SparkFun MS5803 I2C issue

[trjw]

Hi,

So I found this old post:

I2C issues with MS5803-14BA Breakout [SOLVED]

This is probably something really silly, but… I’ve been playing with a new pressure sensor from SparkFun the MS5803 ( https://www.sparkfun.com/products/12909 ) breakout. I have this working on an Arduino Uno using this library ( https://github.com/millerlp/MS5803_14 ) and have tried to use it on the Spark (with a couple of modifications, namely change D1 and D2 references to Z1 and Z2 to get around naming conflicts) but I just can’t get the Spark to talk to the sensor. The sparkfun board has …

and I am seeing a pretty similar issue. I can talk to the MS5803 over I2C just fine from a regular arduino (ATMEGA 2560 3.3V), and porting the Sparkfun_MS5803_I2C library to particle was trivial.

I can talk to another of the project's I2C sensors from my photon just fine, but cannot for the life of me get anything out of the MS5803.

I put a digital scope on the I2C bus and can see the photon trying to write to the I2C bus, but there is never any ACK. Again, if I connect a different sensor (a simple Baro sensor) I can see the whole conversation just fine.

I've tried the clock stretching hack from the thread I linked above, but saw no change.

Would love to hear from anybody with either I2C debugging/troubleshooting advice or if they've managed to get this working.

Thanks,

John