Split-flap displays are a great, low-power way to display text to a wide audience. Compared to other display technologies like LCDs they only use energy when the characters change, but have fallen out of favor partially because of their greater mechanical complexity and also because LCD and LED technology has become so inexpensive. They still retain a loyal following though, and [Jason] is demonstrating his version which boasts high accuracy and can be 3D printed.
To get good results, one of the keys is getting the motor positioning just right. The motor sits in the center and spins the flaps around, so stopping at exactly the right point to display a certain character is critical. [Jason]’s system uses a 28BYJ stepper motor with a magnetic encoder to ensure that the correct flap is displayed. The flaps themselves are completely 3D printed, using a method which allows for two colors to be printed even if the printer is only designed for a single color. Once printed, the flaps are installed on the wheel which is the outer ring of a planetary gear set with the stepper motor sitting in the middle.
Each character in the display is housed in a printed enclosure, and for [Jason]’s project he only needs five characters, so to control the entire setup he’s using a Raspberry Pi Pico. For more characters he suggests that it is still possible to use a smaller microcontroller like the Pico but a multiplexer may be needed. Of course, displays like this are not limited to characters alone. Take a look at this display which has custom flaps to display the current weather conditions as well.
Fascinating. I do wish we could hear it in operation, though.
https://youtu.be/I1ioeuyVwIQ?is=Kaveeq8vJTb5GtXv
I even recorded it with stereo mic setup, for your pleasure
Absolute king.
If you made a flap for each doom monster…
Appreciate it and great work!
“but have fallen out of favor partially because of their greater mechanical complexity”
Their noisy. Very noisy. They are slow; even “fast” ones are slow.
“they’re”
We have a winner… congratulations. You’ve saved the world by correcting a spelling mistake.
It’s spelled correctly, just used improperly. So it’s a grammar mistake, not a spelling mistake.
… I’ll show myself to the door…
Germans are rules crazy.
Spelling is just a bunch of dumb rules.
It’s not like you’re going to do anything significant with that extra 5 seconds you save…
The slower the better ;-) As a little boy I loved watching them flip at our train station. They were boring when they were still.