I need to make an update. My pro micro is still working awter 2 weeks. I had no problem to charge rechargeable battery 1.2V.
I check how much amperes is drawing from power source, and was about maximal 70mA. Average is something about 40 - 50 mA.
I think is because that batery have internal resistance very high, and charging from pro micro is safe.
Now I am playing with different ways of coding to do this same thing.
And still I dont understand why PULLUP is affecting measurements if even voltage on battery is not affected at all.
Difference with PULLUP and normal INPUT measurements from pro micro show 100 steps higher.
I think some internal resistance in chip of pro micro somehow is affecting that.
Anyway, If I will use PULLUP, and I will adjust voltage per step for calculations. everything works great.
Paul__B:
I do hope that you do not mean to say that you have an output pin actually supplying 70 mA to a battery.
Yes, that's I mean. I tested on about 10 batteries.
But to charge battery I use only one at the time. I can imagine what can happened if I will use more pins with more batteries.
For now, I can confirm that charging 1 battery on pro micro is safe.
When I will have more time, I will try make picture and short video to show it.
Program is cutting of charging when battery will reach 1.35V This is nominal properly charged battery. Maximum could be 1.40V but when I try that, I never reach this voltage. Minimum voltage on battery was 0.8V.
And even now, writing that post, my pro micro is still charging next battery.
You should try it. And measure amperage for whole circuit.
