The Word Clock You Can Feel

By this point, pretty much everyone has come across a word clock project, if not built one themselves. There’s just an appeal to looking at a clock and seeing the time in a more human form than mere digits on a face. But there are senses beyond sight. Have you ever heard a word clock? Have you ever felt a word clock? These are questions to which Hackaday’s own [Moritz Sivers] can now answer yes, because he’s gone through the extreme learning process involved in designing and building a haptic word clock driven with the power of magnets.

Individual letters of the display are actuated by a matrix of magnetic coils on custom PCBs. These work in a vaguely similar fashion to LED matrices, except they generate magnetic fields that can push or pull on a magnet instead of generating light. As such, there are a variety of different challenges to be tackled: from coil design, to driving the increased power consumption, to even considering how coils interact with their neighbors. Inspired by research on other haptic displays, [Moritz] used ferrous foil to make the magnets latch into place. This way, each letter will stay in its forward or back position without powering the coil to hold it there. Plus the letter remains more stable while nearby coils are activated.

Part of the fun of “ubiquitous” projects like word clocks is seeing how creative hackers can get to make their own creations stand out. Whether it’s a miniaturized version of classic designs or something simple and clean, we  love to see them all. Unsurprisingly, [Moritz] himself has impressed us with his unique take on word clocks in the past. (Editor’s note: that’s nothing compared to his cloud chambers!)

Check out the video below to see this display’s actuation in action. We’re absolutely in love with the satisfying *click* the magnets make as they latch into place.

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Android Flip Dot Display

Controlling A Flip-Disc Display Using Android

There’s just something about electro-mechanical displays that enthralls most people when they see them; and while you’ll be hard pressed to find a split-flap display for cheap, you can still easily buy flip-disc displays! That’s what [Scott] did, and he’s been having a blast messing around with his and building a system to control it via his Android phone.

He picked up the display from a company called Alfa-Zeta in Poland, a company that’s been making electromagnetic displays since 1988. No mention of price, but it looks like some pretty awesome hardware. The beauty with electromagnetic displays is they don’t consume any electricity in idle state, making them far more efficient than almost any other display technology – not to mention perfect contrast in any lighting conditions!

They work by using permanent magnets, electromagnets, and a material that can retain magnetization. A short pulse to the electromagnet causes the disc to flip into the second position, which will then hold in place due to the permanent magnet — no more electromagnet needed.

The display comes with all the necessary hardware to drive the electromagnets and interface with a microcontroller. But, it uses the RS-485 standard, which isn’t natively supported by most other microcontrollers. [Scott’s] using an Arduino which does have an RS-485 shield, but he decided he wanted to challenge himself and build a circuit to drive them himself!

All the info is on his blog if you’re looking to try something similar. Once he had it interfaced with the Arduino it was just a simple matter of writing an Android app to transmit controls over Bluetooth for the display. Take a look:

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