Chain DualKey Power

#define PIN_ADC_CHRG 9
#define PIN_ADC_BATT 10
#define PIN_ADC_VBUS 2

float chgVoltage;
float batVoltage;
float usbVoltage;

void setup() {
  pinMode(PIN_ADC_CHRG, INPUT);
  pinMode(PIN_ADC_BATT, INPUT);
  pinMode(PIN_ADC_VBUS, INPUT);

  Serial.begin(115200);
}

void loop() {
  chgVoltage = analogRead(PIN_ADC_CHRG) / 4095.0 * 3.3;
  batVoltage = analogRead(PIN_ADC_BATT) / 4095.0 * 3.3 * 1.51;
  usbVoltage = analogRead(PIN_ADC_VBUS) / 4095.0 * 3.3 * 1.51;

  if (chgVoltage >= 1.4 && chgVoltage <= 1.8) {
    Serial.println("Battery is charging");
  } else if (chgVoltage > 1.8 && chgVoltage <= 2.4) {
    Serial.println("Battery is full");
  } else if (chgVoltage > 3.0) {
    Serial.println("Battery is not charging");
  } else {
    Serial.println("Battery charging status is unknown");
  }

  Serial.printf("Battery voltage: %.4f V\n", batVoltage);  // Unit: V
  Serial.printf("    USB voltage: %.4f V\n", usbVoltage);  // Unit: V

  Serial.println();
  delay(1000);
}