@shicks Thanks for those details. I wonder whether it could be the turbidity sensor, rather than the Mayfly, that’s actually drawing power, but I wouldn’t have thought it could do that while (or if) the Mayfly is sleeping. A bit more about my circuit:
I’m powering the Turner from Mayfly’s switched 3V3. The Turner’s analog output is 0-5V, which I’ve connected to an external ADS1115 ADC. The Mayfly’s communicates to the ADC over I2C via a logic level shifter. The Turner also has a digital input to trigger its wiper, and a digital output that signals when the wiper is in its home position.
I’ve attached a wiring schematic. Does anything jump out that could be leaking current during sleep?
@neilh20 Thanks for the feedback, and I’ve got a very similar spreadsheet! I’ve also just received the parts for a FTDI cable to get serial output without supplying power – thanks for your work with this!