I don't know of any software fix for a signal that is out of the range of the ADC input.
MS Naila Munaf wrote: > You mean i should use a DC level shifter in hardware so that signal will > be positive all the time,But im preferring not to use it,instead i want > to make some changings in software so that it can read negative values too. > > > Date: Fri, 13 Aug 2010 13:38:07 -0600 > > From: sc...@santafe.edu > > To: hmitvoms...@hotmail.com > > CC: tinyos-help@millennium.berkeley.edu > > Subject: Re: [Tinyos-help] (no subject) > > > > If it's bipolar maybe it needs a shrink? > > sorry....couldn't resist. > > > > You'll need to bias the signal up such that it never > > goes below 0v or above the nominal 3.3v supply voltage. > > It might be as easy as using a couple of resistors, one > > to the signal and one to the supply. I'd start with > > around 10Kohms and see what ratio was needed to mix > > the signals together correctly. I think, but will not > > guarantee, that most micro-controller's can take > > very low current input that is out of their supply > > voltage range without damage while you are experimenting. > > > > MS > > > > > > Naila Munaf wrote: > > > Im using imote2.And I want to read a bipolar signal from ADC > > > Generically, tinyos-2.x/tos/sensorboards/im2sb/examples/TestMax136 can > > > read only unipolar value of a battery voltage.How should i edit it to > > > read bipolar signal using ADC. > > > > > > > > > > ------------------------------------------------------------------------ > > > > > > _______________________________________________ > > > Tinyos-help mailing list > > > Tinyos-help@millennium.berkeley.edu > > > > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help _______________________________________________ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
