February 2023

STEVE   Ultra low power IOT device - operates  for a year between charges! 

ESP module plugs onto a custom PCB base board which has a MOSFET high side switch that controls power to itself.

TPL5010  is a nano-power timer IC, generates a pulse every 2 hours.

The timer pulse fires the mosfet, the ESP boots up and immediately drives a digital output line HIGH to hold the mosfet on, before the timer pulse disappears.

The ESP then reads the sensor(s) and uploads the data to google sheets (via If This Then That).

The code then releases the mosfet, it turns off and this cuts power to the board including itself.  Lights out!!  Only the nano-power timer stays on.

2 hours later the cycle repeats.

A 2000mAHr LiPo can power this with 12 readings per day for 12 months.  There's a LiPo charger module on the custom PCB also.

Schematic below.