I have an xbee set up to remotely control an object outdoors. I have it connected to a battery and a solar panel. I want to monitor the charge of the battery and the simplest way I have come up with is to read the voltage of the battery.
I am using a voltage divider to reduce the voltage down to 0v - 3.3v from 0v to 20v. I plan on sending a command to turn pin 1 on to switch on a transistor which in turn will allow power to flow through the divider. I would then like to send a command to read the value of pin 3 which is hooked up to the divider. I will then turn pin 1 off.
I am doing this to save as much power as I can. I figure this is better then having the remote xbee use power to send multiple sensor packets when all I need is one at most in a day.
I cannot find a command to request single piece of sensor data.
Any ideas?
Thanks!