The STM32F303RBT6 ADC2_IN3 data is abnormal when the pin PC4 set high.

[lYong.1]

The STM32F303RBT6 ADC2_IN3(PIN PA6) is connect to GND .When the pin PC4 set high,the ADC_IN3 read a abnormal data 0x70. When the pin PC4 set low,the ADC_IN3 read a normal data 0x00.

Which the PC4 set high,is affect theADC2_IN3 sample .

[waclawek.jan]

How exactly is PC4 set in GPIO?

> When the pin PC4 set high

Internally, i.e. setting PC4 to GPIO Out; or externally?

Doesn't the voltage on PC4 exceed VDDA?

JW