Analog value not changing on local device

Hi,

We are reading AD1 off local xbee (S2C - through hole) setup as coordinator using API
AP =1 AO = 0 AD1 = 2 PR = 80 PD = 0 IR = 1770 (set to send samples). We get constant values from AD1 range of 518-520. Even when the voltage on pin 19 is 0. Pin 14 (VREF) is connected to 1.2v.

We expect values as follows
Pin 19 0.812 v - expect AD1 = 692
Pin 19 0.734 v - expect AD1 = 630
Pin 19 0.677 v - expect AD1 = 577

Using (Pin19Volts/1.2) * 1023 = AD1Value

Any ideas why AD1 is only changing in the range of (518-520 - mostly stays at 520 even when voltage on pin 19 = 0)
Thank you

Are you sure you have both the internal pull up disabled and that you enabled the proper ADC line?

Thank you… Yes the settings are in the post. I found the issue pin 19 on the xBee is dead. Changed xBee all is working. Thanks again for your response.

Sounds like that pin got over voltage at some point.