You'll need a current shunt or similar, and I was going to suggest a=20 part I used on an eBike, but I forgot it was high-side, the INA169. I'm=20 sure there's a compliment for low-side, and using "low-side current=20 sense" as a search term on TI's web site turns up many results. "Half a=20 volt" and "small DC motor" don't quite narrow down the selection parameters= .. As for the software, sample the sense amp with ADC (maybe it's set up=20 as a peak detector) and do sumfin. Joe W On 6/22/2015 9:19 AM, David C Brown wrote: > I need an overcurrent detector for a small DC motor. I thought of using > low side sensing with the ADC of a PIC measuring the voltage across the > sense resistor and then doing the integration and peak suppression in > software. I can tolerate half a volt or more voltage drop in normal > operation. > > This seems to such an obvious idea that I am surprised that I can't find > any reference to it in a search for "overcurrent detection using PIC". = So > is there some gotcha that I am too stupid to see? > --=20 Joe Wronski jwronski@stillwatereng.net www.stillwatereng.net --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .