1. Introduction
In this article, we will provide a comprehensive guide on how to use the i2c command in Linux. The i2c command allows communication with devices connected through the I2C bus, a popular serial communication protocol used for connecting sensors, displays, and other low-speed peripherals to microcontrollers and microprocessors. We will explore the various features and options of the i2c command, and provide detailed examples for better understanding.
2. Installing the i2c Tools
Before using the i2c command, we need to ensure that the i2c-tools package is installed on our Linux system. To install it, open a terminal and execute the following command:
sudo apt-get install i2c-toolsOnce the installation is complete, we can proceed with using the i2c command.
3. Discovering I2C Devices
3.1 Listing Available I2C Buses
The i2c command provides the i2cdetect tool, which allows us to scan for I2C devices connected to the system. To list available I2C buses, execute the following command:
i2cdetect -lThis command will display a list of available I2C buses along with their corresponding adapter numbers.
3.2 Detecting I2C Devices
To detect the I2C devices connected to a specific bus, we can use the i2cdetect command followed by the bus number. For example, to detect devices on bus 1, run the following command:
i2cdetect -y 1This command will display a grid showing the I2C device addresses in hexadecimal format. If a device is detected at a specific address, that address will be shown in the grid.
4. Communicating with I2C Devices
4.1 Reading from an I2C Device
To read data from an I2C device, we can use the i2cget command. This command requires the bus number, device address, and register address as arguments. For example, to read a byte of data from device 0x50 on bus 1, with register address 0x00, use the following command:
i2cget -y 1 0x50 0x00This command will output the byte of data read from the specified register of the device.
4.2 Writing to an I2C Device
To write data to an I2C device, we can use the i2cset command. Similar to i2cget, this command requires the bus number, device address, register address, and data to be written as arguments. For example, to write the byte 0x42 to register 0x00 of device 0x50 on bus 1, use the following command:
i2cset -y 1 0x50 0x00 0x42This command will write the specified data to the specified register of the device.
5. Additional Options
The i2c command provides various additional options for advanced usage. Some of the important options include:
5.1 Setting the I2C Bus Frequency
By default, the i2c bus operates at 100 kHz. However, this can be changed using the -y option followed by the desired frequency. For example, to set the bus frequency to 400 kHz, use the following command:
i2cdetect -y -r 4005.2 Specifying a Different I2C Adapter
In case there are multiple I2C adapters available, we can specify a different adapter using the -a option followed by the adapter number. For example, to use adapter number 2, use the following command:
i2cdetect -y -a 25.3 Using a Different I2C Address Size
The i2cdetect command assumes a 7-bit device address size by default. However, if the I2C device uses a different address size, we can specify it using the -r option followed by the desired address size. For example, to detect devices with a 10-bit address size, use the following command:
i2cdetect -y -r 106. Conclusion
In this article, we explored the capability of the i2c command in Linux and provided a comprehensive guide on how to use it. We covered the process of discovering I2C devices, as well as reading from and writing to them using the i2cget and i2cset commands. Additionally, we discussed the various options available for advanced usage of the i2c command.
Knowing how to use the i2c command is essential for interacting with I2C devices on Linux systems, and this guide will serve as a valuable resource for developers and enthusiasts working with I2C communication.