The fancy little set voltage and current (or more so limit for safety)
Guessing that the internal mechanics are doing some hardware check, or is it all software guesstimating?
If it’s a hardware check, can this be accessed in some way? It sounds like I can find out the current battery voltage somehow?
Hi Kelvin! There’s no way to read these values from an LED strip in hardware on a standard Arduino without additional hardware components. The FastLED code makes a calculated approximation of what the power draw WOULD be if left unchecked, and then automatically uses the (nondestructive) master brightness control to stay within the specified power envelope.
As is often the case, the code itself has some more comments:
https://github.com/FastLED/FastLED/blob/master/power_mgt.cpp
https://github.com/FastLED/FastLED/blob/master/power_mgt.h
As for finding out the current “battery voltage”, there’s no standard, but many AVR (regular Arduino) chips can tell you the current voltage on the power rails. See http://provideyourown.com/2012/secret-arduino-voltmeter-measure-battery-voltage/ for one example how (and Google is your friend – other people have better code for this, I believe).
Also, a note on “reading the battery state-of-charge”:
If you read the battery level while it’s driving 100 LEDs to full white, you’ll get a lower voltage reading than if you read the battery level while it’s not lighting any LEDs at all.
Determining state-of-charge of a battery is actually a pretty hard problem – but if you can control the power load during the moments before when you take the reading (remember: chemistry takes time to happen), you can let this settle down and then get a stable and useful reading.
heh, i thought as much… i am going to implement a kind of current battery % remaining, but was half hoping that the super fastled was going to skip a massive chunk out for me!
time to investigate!
@Mark_Kriegsman Thanks for the links! I have been using a voltage divider to measure my LiPo’s, I am excited to try out a new technique (possibly).