PZEM-004T v3.0

LINKS & REFs

Arduino library for Peacefair PZEM-004T-10A and PZEM-004T-100A v3.0 Energy monitor using the ModBUS interface.

The Version 3.0 PZEM is an upgraded version of the older PZEM-004T for which you can find the library Here

Main features

• Measures Voltage, Current, Power, Energy, Power Factor and Frequency (New in Version 3.0)
• 247 unique programmable slave addresses
  • Enables multiple slaves to use the same Serial interface PZEM MultiDevice Demo (May need to use external transistors to drive multiple devices on one bus due to GPIO current limitations)
• Internal Energy counter up to 9999.99kWh

Common issues: READ FIRST BEFORE OPENING NEW ISSUE!

• Make sure the PZEM device is connected to the 230V AC power! The 5V pin only powers the optocouplers, not the actual chip.
• Make sure the 5V and GND are BOTH connected! They are essential for the optocouplers!
• If you are getting NaNs and only the TX LED is blinking, try swapping the RX/TX wires.
• Make sure you are using the correct custom address (change with PZEMChangeAddress) or you are using the default address PZEM_DEFAULT_ADDR = 0xF8 (only works for 1 device on ModBus)
• If you want to use multiple devices on the same ModBus, please set a custom address for each and use PZEMMultiDevice
• If the current is much higher than you would expect (eg. 0.5A for a 60W device), don't panic, welcome to the world of AC! You are probably dealing with a device with bad powerfactor <1. In such cases the classic P=V*I does not apply. You can read more about this here: Power Factor
• Please be safe, AC is dangerous! If you don't know what you are doing, you can die! You are responsible for your own safety.

Other features

• Over power alarm
• Energy counter reset
• CRC16 checksum
• Better, but not perfect mains isolation

The module

This module is an upgraded version of the PZEM-004T with frequency and power factor measurement features, available at the usual places. It communicates using a TTL interface over a Modbus-RTU like communication protocol but is incompatible with the older @olehs library found here: https://github.com/olehs/PZEM004T. I would like to thank @olehs for the great library which inspired me to write this one.

Manufacturer (optimistic) specifications

Function	Measuring range	Resolution	Accuracy	TODO: Realistic specifications
Voltage	80~260V	0.1V	0.5%
Current	0~10A or 0~100A*	0.01A or 0.02A*	0.5%
Active power	0~2.3kW or 0~23kW*	0.1W	0.5%
Active energy	0~9999.99kWh	1Wh	0.5%
Frequency	45~65Hz	0.1Hz	0.5%
Power factor	0.00~1.00	0.01	1%

* Using the external current transformer instead of the built in shunt

Compatibility

MCU	Hardware Serial	Software Serial	Not Tested	Examples	Notes
ATmega168			X	HardwareSerial SoftwareSerial
ATmega328 (Arduino Uno)	(:white_check_mark:)	✔️		HardwareSerial SoftwareSerial	HW Serial conflicts with Debug output. It can be used however without having any Serial Console output
ATmega2560 (Arduino Mega)	✔️	✔️		HardwareSerial SoftwareSerial
ESP8266	(:white_check_mark:)	✔️		SoftwareSerial	HW Serial conflicts with Debug output Serial
ESP32	✔️	❌		HardwareSerial	SW Serial not really needed as ESP32 has 3 HW serials with configurable pins
STM32 BluePill			X

Examples

Hardware Serial

This example uses Hardware Serial2 in order to interface with the PZEM module. Note that not all MCUs feature multiple Serial ports. It won't for example work on the Arduino Uno.

#include <PZEM004Tv30.h>

/* Hardware Serial2 is only available on certain boards.
 * For example the Arduino MEGA 2560
*/
#if defined(ESP32)
PZEM004Tv30 pzem(Serial2, 16, 17);
#else
PZEM004Tv30 pzem(Serial2);
#endif

void setup() {
    Serial.begin(115200);

    // Uncomment in order to reset the internal energy counter
    // pzem.resetEnergy();
}

void loop() {
        
    Serial.print("Custom Address:");
    Serial.println(pzem.readAddress(), HEX);

    // Read the data from the sensor
    float voltage = pzem.voltage();
    float current = pzem.current();
    float power = pzem.power();
    float energy = pzem.energy();
    float frequency = pzem.frequency();
    float pf = pzem.pf();

    // Check if the data is valid
    if(isnan(voltage)){
        Serial.println("Error reading voltage");
    } else if (isnan(current)) {
        Serial.println("Error reading current");
    } else if (isnan(power)) {
        Serial.println("Error reading power");
    } else if (isnan(energy)) {
        Serial.println("Error reading energy");
    } else if (isnan(frequency)) {
        Serial.println("Error reading frequency");
    } else if (isnan(pf)) {
        Serial.println("Error reading power factor");
    } else {

        // Print the values to the Serial console
        Serial.print("Voltage: ");      Serial.print(voltage);      Serial.println("V");
        Serial.print("Current: ");      Serial.print(current);      Serial.println("A");
        Serial.print("Power: ");        Serial.print(power);        Serial.println("W");
        Serial.print("Energy: ");       Serial.print(energy,3);     Serial.println("kWh");
        Serial.print("Frequency: ");    Serial.print(frequency, 1); Serial.println("Hz");
        Serial.print("PF: ");           Serial.println(pf);

    }

    Serial.println();
    delay(2000);
}

Output:

Custom Address:10
Voltage: 229.60V
Current: 0.10A
Power: 4.50W
Energy: 7.368kWh
Frequency: 50.0Hz
PF: 0.19

Software Serial

Using the <SoftwareSerial.h> library...

#include <PZEM004Tv30.h>
#include <SoftwareSerial.h>

/* Use software serial for the PZEM
 * Pin 11 Rx (Connects to the Tx pin on the PZEM)
 * Pin 12 Tx (Connects to the Rx pin on the PZEM)
*/

SoftwareSerial pzemSWSerial(11, 12);
PZEM004Tv30 pzem;

void setup() {
  Serial.begin(115200);
  
  pzem = PZEM004Tv30(pzemSWSerial);
}

void loop() {
         
    Serial.print("Custom Address:");
    Serial.println(pzem.readAddress(), HEX);

    // Read the data from the sensor
    float voltage = pzem.voltage();
    float current = pzem.current();
    float power = pzem.power();
    float energy = pzem.energy();
    float frequency = pzem.frequency();
    float pf = pzem.pf();

    // Check if the data is valid
    if(isnan(voltage)){
        Serial.println("Error reading voltage");
    } else if (isnan(current)) {
        Serial.println("Error reading current");
    } else if (isnan(power)) {
        Serial.println("Error reading power");
    } else if (isnan(energy)) {
        Serial.println("Error reading energy");
    } else if (isnan(frequency)) {
        Serial.println("Error reading frequency");
    } else if (isnan(pf)) {
        Serial.println("Error reading power factor");
    } else {

        // Print the values to the Serial console
        Serial.print("Voltage: ");      Serial.print(voltage);      Serial.println("V");
        Serial.print("Current: ");      Serial.print(current);      Serial.println("A");
        Serial.print("Power: ");        Serial.print(power);        Serial.println("W");
        Serial.print("Energy: ");       Serial.print(energy,3);     Serial.println("kWh");
        Serial.print("Frequency: ");    Serial.print(frequency, 1); Serial.println("Hz");
        Serial.print("PF: ");           Serial.println(pf);

    }

    Serial.println();
    delay(2000);
}

Output:

Custom Address:11
Voltage: 229.60V
Current: 0.10A
Power: 4.50W
Energy: 7.368kWh
Frequency: 50.0Hz
PF: 0.19

Links

Check LINKS & REFs page for additional DOC's and related links

Contributing

Many thanks to all the other contributors that add new features, find bugs and generally keep this project afloa.

• @mandulaj
• @FXeio
• @ste94pz
• @vortigont
• @kozfelipe

---

Thank you to @olehs for inspiring this library.