@Paul_M,
I use Mode 8 [Edit: Mode 7] and connect the Boron to the Normally Closed (NC) pin on the Relay.
The Timer Relay Board uses 580 mW when the relay is energized and 150 mW when it’s not.
By using Mode 8 [Edit: Mode 7] and the NC output, the Timer Relay spends most of the time in the “lower” power state.
The only time the Relay is energized is when the Webhook response hasn’t made it back to the Boron, so the Relay is energized (580 mW) to completely Power Down the Boron for the selected amount of time.
The Relay Timer Board is obviously NOT a low powered device, but Mode 8 helps.
For anyone that’s interested, as Paul mentioned the Relay Timer requires a 12V power source.
You will need to add 150 mW (~12mA @ 12V) to your power budget.
But this usually isn’t a problem for Remote Installs since you will be moving up to a 12V SLA battery and 12V Solar Panel anyway. I normally don’t even bother with Sleep at that point.
It works fine for “mains” powered units using a 12V DC power supply.
Remember, you can’t also use the Boron’s Li-Po with this setup.
That would prevent the Boron from shutting down and rebooting during a cloud failure event as the Relay Cycles.
In my experience, I’ve never had a $5 Timer Relay board fail on the test bench or in the field.
I’ve purchased them in large lots for $2 each in the past.