|
Split-Flap Display In an age with LCD, LED and OLED displays everywhere it can get a little boring and a nice change is to make something mechanical with moving parts. And wanted to try out to make my own simple one-panel split-flap display. The idea was to keep it simple so I skipped the ability to zero and detect what current panel. I was first thinking to show some random emoji but after a bit more thought about it I came up with the idea to use motivational posters. They have a natural two panel split with a nice image together with a short text. I made a collection of my favorite posters to fill all panels.  Mechanical design The frame is make up of two acrylic sheets held together in the corners with 4 inch distances. All acrylic parts are cut out with a laser cutter. The flaps are held in position with two rings with holes all around. This way they can move freely enough to and you get the classic flap sound. The two opposite sides are connected to each other with some acrylic that also connect it to the shaft. The material for the flaps was not as easy to find. I wanted to have something a little more flexible and not so brittle as acrylic. I settled with HDPE even it it had the downside as not being good for laser cutting. I ended up cutting the 0.8mm sheets out with a knife instead. For the graphics I used an online sticker service where you can order your own stickers. After I got them it was just a matter of as precisely as possible position everything on each flap and keep track so everything is in the correct order. Electronics The first version I made was with the cheap 28BYJ-48-5V stepper motor you can buy for a few dollars on eBay. It somewhat worked but the motor was not always strong enough and it could get stuck on some flaps. I later decided to upgrade to a stronger 5:1 Planetary Gearbox Nema 8 stepper motor. Everything is controlled from a small PCB I designed. The motor controller is an DRV8834 from Pololu. The 5V comes from AMS1117-5.0 and the micro-controller is an attiny84. The 9V battery does not last very long but it works as long as you don't press the button too often. The motor is turned off as soon as the motor stop and is not needed to keep it in position. Software Not much to say about the software. When the button is pressed the motor runs for a random long time period.          |
| Stuff | |
 |
Split Flap Display Building a split flap display. |
|
Word Clock Showing time/date with words. |
|
Hot Plate For reflow soldering. |
|
Jenkins Build Status Sign Show the nightly build status. |
|
Light Painting Stick Paint images with light. |
|
Vattenkylning Vårat vattenkylnings projekt.(Swe only) |
|
Links Some useful and cool links. |