I2C Failure Requires Full Power Down To Recover

Troubleshooting
1

Hi, I’m having some odd problems with I2C sensors that I’m trying to get to the bottom of. Generally communication with the HTS221 on our board works fine, but in a small number of locations, we see the readings go haywire (over 100 percent humidity, over 100 degrees C). The sensor is still responding correctly with WHO_AM_I and calibraiton information requests, but the actual readings are a mess. Rebooting the sensor and/or the electron does not resolve the problem. Only a full power down (battery unplugged as well) will restore the system to valid temperatures and humidities.

I had been assuming that the problem is with the board or the HTS221, but I recently saw a different I2C device fail similarly.

Obviously, it could still be the board, but I’m wondering if it’s possible that something on the Electron is getting scrambled to the point where a full power down is required to restore it. Is that even a possibility I should be investigating?

Thanks

2

Looks like it was a failure of the I2C stack on the Electron. The devices were all remote, so I was getting limited information and it seemed to me like it wasn’t the entire I2C bus. Went to retrieve one and took a closer look. A call to Wire.reset() did the trick in the end.

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