I’m building some low power RF sensor nodes and putting the ATmega328P in sleep (actually power down) mode between transmissions.
An issue that I’ve encountered is that whilst the ATmega is sleeping the millis timer stops causing the DHT library to return the same temperature until the ATmega has been awake for over 2 seconds.
In order to get around this I’ve been incrementing the millis timer manually with the duration of the sleep which initially seemed fine.
Having used this setup for a while I’ve noticed that the sensor reading is slow to adjust to big changes in temperature (e.g. blowing/breathing hot air just before the reading is taken) compared to taking readings with a delay of the same duration.
Has anyone been in this situation before or have any alternative solutions which still keep the low power requirement (looking at <1mA draw in sleep mode)?