Heres a schematic of the power selector for the transmitter power
There are transistors which are all connected to pins on the microcontroller. The microcontroller can control each switch individually .
There are diodes on top with a voltage drop of 2V. Therefore after each diode the voltage is lowered by 2V. Microcontroller switches the transistors to select voltage at transmitter.
Using this pseudo code on the transmitter :
Set to 12V
Send Byte (12)
Set to 10V
Send Byte (10)
and on and on until 2V
Then the receiver just checks to see which bytes it gets and can therefore determine range.
Any feedback or comments?