Testing px4flow I2C1 bus

My px4flow worked wonderfully for a long time, I could send the i2c address 0x00 and receive the data frame just fine up until today. Now when I run i2cdetect from my micro controller, the px4flow (0x42) is not detected and I cannot retrieve data from the camera.

I reinstalled the firmware using QGroundControl and checked the camera and everything looks ok. The orange LED labeled COM is active, but i2c bus seems non functional. The voltage of SCL and SDA are around 3.9 volts each.

Would it be possible to test whether or not the I2C bus on the px4flow is broken, using QGroundControl or otherwise?

I greatly appreciate anyones help troubleshooting this.


Hey @Thomas_Kirven,

if you have an arduino, you could test your PX4Flow I2C connection using this library.

Cheers and good luck,


Thanks for the reply Nafnaf,

I tried the “basic.ino” script from this library using an arduino uno, and I get the error
“ERROR [PX4Flow] : Timeout reading PX4_Flow.”
followed by

It seems the problem might be the i2c bus itself. I was wondering if there is way to determine if there’s a problem (electrical short or something) with the i2c bus using other means, say testing the voltage of SCL or SDA against what they should be when not connected to another circuit.

It seems unlikely there is, but I am not an electrical engineer, so I’m not sure.