[FlorianH] wished to get video out working with his BeagleBone but he just couldn’t figure out how to make the kernel play ball. then a bit of motivation struck. He knew that if you plug in the official DVI cape (that’s the BeagleBone word of what you may know as a shield) the kernel immediately starts pumping out the signals he needs. So he figured out a way to spoof the cape and output video.

At boot time the kernel polls the I2C bus to see what’s connected. The DVI cape has an EEPROM which determines it. considering that the data from the EEPROM is available for download [FlorianH] grabbed the data he needed, then used an ATmega32 to stand in for the memory chip. When he got the chip speaking to the BeagleBone he was able to discover the video sync signals on his scope and he knew he was in business.

Look closely at the breadboard on the right. We love that SIL breakout board for the ATmega32. very prototype friendly!