Enable I2C, I2s, SPI in boot-config file?
#4
Hi,

starting with the info given in the post KnReLe, i write a little app in C++ that uses i2c0 bus. This works but requires the app to be executed as root. As i'm not a linux expert, i were looking for a solution and find the following so that this i2c bus could be used all the time outside root:

  1. create a user group (for instance i2cuser) and add rock64 (my user account) to the group 
       $sudo addgroup i2cuser   $sudo usermod -a -G i2cuser rock64
  2. create a script /usr/local/sbin/i2c0add.sh :
    Code:
    #!/bin/bash
    #script to add i2c-0 to the devices
    echo Create /dev/i2c-0
    enable_dtoverlay i2c0 i2c@ff150000 okay
    #change owner:group of /dev/i2c-0
    chown root:i2cuser /dev/i2c-0


  3. create a systemd service file /etc/systemd/system/i2c0add.service :
    Code:
    [Unit]
    Description=Service to create i2c0 device
    After=sockets.target

    [Service]
    Type=oneshot
    RemainAfterExit=no
    ExecStart=/usr/local/sbin/i2c0add.sh

    [Install]
    WantedBy=multi-user.target


  4. enable the execution of the service at startup:
      $sudo systemctl enable /etc/systemd/system/i2c0add.service
I hope that i did not forget something. I not sure that this is the best solution but this works.
In addition, linux version is 18.04 LTS (Bionic Beaver)
I am also looking for a solution for using the gpio lines as non root, but until now without success. 
If someone has a solution....



Regards


Messages In This Thread
RE: Enable I2C, I2s, SPI in boot-config file? - by pas059 - 08-14-2018, 10:59 AM

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