From: /<evin <kev...@ya...> - 2008-08-11 00:45:16
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Hi Dave, I have used the wallwart and I have tried exactly 5v from a 7.2v battery regulated down. I have unplugged everything (except my quad encoders and serout) and I have only my maxbotix left plugged in. The AVCC pins all tell me 4.92v. With my maxbotix sensor disconnected from robostix and powered up seperately it provides a consistent voltage reading on the analog pin when ranging an object. When I connect it to my robostix and measure at the sensor analog pin the voltages drifts considerably. Kevin Dave Hylands wrote: > > Hi Kevin, > >> I have a robostix and a Maxbotix EZ3. >> My issue is that when I connect my sonar directly to clean 5v power a get >> a >> steady analog output on my DMM but when I use the robostix 5v and gnd my >> readings swing wildly (both on DMM and on serial output from robostix). >> >> I had 3 ir sensors all connected which exhibited similar behavior but >> which >> seemed to be a little more tolerant. >> >> My DMM tells me the AD voltage is 4.92v. > > What voltage are you feeding into the robostix? > > It really wants about 5.4v to get a nice 5v output. Also be aware that > the voltage regulator on the robostix is limited to 500 mA. Some IR > sensors (like the GP2D12) draw instantaneous currents of 200 ma, so > hooking up alot of them may be overloading the voltage regulator. > > There's nothing wrong with using additioanl external voltage > regulators to provide the 5v for your sensors. > > -- > Dave Hylands > Vancouver, BC, Canada > http://www.DaveHylands.com/ > > ------------------------------------------------------------------------- > This SF.Net email is sponsored by the Moblin Your Move Developer's > challenge > Build the coolest Linux based applications with Moblin SDK & win great > prizes > Grand prize is a trip for two to an Open Source event anywhere in the > world > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > -- View this message in context: http://www.nabble.com/Robostix-ADC-flakey-power-tp18914867p18918635.html Sent from the Gumstix mailing list archive at Nabble.com. |