For my first time trying to establish wireless communication, I thought about sending varying duty cycles of pwm, to the attiny 85.
One attiny85 would have buttons that would change the duty cycle of a pwm signal. This pwm signal is then inputted into the ADC of the attiny85 where is it then sampled and the voltage level is read.
Since different duty cycles of pwm, result in different voltage levels I thought the ADC wouldn't have a problem reading the voltage of the pwm.
However, this did not work not, instead the leds started blinking at certain rates depending of the duty cycle that was created (button pressed). It seemed that the ADC wasn't working with the pwm signal at all.
After some time, I found out that reducing the pwm frequency and getting the receiving attiny85 to measure the duty cycle of the pwm instead of treating it like a voltage value would be a better way of sending data.