After uploading the latest firmware, Pixy2 does not work and shows the error: unable to connect to device or unplugged. Before uploading, everything is right.
Did you choose the correct version of the firmware? There is a general and a LEGO version, and both links are beside each other on the website. It is plausible the wrong one was clicked inadvertently.
Using the wrong version for your controller type produces the no response error because the communication protocols are not properly configured.