我的项目使用到 W806 的两路 ADC 通道: ADC3, ADC4. 原理图如下
ADC 输入引脚 ADC_3 的电压波形不稳定, 如下图所示
这种现象是什么原因引起的?
ADC 相关代码如下:
Very strange and incomprehensible circuitry.
Okay, at the ADC3 input you want to monitor the battery voltage. Maybe Li-Ion 3. 7 (4. 2 max) volts. Then the maximum battery voltage needs to be scaled to 2. 4 volts. Then the lower arm (R17) of the divider is about 270 kOhm.
What is VCC voltage? If 3. 3 volts, then the ADC4 input will have a voltage of about 2 volts if the sensor is not connected. The common connection point R18/C12/R14 is the summing point
Disconnect ADC3/ADC4 from your circuit and look at the ripple separately from the MCU inputs. There may be a problem with the controlled voltages. What is the frequency and amplitude of the pulsations?
I don't speak Chinese and may have misunderstood your question.