How can I interface an I2C device with BeagleBone Black running Embedded Linux
Hello guys, how can I interface an I2C device with BeagleBone Black running Embedded Linux for my home automation system?. I have connected the I2C device to the appropriate pins on the BeagleBone Black, enabled the I2C interface on the BeagleBone Black, wrote a C program to communicate with the I2C device using the I2C bus. But keep encountering
Failed to open the I2C bus.
Failed to open the I2C bus.
this is my code
#include <stdio.h>#include <stdlib.h>#include <fcntl.h>#include <unistd.h>#include <linux/i2c-dev.h>int main() { int i2cFile; // Open the I2C bus i2cFile = open("/dev/i2c-1", O_RDWR); if (i2cFile < 0) { printf("Failed to open the I2C bus.\n"); return -1; } // Set the slave address int slaveAddress = 0x12; if (ioctl(i2cFile, I2C_SLAVE, slaveAddress) < 0) { printf("Failed to set slave address.\n"); return -1; } // Perform I2C communication // ... // Close the I2C bus close(i2cFile); return 0;}
#include <stdio.h>#include <stdlib.h>#include <fcntl.h>#include <unistd.h>#include <linux/i2c-dev.h>int main() { int i2cFile; // Open the I2C bus i2cFile = open("/dev/i2c-1", O_RDWR); if (i2cFile < 0) { printf("Failed to open the I2C bus.\n"); return -1; } // Set the slave address int slaveAddress = 0x12; if (ioctl(i2cFile, I2C_SLAVE, slaveAddress) < 0) { printf("Failed to set slave address.\n"); return -1; } // Perform I2C communication // ... // Close the I2C bus close(i2cFile); return 0;}
@Middleware & OS
Solution
@Boss lady if the devices exist, then the next thing I would check are the permissions. Having just taken a quick look on mine...
debian@BeagleBone:~$ ls -l /dev/i2c-*crw-rw---- 1 root gpio 89, 0 May 17 12:23 /dev/i2c-0crw-rw---- 1 root gpio 89, 1 May 17 12:23 /dev/i2c-1crw-rw---- 1 root gpio 89, 2 May 17 12:23 /dev/i2c-2
debian@BeagleBone:~$ ls -l /dev/i2c-*crw-rw---- 1 root gpio 89, 0 May 17 12:23 /dev/i2c-0crw-rw---- 1 root gpio 89, 1 May 17 12:23 /dev/i2c-1crw-rw---- 1 root gpio 89, 2 May 17 12:23 /dev/i2c-2
Then that shows me they are only readable by the root user and anyone belonging to the
gpio
gpio
group.
First thing to try is therefore running you program with
sudo
sudo
. If that works, then it is likely to be a permission issue. If it works, then the simplest solution would be to add yourself to the