I would like to make a circuit board that turns on 3pcs RGB LEDs (not strip) on certain days and turns it off on other days. The LEDs turned on about 5 days in a month (10-12 hours a day); the other days they are turned off.
The hardest part is to make it portable, so the best would be if this whole thing is operated on cell battery included the LEDs at least 3 months (e.g. AA batteries, in the worst case with a 18650 battery).
What would be the best component to this project?
Arduino Nano/Micro with RTC (DS3231 or PCF8563?), ESP32, or Pi Pico?
RGB LED ws2811, ws2812/b/d?
I don't want wifi or any wireless connection, only the simplest solution.
The uC in this case will not make much of a difference. Even an Attiny85 can handle this task. So I would choose one that spends less energy while sleeping.
If the place has wi-fi, the ESP32 can get the time from the internet with no need for the RTC. In the other hand, the RTC can be used to wake the uC when it's time to turn the LEDs on.
I agree, because you'll need a good amount of energy to power the project for a year. Only the 3 RGB LEDs (WS2812) will require 180mA at full strenght. A single 18650 battery would give you just a few hours and doesn' have enough voltage for the LEDs.
For how long time and at what intencity? Measure the current used and calculate the number of mAh used. How many such cycles do You want the build to run before charging/changing the batteries?
About 10-12 hour a day. I don't know how bright these LEDs, so lets say 50% intencity.
It would be great if it can run min. 3 months before change/charge battery.
Maybe other type of LED has minimal energy consumption?
That's was my thought too. The RTC wake the the uC when needed the LEDs then send to sleep.
You need to measure that in order to know. Transfer 50% intencity into mA etc etc.
3 cycles means 3 years.... Investigate the self discharge of the battory during such a rather long time.
My conclusion is that You would need a lot bigger battery than You dream about.
No guy in forum can give a clear answer. You need to start from the very bottom measuring all the small parameters and sum them up.
Speculations will only waste Your time and money, and helper's time.
I understand that, but I don't want to buy anything for this project without planning.
For example I don't want to buy all of the mC I meantioned, just to try which one consumes the least energy. That's why I asked (you) more experienced users.
Compare the current drawn in sleep mode for those controllers reading their specifications.
Set up the LED and test what intencity is satisfying. Only You can tell, and measure the current.
No helper can tell that. From there the need for the battory capacity, mAh, can be calculated.