BatteryVoltageTesterRev0

//This program goes hand in hand with ESP32RCVehiclePowerCircuitSchematicRev0.  This is designed to test the battery voltage for two 4.2 V LiIon batteries which have been placed in series
#define R1 100 //Resistor 1 value in kΩ - Used to Measure Combined Battery 1 & Battery 2 Voltage
#define R2 10 //Resistor 2 value in kΩ - Used to Measure Combined Battery 1 & Battery 2 Voltage
#define R3 100 //Resistor 3 value in kΩ - Used to Measure Battery 2 Voltage
#define R4 10 //Resistor 4 value in kΩ - Used to Measure Battery 2 Voltage
#define ADC_REFERENCE 1100
#define volt1P 32
#define volt2P 33

float volt1, volt2; //Battery 1 & 2 Combined Voltage = volt1. Battery 2 Voltage = volt2
float volt1S, volt2S; //Voltage 1 and 2 Scaled to Account for Voltage Dividers
float batt1V; //Battery 1 Voltage after Battery 2 Voltage has been subtracted out using KVL

void setup() {
  Serial.begin(115200);
  pinMode(volt1P, INPUT);
  pinMode(volt2P, INPUT);
}

void loop() {
  volt1 = analogRead(volt1p)*(ADC_REFERENCE/4096);
  volt2 = analogRead(volt2p)*(ADC_REFERENCE/4096);
  volt1S = (volt1*(R1+R2))/R2; //Volt 1 Scaled to the Appropriate Value using the VDR
  volt2S = (volt2*(R3+R4))/R4; //Volt 2 Scaled to the Appropriate Value using the VDR
  batt1V = volt1S - volt2S; //Battery 1 Voltage
  Serial.println("Battery 1 Voltage: ");
  Serial.print(batt1V);
  Serial.println("Battery 2 Voltage: ";
  Serial.print(volt2S);
}
//References
//Reference 1 https://en.ovcharov.me/2020/02/29/how-to-measure-battery-level-with-esp32-microcontroller/
//Reference 2 https://docs.espressif.com/projects/esp-idf/en/v4.4/esp32/api-reference/peripherals/adc.html