As a rule, the enjoyable a part of placing collectively a Raspberry Pi mission—or any microelectronics mission for that matter—is figuring out the logistics of what interfaces you want and peripherals to incorporate. Typically it takes ingenuity to carry the whole lot collectively and that is demonstrated fairly effectively on this HDMI to I2C mission by maker and developer Solaria123.
The concept to attach a tool that depends on an I2C interface to the DDC pins discovered inside an unused video port isn’t new. Nevertheless, we nonetheless recognize this mission because it demonstrates the compatibility and suppleness of the Raspberry Pi. In line with Solaria123, this trick is used usually with Linux-based machines that don’t have any I2C gadgets.
On this case, the hack is helpful for conditions by which I2C pin entry has been blocked by both a case or one thing like a module. So long as the HDMI port is free, DDC is able to offering a low-speed I2C bus of 80 KHz.
On this demo, Solaria is utilizing a Raspberry Pi 4 however there’s no purpose this couldn’t work on a 3B+ mannequin or perhaps a Pi Zero. There could also be some tweaking wanted to get the setup excellent on different fashions however the potential is unquestionably there. Within the instance, Solaria is controlling an Adafruit Bi-Colo 24-bar bargraph module by means of the HDMI port with the assistance of an Adafruit HDMI breakout.
Due to its low pace, customers are restricted to what they’ll management and may solely use this methodology for primary I2C interface calls for. That stated, you’ve bought 50mA of 5V to play with so there’s loads of wiggle room for experimentation. To get a better take a look at the Python code that makes this doable, take a look at the mission web page shared over at Github.
If you wish to recreate this Raspberry Pi mission or develop one thing comparable, go to the unique thread shared to Reddit to get a greater concept of the way it all goes collectively. You can even comply with Solaria123 for extra cool initiatives in addition to any future updates on this one.
