DevHeads IoT Integration ServerDIIS
DevHeads IoT Integration Server•2y ago
Boss lady

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.
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;
}


@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-0
crw-rw---- 1 root gpio 89, 1 May 17 12:23 /dev/i2c-1
crw-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 group.

First thing to try is therefore running you program with 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 gpio group.
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