goal: robot leaves charging station when battery full, returns when battery falls below threshold. need: battery monitor

Naturally I want a battery-monitoring circuit/electronics that uses as little power as possible. I'd be surprised if such a circuit isn't available off-the-shelf, but I've never seen one advertised as a standalone component I could plug in to add it to my project. Speaking of "my project," it doesn't exist in physical form yet, only in my head, but I'm thinking of an R/C car body, big enough to carry a small video camera or 2; the charging station could be solar panels in a fixed sunny spot that it navigates to, or perhaps (a) panel(s) on board the car (so it could find a sunny spot anywhere during the day, e.g.).

What you are looking for is a trivially simple subsystem - monitor the battery volts with an A/D converter in your controller, trigger the find home function when it gets a low reading.
landru (author)  steveastrouk7 years ago
thanks for replying. So, just a wire from the battery's positive terminal to a microcontroller input pin -- with a resistor in between to limit current, perhaps?

would there be a minimum amount of current needed to get a reading?

obviously I'm no electronics engineer.
If its an input pin, and you have an analogue to digital converter inside the microcontroller, like an arduino does then yes.Otherwise you add an external ADC and read that with the micro.