Post by thread:powering 12c509 at small scale

Hello, I am using the 12c509 on a really tiny robot. And I would like to power the PIC up with the smallest battery out there for about an hour. Anybody have ideas from experiences on what battery to use to last that long. Also, ideas/routines on the usage of the PIC to allow it to be as efficient as possible (I think using sleep command???) I am a little unclear in these places!! Could someone give me some advice and help, on what battery to use and how to make the PIC be as efficient as possible while still allowing to change outputs on change of inputs. Thank You Again to all! +--------------------------+ | Sep Seyedi | | -> spam_OUTmeTakeThisOuTsep.2y.net | | -> http://sep.2y.net | +--------------------------+

Sep Seyedi wrote: >I am using the 12c509 on a really tiny robot. And I would like to power the >PIC up with the smallest battery out there for about an hour. > ... >Also, ideas/routines on the usage of the PIC to allow it to be as efficient >as possible (I think using sleep command???) > Sep: I've played with the '508s quite a bit, and typically measure about 0.6mA total to the chip when on it's internal RC. Pretty well any battery ever made will last an hour at this rate. If you use the sleep mode, current will drop to almost immeasureable levels. What you really have to look out for is the current drawn by the pullups and your external circuitry. These can really add up in a hurry (have you looked into interfacing to VMOS power transistors rather than bipolars?). Jim Nagy Elm Electronics ICs for Experimenters http://www.elmelectronics.com/

related question. how long will 4 C batterieslast at 3mA? I am shooting for 1mA but I cant seem to get it that low. its a PIC16C65A, 24C65, DS1307, and a PIR motion sensor. should I keep trying(i.e. modify the PIR) or does 3mA sound like it is pretty low for all those things... >Pretty well any battery > ever made will last an hour at this rate. If you use the sleep mode, > current will drop to almost immeasureable levels