I test the ADC by measure the voltage in Linux:
and get the adc voltage by:
adc_voltage= in_voltage0_raw* (1800 / 4095)
When I connect the ADC0(X14 pin1) to the GND of the Apalis evaluation board, the adc_voltage stabilize on 2.20mv instead of 0.0v.
And the value does not correspond to the external source voltage connected to ADC0 input at all.
external source voltage 0.8v → read adc_voltage 0.67v
external source voltage 1.5v → read adc_voltage1.27v
Is any problem with adc on the Apalis evaluation board v1.1c?
Any idea please tell me.