A software-based I2C master-only implementation for Arduino and compatible microcontrollers (ESP8266, ESP32).
This library provides a lightweight, master-only I2C driver that uses a software-based implementation to emulate the I2C protocol. It is ideal for projects that need an additional I2C bus on Arduino boards and is also compatible with ESP8266 and ESP32 microcontrollers.
- Software-based I2C Master: Implements the I2C protocol entirely in software without using the hardware I2C peripherals.
- Master-only Functionality: Supports fundamental I2C operations such as start, stop, write, and read.
- Multi-platform Support: Works with Arduino (AVR-based), ESP8266, and ESP32.
- Lightweight & Easy-to-use: Simple API with functions similar to standard I2C libraries.
- MIT Licensed: Free to use, modify, and distribute in your projects.
- Download or clone the repository.
- Copy the
I2C.handI2C.cppfiles into your Arduino libraries folder (typically~/Documents/Arduino/libraries/).
- Download the repository as a ZIP file.
- In the Arduino IDE, go to Sketch → Include Library → Add .ZIP Library....
- Select the downloaded ZIP file.
Below is a basic example to demonstrate how to use the library:
#include "I2C.h"
// Define SDA and SCL pins (adjust according to your board)
#define SDA_PIN 4
#define SCL_PIN 5
I2C myI2C(SDA_PIN, SCL_PIN);
void setup() {
// Initialize serial communication for debugging
Serial.begin(9600);
// Initialize the I2C bus
myI2C.begin();
// Begin transmission to a device at address 0x50 (example)
if (myI2C.beginTransmission(0x50)) {
// Write a single byte of data
byte data = 0xAA;
myI2C.write(data);
// End transmission
myI2C.endTransmission();
}
// Request 2 bytes from the device at address 0x50
myI2C.requestFrom(0x50, 2);
// Read and print received bytes
while (myI2C.available()) {
byte received = myI2C.read();
Serial.println(received, HEX);
}
}
void loop() {
// Your main code here
}
-
begin()
Initializes the I2C bus by setting up the SDA and SCL pins. -
beginTransmission(byte addr)
Begins a transmission to the device with the specified address. -
endTransmission()
Ends the current transmission and releases the I2C bus. -
requestFrom(byte addr, size_t len)
Requests a specified number of bytes from the I2C device. -
read()
Reads a byte from the receive buffer. -
write(byte data)
Sends a single byte to the I2C device. -
*write(byte data, size_t len)
Sends multiple bytes to the I2C device. -
available()
Returns the number of bytes available to be read from the buffer. -
flush()
Clears the receive buffer.
Contributions are welcome! Feel free to open issues or submit pull requests on GitHub to help improve the library.
This project is licensed under the MIT License. See the LICENSE file for more details.