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Reply To: I2C and power management

Home › Forums › Mayfly Data Logger › I2C and power management › Reply To: I2C and power management

2021-02-18 at 5:56 PM #15155
neilh20
Participant

    Hi @mbarney  I have come across the I2C issue, and trying to remember what I did, or solution. There was an update that  could fix it, but of course that is a fork.

    It might have been that a wrongly soldered I2C for a humidity device caused the problem for me. Arduino paradigm is typically normal use cases.

    The Mayfly 0.5b has pullups R8 & 10 of 2K.  The ADS1115 board has its own pulls up of 10K.

    https://learn.adafruit.com/assets/36145

    The ADS1115 digital inputs are specified for 0-5.5V, which I think means they won’t take any current when turned off V=0. However the  boards pull down Rs would likely interfere with the operation of the pull ups R8&10

    So I wonder if desoldering the  ADS115 boards I2C pull-ups would make a difference. Just a thought.

    I recently used an LTC2942 directly connected on  the Mayfly I2C no pullups, it is similarly specified on inputs 0-6V.  I had no problem communicating on the I2C.