In the world of hardware hackers, sometimes you spend a lot of time debugging a problem, but find a simple solution is always in front of you. [Zack Freedman] has a good understanding of this when making Optigon V2. Optigon is an improved Epson Moverio wearable display, which he uses as a teleprompter in all videos. He prefers to place the teleprompter above his left eye, but if one of them is disconnected, the new version of Moverio will cut off the connection on both sides, so (Zack) needs a workaround.
In order to seek the above help, [Zack] asked Epson for the developer documentation of the display module, but was rejected because he was not a manufacturer or product developer. Fortunately, the specification sheet that can be downloaded from Epson’s website does contain a lot of information he needs. STM32 monitors the temperature of each display module through a pair of independent I2C interfaces. If any of them cannot be connected, all devices will be shut down. This causes [Zack] to try to cheat the I2C signal with ATmega328, but it cannot keep up with the 400 kHz I2C bus.
However, by checking the log of the logic analyzer, [Zack] found that STM32 never talked to two display modules at the same time, although it can do this. Both displays use the same I2C address, so [Zack] can simply use a simple interface board to connect the two I2C buses, effectively making the left display “cheat” the signal of the right display.
Wearable displays need some fancy optical elements to be practical. You can’t just stick OLEDs on your face. Two other interesting projects of [Zack] are his modular mechanical keyboard and Gridfinity 3D printing storage system.