Hi, my Arduino is driving a GSM SIM800L module via 2 pins and SoftwareSerial.
For power saving, i’m switching the GSM module OFF. I’m hunting any power i can save and i noticed that the TX pin used on the Arduino is sucking about 0.5 mA when the SIM800 is OFF and the Arduino in power sleep.
I tried to switch this TX pin from OUTPUT to INPUT with the pinMode command in my powerdown() function. This effectively solves the current flow problem but when i drive the pin back to OUTPUT when the Arduino wakes up, the serial port doesn’t work anymore…
Any suggestion why, and how i can solve this ?