Often the fun part of building is raspberry pi The project, or any microelectronics project for that matter, is looking at the logistics of the required interfaces and peripherals to include. It may take some ingenuity to put everything together. HDMI to I2C Project by maker and developer Solaria123.
The idea of connecting a device that relies on an I2C interface to a DDC pin inside an unused video port is not new. However, we continue to appreciate this project as it demonstrates the compatibility and flexibility of the Raspberry Pi. According to Solaria123, this trick is often used on Linux-based machines that don’t have I2C devices.
In this case the hack is useful in situations where I2C pin access is blocked by something like a case or module. As long as the HDMI port is free, the DDC can provide a slow I2C bus of 80 KHz.
In this demo, Solaria uses a Raspberry Pi 4, but there’s no reason this shouldn’t work on a 3B+ model or even a Pi Zero. Other models may require some tweaking to get the setup right, but the potential is definitely there. In this example, Solaria utilizes the Adafruit HDMI breakout to control the Adafruit Bi-Colo 24 bar bargraph module through the HDMI port.
Due to its slow speed, users are limited to what they can control and should only use this method for basic I2C interface requests. That said, 5V he can play with 50mA, so there’s plenty of room for experimentation. For a closer look at the Python code that makes this possible, check out the project page shared at: github.
If you want to reproduce this raspberry pi project Or to develop something similar, visit the original thread shared reddit To better understand how everything works together. You can also follow Solaria123 for more cool projects and future updates to this project.