{"id":1004,"date":"2025-09-25T04:54:53","date_gmt":"2025-09-25T00:54:53","guid":{"rendered":"https:\/\/seriyps.com\/blog\/?p=1004"},"modified":"2025-10-03T22:25:39","modified_gmt":"2025-10-03T20:25:39","slug":"pair-ina226-and-raspberry-pi-ina2xx-kernel-driver","status":"publish","type":"post","link":"https:\/\/seriyps.com\/blog\/2025\/09\/25\/pair-ina226-and-raspberry-pi-ina2xx-kernel-driver\/","title":{"rendered":"How to pair INA226 current and voltage sensor and Raspberry Pi using ina2xx kernel driver"},"content":{"rendered":"\n

INA226<\/a> is a popular microchip to measure the voltage and power consumption that uses i2c digital interface. There are a lot of articles describing how to make it work with Arduino, much fewer about how it can be connected and read using generic Linux i2c tools and seems to be none explaining how can it be paired with Linux ina2xx kernel driver<\/a> so it can be manipulated via hwmon subsystem. Let’s fix ths!<\/p>\n\n\n\n\n\n\n\n

In this example we are going to:<\/p>\n\n\n\n

    \n
  1. Enable i2c interface in Raspberry Pi OS<\/li>\n\n\n\n
  2. Connect INA226 breakout board<\/a> to Raspberry Pi zero 2w<\/a><\/li>\n\n\n\n
  3. Create and enable a custom Device Tree overlay for OS to recognize the sensor<\/li>\n\n\n\n
  4. Explore the sysfs entries provided by ina2xx kernel driver<\/li>\n<\/ol>\n\n\n\n

    Enable i2c interface<\/h2>\n\n\n\n

    In Raspberry Pi OS (Debian) i2c interface is disabled by-default, so we obviously need to enable it first. To do that, open the shell on Raspberry and run<\/p>\n\n\n\n

    sudo raspi config<\/code><\/pre>\n\n\n\n
    In UI select “3 Interface Options”<\/p>\n\n\n\n
    \"\"<\/a><\/figure>\n\n\n\n
    then I5 I2C<\/p>\n\n\n\n
    \"\"<\/a><\/figure>\n\n\n\n
    And in the next screen select “yes”<\/p>\n\n\n\n
    \"\"<\/a><\/figure>\n\n\n\n
    When done, you should be able to see at least 2 i2c devices:<\/p>\n\n\n\n
    $ ls \/dev\/i2c*\n\/dev\/i2c-1  \/dev\/i2c-2<\/code><\/pre>\n\n\n\n
    One of them is system internal, but i2c-1<\/code> is the one that is accessible via the GPIO pins 3 and 5<\/a>.<\/p>\n\n\n\n
    You can now install the tools to inspect the i2c on Linux:<\/p>\n\n\n\n
    sudo apt install i2c-tools<\/code><\/pre>\n\n\n\n
    And try to see if there are any devices connected to i2c bus:<\/p>\n\n\n\n
    $ sudo i2cdetect -y 1\n     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f\n00:                         -- -- -- -- -- -- -- -- \n10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- \n20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- \n30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- \n40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- \n50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- \n60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- \n70: -- -- -- -- -- -- -- --<\/code><\/pre>\n\n\n\n
    If it looks this way, it means no devices are connected which is expected.<\/p>\n\n\n\n
    Connecting the INA226 brealout board<\/h2>\n\n\n\n
    The board we are going to use looks like this:<\/p>\n\n\n\n
    \"\"<\/a><\/figure>\n\n\n\n
    it has the shunt resistor that says “R100” which means 0,1 Ohm<\/a> and it has following outputs:<\/p>\n\n\n\n