for some reasons, when I connect both the pixy cam and Lego mindstorm to PC, the lego pixy block will not work (no data update) in most of the cases. Removing the USB cable from the pixy cam to the PC will solve the problem. If both could work at the same time, it will make debugging and developing much easier.
If you are running PixyMon on your PC or Mac and you plug Pixy into your computer via USB, PixyMon will switch to “cooked” mode. In “cooked” mode, you can see live video and you can see an overlay of detected objects. But in this mode, no data is being sent to your LEGO Brick. This might explain what you’re experiencing.
If you want to have Pixy plugged into your computer and run PixyMon AND have your LEGO program receive data from Pixy, you need to switch into “default” mode within PixyMon – click on the home icon. There is more information here:
Note, when you unplug Pixy from your PC’s USB port, or if you exit PixyMon, Pixy will automatically go back into default mode. Pixy changes to cooked mode when running PixyMon because it is a useful debugging mode. But you can disable the automatic switch to cooked mode by blanking out the “Pixy start command”:
Hope this helps!