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Another "Pixy2 not detected in linux" issue


I am using a NanoPC-T4 running Linux (specifically Ubuntu 18.04.1 LTS). I have downloaded all pixy2 software and have successfully built all the utilities as well as Pixymon, and have copied the permissions file to /etc/udev/rules.d. After plugging in the pixy2, the lsusb command shows the appropriate entry as indicated in the wiki. The issues I describe here occur with two different cameras, both of which work fine when plugged in under Windows. I have installed the latest firmware on the cameras.

When on the linux system, I have tried plugging them in a USB 3.0, USB 2.0 and a powered hub (to eliminate any power related issues) but the problem remains, which is simply that the camera is not detected.

Specifically, when I run (using sudo) the various utilities (such as get_blocks_cpp_demo) I get an error “pixy.init() returned -3”.

I have also fully built Pixymon and when I run it (with sudo and without sudo) I get a similar situation, but the status bar message at the bottom reads “Unable to connect to device”.

I noticed that if I leave Pixymon running and unplug the camera, the status bar reads “Unable to open USB device” but once I plug in the camera, the message changes to “Unable to connect to device”. The program seems to go through a cycle where the GUI elements temporarily became enabled and then disabled. If I enable the console window, the message shows:

Pixy detected.
error: Unable to connect to device.

The “About” menu brings up more information in the textbox:

PixyMon v2 version 3.0.24
Pixy2 firmware version 1.0.0 build (queried)
Pixy2 hardware version 0.0 (queried)

I have seen at least one other person post a more or less identical issue and wanted to add my issue as it doesn’t seem to be an isolated incident. Any help would be greatly appreciated.


Sorry for the problems and thanks for the information. These kinds of issues are difficult to debug remotely. Would you be willing to loan us your platform for us to take a look?



I can definitely make arrangements to do that, but our ultimate goal is to have 4 pixy cameras on our robot so we can track objects around us. I had not gotten to that point yet, but is the ability to connect to multiple cameras (and identify which one is which) part of the library? If that is the case, I can commit some resources to have a system sent to you for testing.


Yes, this should be possible. If you want to hook multiple Pixys to your host controller, SPI, I2C and USB will work for this. But I assume you are going to use USB to communicate with your Pixys.

Someone will contact you via email…