How to Use pzem-004t: Examples, Pinouts, and Specs

The PZEM-004T is a digital power meter designed for monitoring and measuring key electrical parameters in AC circuits. It provides real-time data on voltage, current, power, energy consumption, and frequency. This module is equipped with a serial communication interface, making it easy to integrate with microcontrollers such as the Arduino UNO (manufacturer part ID: UNO). Its compact design and high accuracy make it ideal for applications in energy monitoring, home automation, industrial systems, and power management.

• Energy monitoring in residential and industrial environments
• Smart home automation systems
• Power consumption analysis for appliances
• Integration with IoT platforms for remote monitoring
• Overload protection and energy efficiency optimization

The following table outlines the key technical details of the PZEM-004T module:

The PZEM-004T module has a 4-pin interface for power and communication. The pin configuration is as follows:

To use the PZEM-004T with an Arduino UNO, follow these steps:

1. Wiring:

   • Connect the VCC pin of the PZEM-004T to the 5V pin on the Arduino UNO.
   • Connect the GND pin of the PZEM-004T to the GND pin on the Arduino UNO.
   • Connect the RX pin of the PZEM-004T to the TX pin (pin 1) on the Arduino UNO.
   • Connect the TX pin of the PZEM-004T to the RX pin (pin 0) on the Arduino UNO.
   • Ensure the current transformer (CT) is properly connected to the PZEM-004T for current measurement.

2. Install Required Libraries:

   • Download and install the PZEM004T library from the Arduino Library Manager or GitHub.

3. Upload Code: Use the following example code to read data from the PZEM-004T:

   #include <PZEM004T.h> // Include the PZEM-004T library
   
   // Define the RX and TX pins for the PZEM-004T
   #define RX_PIN 0
   #define TX_PIN 1
   
   // Create a PZEM object
   PZEM004T pzem(RX_PIN, TX_PIN);
   
   void setup() {
       Serial.begin(9600); // Initialize serial communication
       Serial.println("PZEM-004T Power Meter Example");
   }
   
   void loop() {
       // Read voltage
       float voltage = pzem.voltage();
       if (voltage != NAN) {
           Serial.print("Voltage: ");
           Serial.print(voltage);
           Serial.println(" V");
       } else {
           Serial.println("Error reading voltage!");
       }
   
       // Read current
       float current = pzem.current();
       if (current != NAN) {
           Serial.print("Current: ");
           Serial.print(current);
           Serial.println(" A");
       } else {
           Serial.println("Error reading current!");
       }
   
       // Read power
       float power = pzem.power();
       if (power != NAN) {
           Serial.print("Power: ");
           Serial.print(power);
           Serial.println(" W");
       } else {
           Serial.println("Error reading power!");
       }
   
       // Read energy
       float energy = pzem.energy();
       if (energy != NAN) {
           Serial.print("Energy: ");
           Serial.print(energy);
           Serial.println(" kWh");
       } else {
           Serial.println("Error reading energy!");
       }
   
       // Wait for 1 second before the next reading
       delay(1000);
   }
   

• Ensure the PZEM-004T is connected to an AC circuit within its specified voltage and current range.
• Use proper insulation and safety precautions when working with high-voltage AC circuits.
• Avoid reversing the RX and TX connections, as this will prevent communication with the Arduino.
• The current transformer (CT) must be clamped around only one conductor (live or neutral) for accurate current measurement.

1. No Data Output:

   • Verify the RX and TX connections between the PZEM-004T and the Arduino UNO.
   • Ensure the baud rate in the code matches the module's default baud rate (9600 bps).
   • Check the power supply to the PZEM-004T module.

2. Incorrect Readings:

   • Ensure the current transformer (CT) is properly connected and clamped around a single conductor.
   • Verify that the AC voltage and current are within the module's specified range.

3. Communication Errors:

   • Check for loose or incorrect wiring.
   • Ensure no other devices are using the same serial pins on the Arduino UNO.

Q: Can the PZEM-004T measure DC circuits?
A: No, the PZEM-004T is designed specifically for AC circuits and cannot measure DC voltage or current.

Q: Can I use the PZEM-004T with a 3.3V microcontroller?
A: Yes, the PZEM-004T's serial interface is compatible with both 3.3V and 5V logic levels.

Q: How do I reset the energy reading to zero?
A: The energy reading can be reset using a specific command sent via the serial interface. Refer to the module's datasheet for details.

Q: What is the maximum cable length for the current transformer?
A: The cable length should be kept as short as possible to minimize signal loss and ensure accurate readings.