Hello, i have an arduino project where i start my parking heater on my car via can-bus by sending an sms to a SIM800L module.
The SIM Rx and Tx pins is connected to arudinos i/o pins 7 & 8.
The current withdrawal right now for all devices is 35mA on 12v. My worries is that it will drain the battery if the car is unused for a long time.
I played around with different arduino deep sleep libraries and got the current down to around 20mA, but i could not wake it up. Can you guys guide me how it should be done?
I guess the first message from the SIM will be discarded while the arduino is waking up, but that is no problem, i can send 2 messages.