Cutting a wearable screen in half is harder and simpler than it seems

In the world of hardware hacking, sometimes you spend a ridiculous amount of time debugging a problem, only to find a simple solution that was right in front of you all along. [Zack Freedman] got a good dose of this while building Optigon V2, a modified Epson Moverio wearable display that he uses as a teleprompter in all his videos. He prefers to have the teleprompter just above his left eye, but the newer version of Moverio would turn off both sides if one went off, so [Zack] necessary solution.

I seek help from above, [Zack] requested developer documentation for the display module from Epson but was denied because they were not the manufacturer or developer of the product. Fortunately, the spec sheet available for download from the Epson website contained much of the information he needed. The STM32 monitored the temperature of each display module via a pair of independent I2C interfaces and would shut them all down if it couldn’t connect to any. This brought [Zack] to try to fake the I2C signals with an ATmega328, but could not follow the 400kHz I2C bus.

However, looking at the logs from his logic analyzer, [Zack] they found that the STM32 never talked to both display modules at the same time, even though it was capable of doing so. Both screens use the same I2C address, so [Zack] could simply connect two I2C buses to another simple interface board, effectively making the left display “spoof” the signals from the right display.

Wearable displays need some fancy optics to be practical, you can’t just stick an OLED on your face. Two more interesting projects from [Zack] are his modular mechanical keyboard and Gridfinity 3D printed storage system.