<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">The following from jcw is also of interest<div><br></div><div><a href="http://jeelabs.org/2013/05/17/zero-powe-battery-measurement/">http://jeelabs.org/2013/05/17/zero-powe-battery-measurement/</a></div><div><br><div><div>On 16 May 2013, at 22:30, Damon Hart-Davis wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>DHD20130516: Useful IRC session about H-bridge direct motor drive, including outline schematic from Mike (only needs two digital lines to drive it) and notes about current monitoring and supply management.<br><br><a href="http://www.earth.org.uk/OpenTRV/circuitFragments/MS20130516-hbridge-2wire.png">http://www.earth.org.uk/OpenTRV/circuitFragments/MS20130516-hbridge-2wire.png</a><br><br>http://www.earth.org.uk/OpenTRV/circuitFragments/MS20130516-hbridge-2wire.txt<br><br>The neato thing there may be that Schottky diode + small super cap may isolate the AVR from motor-induced voltage sags and with care may allow AVR to maintain software RTC running while main batteries are swapped out. (I can put TMP112 and RFM22 on other side of that diode if need be to get current draw down to 1.3uA.)<br><br>Plus Bo has made enough space to possibly squeeze the actual H-bridge components in! B^><br><br>Rgds<br><br>Damon<br>_______________________________________________<br>OpenTRV-dev mailing list<br>OpenTRV-dev@lists.opentrv.org.uk<br>http://lists.opentrv.org.uk/listinfo/opentrv-dev<br></div></blockquote></div><br></div></body></html>