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I2C Guide

Use this guide to scan an I2C bus, detect devices, and perform basic reads/writes on the Omega4.

1. Prerequisites​

  • Firmware with I2C enabled (Omega4 support starts at v0.0.7).
  • i2c-tools package.

Install tools if needed:

opkg update
opkg install i2c-tools

2. Find the I2C bus​

List available I2C devices:

ls /dev/i2c-*

Check bus numbers and adapter names:

i2cdetect -l

3. Scan for devices​

Replace <bus> with your bus number:

i2cdetect -y <bus>

You should see 7-bit addresses for attached devices.

4. Read/write quick tests​

Read a single register:

i2cget -y <bus> 0x50 0x00

Write a single register:

i2cset -y <bus> 0x50 0x00 0x01

5. Troubleshooting​

  • No /dev/i2c-*: confirm the device tree enables the I2C controller and pinmux for the EVB header.
  • Remote I/O error: check wiring, device address, and pull-up resistors.
  • Bus hangs after a test: power-cycle the peripheral and retry the scan.