I2c troubleshooting

Yes, each sensor have their own pullups.

@highbyte error code documentation is coming - we’re just rationalising the values before publishing. A value of -1 means we sent a start but timed out waiting for the bus to be released.

Thank you for the info. If I find what is wrong I’ll post it here for future reference.

You may have too strong a pull-up on the bus, in that case. There should only be one set of pull-ups on an I2C bus. This may not be the issue here, as only 2 sets are probably manageable.

However, you say you have two sensors. Are they the same? Every i2c device needs to have a different address - two identical devices will not work, you’d need to change the address of one of them (most I2C devices have a couple of strapping options for addresses).

I have setup the other one to have different address so that is not a problem. The pullups, as you mentioned, might be the problem. Each sensor has 3.2k pullup.

There might be a problem with the sensor batch I got. One of them is short circuited out of the box. So I ordered couple of more and test with them as soon as they arrive.