I have a 25K OHM potentiometer wired to (3x) 1.05a drivers.
I’d like to display the amount these drivers are dimmed on an LCD display.
From what I’ve read, it may not be possible to achieve my goals with Arduino.
The datasheet suggests that you can connect the DIM pins (DIM+ and DIM-) in parallel, and control several drivers with one pot.
Pot value must be >= 100k/N drivers to get full brightness.
A 25k pot would be ok for four drivers, but not for three.
Three drivers and a 25k pot would be ~75% max LED
If… you can do this, then there will be a voltage (0-10volt) across the DIM pins, that could be measured with a DMM.
It seems this is all secondary (low voltage side), so an Arduino should also be able to measure that voltage.
Because the 1:1 voltage divider to bring that 10volt down to 5volt is connected in parallel with the pot, resistor values have to be high. e.g. 47k:47k is essentially the impedance of another LED driver.
Not sure what current limitation has to do with it (the quote).
You can also turn things around, and let the Arduino be the ‘pot’ that controls the drivers.
All you need is four PWM pins, four opto couplers and four resistors.
That will PWM the LED drivers with a value generated by the Arduino.
The Arduino will know that value, so can also display it on an LCD.