Sleep not shutting down fully

[JulesGren]

With the attiny412, I am using set_sleep_mode(SLEEP_MODE_PWR_DOWN); to shut down.

This should reduce the consumption from ~10mA to <1mA (should be in the order of 200uA)

However when doing so it actually reduces from ~10mA to 3.5mA the circuit comprises one attiny 412, with a 20k pull down resistor (on pa_2) with an open switch, supply is 5V and I have tried it with and without the 100nf cap across vcc & vdd - the cap makes no difference. (As does removing the pull down resistor - although a finger touch is sufficient to trigger the operation)

I have tried SLEEP_MODE_STANDBY and this also gives ~3.5mA.

So it looks like SLEEP_MODE_STANDBY and SLEEP_MODE_PWR_DOWN are identical.

Example code attached - i have tried a number of options to achieve this, but whichever method it gives the same current.

main1.cpp

[JulesGren]

Bit of an update, when the attiny412 is programmed the 10mA drops to circ 3.5mA upon sleep.

However if I program it and then remove-replace power the normal current is ~9mA (slightly lower) and drops to 200uA upon sleep (still higher than spec - but actually suitable for my application)

[felias-fogg]

The ATtiny412 is one of the 'modern' ATtinys. The right core for this one is the megaTinyCore, not ATTinyCore.

Apart from that, you figured out one important thing: Remove everything from the board, in particular the programmer, before measuring the sleep current.

200 µA is still too high, though. With the classic ATtinys, you had to disable the ADC before going to sleep. Otherwise, you got a sleep current around 200 µA. Perhaps it is the same thing here as well.