Building a Smart Power Meter with ESP8266

Building a Power Meter using ESP8266 and INA226 Current Sensor

Hardware Requirements

• ESP8266 microcontroller (VMOS D1 mini)
• INA226 current sensor
• DHT11 temperature and humidity sensor
• 0.96 inch OLED display
• SMD resistors and capacitors
• Female headers
• 100 amp shunt

Software Requirements

The code for this project was built using ESP Home, a popular framework for building IoT projects. The code is available in the description below and can be flashed onto the ESP8266 microcontroller.

Project Overview

This project allows for the measurement of current up to 100A and voltage up to 100VDC, as well as temperature and humidity readings. The INA226 current sensor is capable of measuring negative current, making it suitable for a wide range of applications.

The power meter also features a 0.96 inch OLED display, which shows the measured values in real-time. The project can be integrated with Home Assistant, allowing users to view the readings wirelessly.

PCB Design and Manufacturing

The PCB design for this project was created using a CAD software and converted into Gerber files. The files were then uploaded to JLCPCV, a popular online PCB manufacturing service.

JLCPCV offers a convenient and cost-effective way to manufacture PCBs in small quantities. The service allows users to select the quantity of PCBs they want to order, with higher quantities resulting in lower prices per unit.

Assembly and Testing

Once the PCBs arrived, the components were assembled onto the board. The code was then flashed onto the ESP8266 microcontroller, and the power meter was tested to ensure that it was working as expected.

Potential Applications

This power meter can be used in a wide range of applications, including capacity testing of lithium-ion phosphate batteries. The ability to measure negative current makes it suitable for use with batteries that have a built-in battery management system (BMS).

Additionally, the power meter's compact size and wireless connectivity make it an ideal solution for IoT projects where space is limited.

Future Improvements

This project is still in its early stages, and there are many potential improvements that can be made. Some possible areas for improvement include:

• Adding more sensors to measure additional parameters such as temperature and humidity
• Improving the user interface to make it easier to use and understand
• Increasing the accuracy of the measurements

Conclusion

This project demonstrates the potential for building a compact and accurate power meter using an ESP8266 microcontroller and an INA226 current sensor. With its ability to measure negative current and integrate with Home Assistant, this power meter is suitable for use in a wide range of applications.

Building a Smart Power Meter with ESP8266

In this article, we will explore how to build a smart power meter using the popular ESP8266 microcontroller. The smart power meter will be able to measure and monitor the electrical power consumption of a household or office in real-time, and send the data to a cloud server for further analysis and visualization.

Components Required

• ESP8266 microcontroller (e.g. NodeMCU board)
• Current Transformer (CT) sensor
• Voltage Sensor (e.g. ZMPT101B)
• Breadboard and jumper wires
• Power supply (e.g. USB cable)

Circuit Diagram

The circuit diagram shows the connections between the ESP8266, CT sensor, voltage sensor, and power supply. The CT sensor is connected to the current-carrying wire of the electrical circuit being monitored. The voltage sensor is connected across the voltage terminals of the electrical circuit.

Software Components

• Arduino IDE (for programming the ESP8266)
• ESP8266 library (for WiFi and HTTP communication)
• ThingSpeak library (for cloud data logging)

Programming the ESP8266

The ESP8266 is programmed using the Arduino IDE. The program reads the current and voltage values from the sensors, calculates the power consumption, and sends the data to a ThingSpeak channel for cloud logging.

        // Import libraries
        #include <WiFi.h>
        #include <ThingSpeak.h>

        // Define constants
        const char* ssid = "your_wifi_ssid";
        const char* password = "your_wifi_password";

        // Initialize variables
        float current, voltage, power;

        void setup() {
          Serial.begin(115200);
          WiFi.begin(ssid, password);
          while (WiFi.status() != WL_CONNECTED) {
            delay(1000);
            Serial.println("Connecting to WiFi...");
          }
          Serial.println("Connected to WiFi");
          ThingSpeak.begin(WiFi.client);
        }

        void loop() {
          // Read current and voltage values
          current = analogRead(A0);
          voltage = analogRead(A1);

          // Calculate power consumption
          power = current * voltage;

          // Send data to ThingSpeak channel
          ThingSpeak.setField(1, power);
          ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
          delay(10000); // Wait 10 seconds before sending next reading
        }
      

ThingSpeak Configuration

Create a new ThingSpeak channel and configure it to receive data from the ESP8266. You will need to create an API key for writing data to the channel.

Conclusion

In this article, we have shown how to build a smart power meter using the ESP8266 microcontroller. The system measures current and voltage values from sensors and sends the calculated power consumption data to a ThingSpeak channel for cloud logging.