Hi folk,
I'm designing an intervolameter with ATMega328 and DS3231 RTC IC. I want to make my own circuit board for sake of simplicity. For prototyping i am using Arduino Pro Mini. I build RTC module based on this document provided by Adafruit. Only differance is i use CR2032 battery.
To build up the circuit first i solder RTC on SMD to DIP converter board. I check all pins to against short-cuts. Then connect to Arduino and battery. Load example sketch provided by Adafruit's RTClib. Works fine. Then disconnecting Arduino from power. Leting it work for couple hours. Then things gets interesting. RTC either not responding, or responds but starts from 0 each time i power off arduino despite of its connected to battery. Also battery voltage is downs to 2V.
After some trials with multimeter, i find out that when i try to test shout cut with multimeter Vin-GND gives 1 but Vbat-GND gives 300 to 500 but buzzer not activates. For fresh RTC, both results are 1.
For now i tried 4 RTC and 6 battery from different sources. Results are same. What might be cousing this problem?