I have a device with 3 states : offline, online and standby. The goal is to get a UNO control this device.
The 3 states are activated/controlled by a small amount of voltage: ≥3.5 V - 1.2 V to 2.9 V - ≤0.8 V.
I make some tests with a CR2032 lithium battery, connected to the device input-control pin, and it works fine for 2 states.
So far I could understand that I can generate theses values from any pwm arduino pin using a Low pass filter.
Question is: what are the corrects value for the resistor and the cap needed. Easy way to get/calculate the right values ?