I work on an Arduino based beehive scale project.
My circuit is wired and it works perfectly (measure temperature, humidity, weight every day at 6 AM, 2 PM and 10 PM and sends it to the server by GSM module) while powered by 5 V and 3 A.
My goal is to power everything with 12 V battery pack which will last for at least 1 year. The circuit consumes about 20-30 mA (it is because Arduino is turned on, sensors work all day long, GSM module is an active whole day, etc.) and about 150 mA while GSM is sending a message (few seconds).
I was looking for the best way to solve my problem and found this guy:
My questions are:
How can I program a DS3231 RTC module to power on Arduino at a specific time and wait for Arduino to tell him when to power off or be turned on for example 5 minutes until the server gets all the measurements? How long will the RTC module's battery (CR2302) last in my case? Is Arduino's watchdog timer in combination with Arduino's sleep mode a better and easier solution to fix that?
PS. Now Arduino works all day long and delay is specifying time when it will send measurements to server.