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View Full Version : PIC12F675 AD Reference problem



Andre_Pretorius
- 6th October 2011, 20:19
Hallo
I am trying to measure a output from a LM3914 bar display driver with a pic12 the problem is that if you measure from 0V nothing happens, if you measure from 5V you get a variance running up to 1.2V.
The probllem is that the pic analog input measures from 0V and not vdd and does not detect the change.
The question: can you configure the pic to use vdd as the refferance or is there maybe a other sollution someone can sugjest

Thank you

Dave
- 6th October 2011, 22:21
Andre, The normal reference voltage for the A/D of an 12F675 is the 5 volt source. However you can route the A/D reference to the GP1 pin and place an external reference voltage of your choice. As long as it is below or equal to the VDD of the PIC. Look in the data sheet for the device.....