In all 256M Raspberry Pi models, the I2C user port is 0, and in rest, all it is 1.Īfter enabling the I2C user port, the connected I2C slaves can be detected using i2c-tools. Note that in the older versions of Raspberry Pi, the I2C user port is identified as I2C0 instead of I2C1. I2C1 must appear as one of the Linux devices available as shown in the image below. In the Terminal window, run the following command: Now reboot Raspberry Pi by entering the following command:Īfter rebooting, GPIO3 and GPIO5 can be used to connect Raspberry Pi as I2C master with an I2C bus or to any I2C slave.Īfter enabling I2C user-port and rebooting Raspberry Pi, we can test if the port is available as a Linux device or not. In the pop-up window, enable the Arm I2C interface and select ‘Yes’ to load the I2C Kernel Module. In older Raspberry Pi models, navigate to ‘Advanced Options’ and then ‘I2C’.
#Raspberry pi interfaces file software
In the Raspberry Pi Software Configuration Tool, navigate to ‘Interfacing Options’. Open Terminal and run the following command: The I2C support for Raspberry Pi’s ARM core and Linux Kernel can also be enabled from the Terminal (Bash Shell on Raspberry Pi). After rebooting, GPIO3 and GPIO5 can be used to connect Raspberry Pi as I2C master with an I2C bus or to any I2C slave. To take changes effect, restart Raspberry Pi. You can also enable or disable other interfaces as required. In the pop-up window, click on the ‘Interfaces’ tab and select the ‘Enable’ radio button for I2C. On Raspbian, navigate to Pi Start Menu -> Preferences -> Raspberry Pi Configuration. Therefore, I2C1 is sufficient to connect several I2C slaves (maximum 112 slaves) and any number of master devices. The Raspberry Pi’s BSC controllers support multi-master, multi-slave I2C. It needs to be enabled from the Raspberry Pi configuration. While using I2C0, pins avoid using the HAT EEPROM address.Įven the I2C1 is disabled on Raspberry Pi by default. The I2C0 pins are not internally pulled up, so if they are used by modifying the Raspberry Pi configuration file, external pull-ups (to 3.3V) must be used on both SDA and SCL lines. To use I2C0, add the following lines to boot/config.txt. It is possible to access I2C0 only if both the camera interface and HDMI port are unused. I2C0 can only talk to HAT EEPROM at address 0x50 during boot time. I2C0 remains reserved for reading EEPROM of Raspberry Pi’s add-on boards called Hardware on The Top (HAT) boards. This I2C interface is present at board pins 27 (ID_SD) and 28 (ID_SC). The BSC2 master is dedicated to the HDMI interface and cannot be accessed by users. There is one more I2C peripheral BSC2 in Raspberry Pi identified as I2C0. That is why these pins cannot be used for general-purpose I/O where pull-up is not required. These I2C pins are internally pulled up to 3.3V via 1.8 kohms resistors.
#Raspberry pi interfaces file serial
GPIO2 is Serial Data (SDA) line, and GPIO3 is a Serial Clock (SCL) line of the I2C1. This I2C interface is accessible at pins GPIO2 (Board Pin No. The BSC controller supports both 7-bit as well as 10-bit addressing. This standard-mode master BSC controller is NXP Semiconductor’s I2C compliant and supports a data transfer rate of 400 kbps. In this tutorial, we will discuss serial communication in Raspberry Pi using the I2C protocol.įor serial communication over the I2C protocol, the Broadcom processor of Raspberry Pi has Broadcom Serial Controller (BSC). In most of the embedded devices, either UART otherwise I2C is used for console messages. Open a plaintext editor such as Notepad (Windows) or TextEdit (Mac) and create a new file.In the previous tutorial, we discussed the basics of the I2C protocol.