Hi, I updated the schematic . I removed the integrator, as it's functionality depended on expensive auto-zeroing opamps and unreasonable capacitance values. I have a 4 hZ single pole filter here now, but I believe I'll replace it with a 2 pole filter. Otherwise, are there any thoughts on the updated schematic? Oh, also, i replaced the LED display with an LCD display for power saving purposes Ben On Tue, Feb 17, 2009 at 6:10 PM, Forrest W. Christian wrote: > Benjamin Grant wrote: > > that would be great to do it that way. I mean the OP950 just outputs a > > current signal, so are you suggesting to use 1 single opamp to be a > > transimpedance amplifier that outputs the voltage in a reasonable range > and > > then process it digitally? > > > That is roughly correct. Although I would probably bias the OP950 so > it effectively was a voltage source, not a current source, then amp it > up with an opamp. > > The question will be whether you have enough bits on the pic's ADC > (which is why I suggested a part with a 12 bit adc) to be able to handle > the dynamic range which is needed. > > -forrest > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist