I'm on the hunt for a logic analyzer to debug digital protocols. I plan to use it to debug high speed SPI busses (up to 50-80MHz) and USB 2.0 FS (I want to write my own USB stack for a STM32 as a learning experience). My eye is particularly drawn to the Digital Discovery, as for the price it has very high sample rate. I still have to buy a LA though, as I'm still scouting around what works best for me.
Therefore, I installed the Waveforms software as a demo, but did not find the USB protocol in there. Obviously it would be complex to write a custom decoder while simultaneously also writin