Boe Bot Battery Charge Level

Ket Halpak

Hi Everyone

Is there a way to determine the charge level of the batteries of my boe bot? Im using the Li-ion battery pack and what I want to be able to do is check the charge level of the batteries and if they are at a pre-determined level I can have it move to a certain position.


Cheers,

Martin_H

The book "Robot Builder's Bonanza" by Gordon McComb on page 207 and 208 describes how to monitor battery voltage using a zener diode and a comparator IC. Essentially you use the zener diode and a resistor to create a reference voltage and the comparator measures the batteries against this reference. As long as the battery outputs more than the trigger voltage the comparator outputs logical 1 which the BS2 can detect. If the voltage sags it outputs zero which tells the robot it is time to react.

I looked for an online version of the schematic but couldn't find one. But with some digging you might be able to. As an aside Gordon's book is often the first place I go with questions like this because it usually has the answer.

Ket Halpak

Thanks Martin, I shall purchase a copy of this book as it sounds rather usefull

Matt Gilliland

Hi Ket - Welcome to the Forums!

Martin's suggestion is good - Gordon's book is a "must have" IMHO...here's another tactic:

You could put a simple a/d converter on the BoeBot (like and ADC0831) - the code's readily available, and then you could monitor the level as it's dropping during use. In my tests here, (if I remember correctly), I think the BoeBot will run for 6 hours? on a fully charged Lion pack.

-MattG