Custom Clock Projects Time on the Ceiling

When you’re trying to sleep at night, you may roll over to check your clock or phone, but why do you have to even do that? Why can’t you just have the time projected on the ceiling in front of your closed eyes? If you just want to buy something to do this for you, the good news is that these are available, but hacker Thomas Pototschnig thought it would be more fun to create one himself, and set a goal to make is in a 50 x 50 x 50mm cube.

The basis of this projector is a 1W LED/driver, along with a minuscule 64x32 pixel LCD screen measuring only 15 x 12mm in total. This assembly is driven by an STM32F103 Arm Cortex-M3 MCU and features custom PCBs for the LCD and the projection board. While he tried to make a projection using a pair of magnifying lenses, this didn’t work very well, and instead turned to a cheap C-mount lens to take care of shaping the image on the ceiling. He also experiment ed with a much larger Sony E-mount lens, which works even if the comparatively large lens looks a bit comical set up this way.

You can find the files needed to build this device on GitHub, or the STL files for 3D-printing are also available on Thingiverse. While this is a dedicated timekeeper, one might also note that with a powerful ARM Cortex chip onboard, other more advanced uses for this type of device would also be possible.