Circuit Documentation

Summary

This circuit is designed to measure voltage and current using a voltage sensor and a current sensor, interfaced with an ESP32 microcontroller. The circuit also includes a power supply system that converts AC to DC using a power transformer and a bridge rectifier. The measured values are processed and displayed by the ESP32.

Component List

1. Voltage Sensor DC 25V

   • Pins: +, -, output, gnd, vcc
   • Description: Measures DC voltage up to 25V.
   • Purpose: To measure the voltage in the circuit.

2. Current Sensor 5A

   • Pins: 1, 2, GND, OUT, VCC
   • Description: Measures current up to 5A.
   • Purpose: To measure the current in the circuit.

3. Bridge Rectifier

   • Pins: Source_in-, source_out-, source_out+, source_in+
   • Description: Converts AC to DC.
   • Purpose: To rectify the AC voltage from the transformer to DC.

4. Power Transformer (220V to 24V)

   • Pins: 2 - Primary, 1 - Primary, 3 - Secondary, 4 - Secondary
   • Description: Steps down 220V AC to 24V AC.
   • Purpose: To step down the high voltage AC to a lower voltage suitable for rectification.

5. ESP32

   • Pins: EN, VP, VN, D34, D35, D32, D33, D25, D26, D27, D14, D12, D13, GND, VIN, 3V3, D15, D2, D4, RX2, TX2, D5, D18, D19, D21, RX0, TX0, D22, D23, BOOT
   • Description: A microcontroller with Wi-Fi and Bluetooth capabilities.
   • Purpose: To process and display the voltage and current measurements.

6. Electrolytic Capacitor

   • Pins: -, +
   • Description: 0.00047 Farads
   • Purpose: To filter the rectified DC voltage.

7. AC Supply

   • Pins: +ve, -ve
   • Description: Provides AC voltage.
   • Purpose: To supply AC voltage to the transformer.

Wiring Details

Voltage Sensor DC 25V

• output connected to ESP32 D34
• + connected to Current Sensor 5A VCC and ESP32 3V3
• - connected to Voltage Sensor DC 25V gnd, Current Sensor 5A GND, and ESP32 GND
• vcc connected to Bridge Rectifier source_out+, Current Sensor 5A 1, and Electrolytic Capacitor +

Current Sensor 5A

• OUT connected to ESP32 D32
• GND connected to Voltage Sensor DC 25V -, Voltage Sensor DC 25V gnd, and ESP32 GND
• VCC connected to Voltage Sensor DC 25V + and ESP32 3V3
• 1 connected to Voltage Sensor DC 25V vcc, Bridge Rectifier source_out+, and Electrolytic Capacitor +
• 2 connected to Bridge Rectifier source_out- and Electrolytic Capacitor -

Bridge Rectifier

• source_out+ connected to Voltage Sensor DC 25V vcc, Current Sensor 5A 1, and Electrolytic Capacitor +
• source_out- connected to Current Sensor 5A 2 and Electrolytic Capacitor -
• Source_in- connected to Power Transformer (220V to 24V) 3 - Secondary
• source_in+ connected to Power Transformer (220V to 24V) 4 - Secondary

Power Transformer (220V to 24V)

• 2 - Primary connected to AC Supply -ve
• 1 - Primary connected to AC Supply +ve
• 3 - Secondary connected to Bridge Rectifier Source_in-
• 4 - Secondary connected to Bridge Rectifier source_in+

ESP32

• D34 connected to Voltage Sensor DC 25V output
• D32 connected to Current Sensor 5A OUT
• 3V3 connected to Voltage Sensor DC 25V + and Current Sensor 5A VCC
• GND connected to Voltage Sensor DC 25V -, Voltage Sensor DC 25V gnd, and Current Sensor 5A GND

Electrolytic Capacitor

• + connected to Voltage Sensor DC 25V vcc, Bridge Rectifier source_out+, and Current Sensor 5A 1
• - connected to Bridge Rectifier source_out- and Current Sensor 5A 2

AC Supply

• -ve connected to Power Transformer (220V to 24V) 2 - Primary
• +ve connected to Power Transformer (220V to 24V) 1 - Primary

Code Documentation

ESP32 Code

/*
 * This Arduino Sketch is designed for an ESP32 microcontroller to read and 
 * display voltage and current measurements from a voltage sensor and a 
 * current sensor, respectively. The voltage sensor is connected to GPIO34 
 * (D34) and the current sensor is connected to GPIO32 (D32). The code 
 * initializes the sensors, reads the analog values, converts them to 
 * meaningful voltage and current values, and prints the results to the 
 * Serial Monitor.
 */

const int voltagePin = 34;  // Voltage sensor connected to GPIO34 (D34)
const int currentPin = 32;  // Current sensor connected to GPIO32 (D32)

// Constants for sensor calibration (you may need to adjust these)
const float voltageConversionFactor = 3.3 / 4095.0;  // ESP32 ADC conversion
const float currentConversionFactor = 3.3 / 4095.0;  // Same for current sensor

// ACS712 characteristics
const float zeroCurrentVoltage = 2.5;  // The voltage at 0A for ACS712
const float currentSensitivity = 0.185; // The sensitivity for ACS712

void setup() {
  Serial.begin(115200);
  pinMode(voltagePin, INPUT);  // Set voltage sensor pin as input
  pinMode(currentPin, INPUT);  // Set current sensor pin as input
}

void loop() {
  // Read the raw analog values from the voltage and current sensors
  int voltageRaw = analogRead(voltagePin);
  int currentRaw = analogRead(currentPin);

  // Convert the raw readings to voltage
  float voltage = voltageRaw * voltageConversionFactor;  // Voltage in Volts

  // Convert the raw current readings to current (for ACS712)
  float currentVoltage = currentRaw * currentConversionFactor;  // Current sensor voltage
  float current = (currentVoltage - zeroCurrentVoltage) / currentSensitivity;  // Current in Amperes

  // Output the results to the Serial Monitor
  Serial.print("Voltage: ");
  Serial.print(voltage, 2);  // Print voltage with 2 decimal places
  Serial.print(" V | ");

  Serial.print("Current: ");
  Serial.print(current, 2);  // Print current with 2 decimal places
  Serial.println(" A");

  delay(1000);  // Wait for 1 second before taking the next reading
}

AC Supply Code

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}

Documentation File

This documentation provides a comprehensive overview of the circuit, including the components used, their wiring details, and the code running on the microcontroller.