use bash + i2c-tools to debug, then switch to python for more complex stuff. For unusual protocols, I can use Arduino(clone) directly. Sometimes this needs a trivial interactive handler, like '2' to toggle CS2 line and 'x' to shift in 5 bits. The problem with BusPirate is that you are not going to integrate it into your device, so whatever scripts you write to it will need to be rewritten for "real" thing. And its interactive mode is pretty limited and you grow out of it very quickly.