I2cdetect fails to find any downstream sensors on PR19-7


I recently purchased a PR19-7 shield for my Raspberry Pi Zero W as well as a PR2C-6 gas detector.
When I connect them to my Pi, I find no visible devices on i2cdetect -y 1.

I do have some other i2c devices that I am able to test with, and when I use an Adafruit Stemma-QT shim with a GPS unit, I do see that device correctly detected on i2cdetect -y 1. Further, I tested by adding this Stemma-QT detector to the pass-through on my PR19-7 and found that when I use the pass-through no devices are detected on i2cdetect -y 1.

My belief, in particular based on the similarity to this user’s issue, is that my PR19-7 shield is defective and is corrupting everything connected to the bus.

Is that a fair assessment or is there something else I should try?


I tested it in another Raspberry Pi (B+) with the same result. i2cdetect -y 1 finds no devices.

Can you provide a photo of your hardware setup showing the PR2C-6 connected to the Pi?


I returned these products as defective.