Open Hardware Monitor Data Display with ESP8266

This project allows an ESP8266 (ESP-12E) microcontroller to retrieve system performance metrics such as CPU and GPU temperatures and loads from the Open Hardware Monitor Web API and display them in real-time on a 16x2 I2C LCD. It's a lightweight and efficient solution for creating a hardware monitoring dashboard.

Features

• Connects to a Wi-Fi network to retrieve hardware monitoring data from a web server.
• Parses JSON data from the Open Hardware Monitor API.
• Displays CPU and GPU temperatures and loads on a 16x2 I2C LCD screen.
• Automatically retries in case of Wi-Fi disconnection.

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Requirements

1. Hardware:

   • ESP8266 (ESP-12E or compatible board)
   • I2C 16x2 LCD Display
   • Power source for the ESP8266

2. Software:

   • Arduino IDE (with ESP8266 Board Package)
   • Required Arduino Libraries:
     • ESP8266WiFi
     • Wire
     • LiquidCrystal_I2C
     • ArduinoJson
     • ESP8266HTTPClient

3. Open Hardware Monitor:

   • Download and install Open Hardware Monitor.
   • Enable the web server API in the software (default port: 8085).

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Wiring

Connect the I2C LCD display to the ESP8266 as follows:

LCD Pin	ESP8266 Pin
VCC	VIN
GND	GND
SDA	D2
SCL	D1

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Installation

1. Clone or download this repository to your local machine.
2. Open the .ino file in Arduino IDE.
3. Update the following placeholders in the code:

   const char* ssid = "";       // Your Wi-Fi SSID
   const char* password = "";   // Your Wi-Fi Password
   const char* serverName = "http://192.168.0.104:8085/data.json"; // Replace with your Open Hardware Monitor server IP

4. Install required libraries in the Arduino IDE:
   • Go to Tools > Manage Libraries, search for each library name, and install it.
5. Upload the code to your ESP8266 board.

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Usage

1. Start the Open Hardware Monitor application on your computer.
2. Ensure the ESP8266 and the computer are on the same Wi-Fi network.
3. Power up the ESP8266. It will:
   • Connect to the Wi-Fi network.
   • Fetch hardware data from the Open Hardware Monitor API every 2 seconds.
   • Display CPU and GPU statistics on the LCD.

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Code Structure

Global Variables

• Wi-Fi Credentials: ssid and password.
• API Server: serverName (URL to the Open Hardware Monitor data).
• LCD Setup: LiquidCrystal_I2C lcd initializes the I2C LCD.
• Fetch Timing: fetchInterval controls the API data fetch frequency.

Main Functions

• setup():
  • Initializes the LCD and Wi-Fi connection.
  • Displays IP address upon successful connection.
• loop():
  • Periodically fetches data from the API.
• fetchData():
  • Sends an HTTP GET request to the API server.
  • Calls parseAndDisplayData() to process and display the response.
• parseAndDisplayData():
  • Parses the JSON response and extracts CPU/GPU temperatures and loads.
  • Displays data on the LCD.
• reconnectWiFi():
  • Reconnects to Wi-Fi if the connection is lost.
• getSubstring():
  • Extracts a substring up to a specific delimiter.

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Sample Output on LCD

CPU: 55C° 40%
GPU: 60C° 70%

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Troubleshooting

1. Wi-Fi Connection Issues:

   • Verify SSID and password.
   • Ensure the ESP8266 and computer are on the same network.

2. No Data on LCD:

   • Check the Open Hardware Monitor web server status.
   • Verify the API server IP in the code.

3. JSON Parsing Error:

   • Confirm that the Open Hardware Monitor JSON structure matches the code.

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License

This project is open-source and available under the MIT License. Feel free to modify and use it for personal projects.