From: Demetris Z. <fgc...@cy...> - 2007-02-19 20:23:39
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You don't actually need the whole Governor set , just the sensors. They are 2 magnetic sensors placed on each side of anything that is rotating(in the case of a heli you use it on the Main Gear) When it rotates you can calculate the speed from the Pulse Width Modulation. (PWM) Demetris Z. ----- Original Message ----- From: "Demetris Zavorotnichenko" <fgc...@cy...> To: "General mailing list for gumstix users." <gum...@li...> Sent: Monday, February 19, 2007 10:17 PM Subject: Re: [Gumstix-users] Simple feedback by brushed motor > It's called a Governor. > > You can find it at any hely hobby store > > > > Demetris Z. > > > ----- Original Message ----- > From: "J.p.Lien" <jl...@ne...> > To: <gum...@li...> > Sent: Monday, February 19, 2007 10:08 PM > Subject: Re: [Gumstix-users] Simple feedback by brushed motor > > >> <wbig <at> fastwebnet.it> writes: >> >>> >>> Hi all, >>> I'm working to a quadrotor (draganflyer V) project, using a gumstix with >>> a >>> robostix. I'd like to estimate rotors speed avoiding quite expensive and >>> hard >>> to install optical encoder or similar. >>> Connecting an oscilloscope, I noted that my brushed motors generate >>> little >>> picks every rounds, and I thought that maybe I can read this signal >>> using >>> a2d >>> pins on robostix, but the signal is really noisy... >>> Someone already tried to do something like this? Or do you have other >>> ideas? >>> >>> Thanks >>> Claudio >> >> Claudio, >> >> I don't know if this will help you, but I have done something similar >> with >> a >> brushless motor on a recent project. I used the input capture (ICP) unit >> on the >> Robostix to measure the width of the drive pulses. I think the a2d is >> probably >> too slow to catch a dynamic signal like that (although perhaps the analog >> compare unit would work for you). >> >> The noise you are seeing is probably the PWM that's applied by the speed >> controller to throttle the motor. If the PWM frequency is higher (or >> lower) >> than the pick you're looking for, you could maybe get rid of it with an >> RC >> filter. I haven't done much with brushed motors, so I don't know if this >> will >> be the case. If not, the idea of using a hall effect sensor is probably >> the way >> to go. >> >> Hope this helps, >> J.p. Lien >> >> >> ------------------------------------------------------------------------- >> Take Surveys. Earn Cash. Influence the Future of IT >> Join SourceForge.net's Techsay panel and you'll get the chance to share >> your >> opinions on IT & business topics through brief surveys-and earn cash >> http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV >> _______________________________________________ >> gumstix-users mailing list >> gum...@li... >> https://lists.sourceforge.net/lists/listinfo/gumstix-users > > > ------------------------------------------------------------------------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get the chance to share > your > opinions on IT & business topics through brief surveys-and earn cash > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users |