Raspberry Pi Pico MIDI controller with SamplerBox 2019 image PiZero

Hello rajivdeo,
First to verify I understand correctly: you connect the PiPico with its USB to samplerbox. Because of the circuitpython package it should be recognized as a midi device.
Does it derive its power from that same usb interface (=from samplerbox) ?
If my understanding is correct, then thanks for this interesting tip!
Now for your question:

• Please use the latest=20200810 image from the Downloads page
  
• Debugging is explained in debugging paragraph on the Build page
  
• It may also be useful to download renewed midimon.py in the download area.
  

The console log of samplerbox start and/or midimon output should give some leads.

Regards, Hans