hi,
Set VR1 for 0.5V and adjust VR2 to give 1.5V out [Y]
That CA3140 seems to be limiting at a lower voltage than I would expect, I'll check it out.
Once you have set the VR1 pot to 0.5V and VR2 to give 1.5V out you can connect this to your PIC adc input and try your PIC program.
Adjust VR1 as you test with different voltages, but leave VR2 unchanged..OK
When you are happy with that test, connect the AD736 to the CA3140 as shown in the dwg,,, remove the test pot input first.
Set VR1 for 0.5V and adjust VR2 to give 1.5V out [Y]
That CA3140 seems to be limiting at a lower voltage than I would expect, I'll check it out.
Once you have set the VR1 pot to 0.5V and VR2 to give 1.5V out you can connect this to your PIC adc input and try your PIC program.
Adjust VR1 as you test with different voltages, but leave VR2 unchanged..OK
When you are happy with that test, connect the AD736 to the CA3140 as shown in the dwg,,, remove the test pot input first.