I'm configuring ADC0_3 and ADC0_12 for LPC55S28. ADC0_3 can get different values for different input voltages, but ADC0_12 always gets 4092~4095 for any input voltages. Please help to check what is the possible cause of this issue. Attached my current changes for ADC
Please check your hardware to verify whether ADC0_12 is connected to a high voltage on the board. Also, please confirm that you are connected to the correct pin.
Hi Alice, I've tested the input voltage of ADC0_12 pin on the MCU is 1.9V, so the hardware should be ok. but the adc value is still in range of 4091 and 4095
I connected to ground and the adc value is still not right. I have trouble using config tool to setup adc. So I used the sample code lpadc_polling from the SDK. I only change the ADC channel to ADC0_12 and it still doesn't work. The ADC0_3 is ok. Could you please help to check based on the sample code and my configuration?
I tested on the evk, and tried removing the R75 and press the USER button(SW3), adc value is still the same, around 4094~4095. Please help to check again.
