Arduino - SoftwareSerial library and interrupts

January 21, 2015 Oliv'

I wanted to use sleep functions of the Atmega328 (in power-down mode), in conjunction with Arduino’s software serial library: it turns out that all interrupt vectors are enabled in sleep mode.

So the workaround is to start the serial communication when needed with softSerial.begin( BAUD_RATE)), then stop it with softSerial.end(). Also, the .end() can be just before going to sleep, and the .begin() just after.