Analog Discovery 2 digital input failure?

[decibell]

I recently purchased an Analog Discovery 2.  I was hooked up to a circuit using the breakout cable on the other side of the BND board to do some testing on an SPI bus using the digital inputs.  I got some data but I didn't get far enough to verify all that i needed.  I disassembled the circuit and identically reassembled the next day, and it appeared none of the digital inputs were functioning any more.  I verified the pins of the circuit being tested were active with the oscilloscope.  I also used the waveform generator to generated test input but all inputs tested would not show any signal coming in.  I also reinstalled both software packages and rebooted the host system.  Are there any other possibilities for why this would stop working?

[attila]

Hi @decibell

It would be better to test the DIOs with signal generated on one channel and looped back on another one, Static IO or Patterns and Logic instruments. With AWG make sure you set sufficient offset and amplitude to cross the ~1.5V digital input logic threshold, like 1.5V offset and amplitude.
Did you had proper grounding between the device and circuit under test? This should be the first connected and last disconnected. Without common grounding it could be high voltage differences between the units that could damage those.