from the solution-looking-for-a-problem dept.
[janrinok:] We covered a story a few months ago regarding a watch that also contained a projector which could be used to show an enlarged image on any nearby surface, including the hand that is wearing the watch. Well somebody decided to look a little more closely at making his own small projector - although not quite to the same degree of miniaturisation.
Who doesn’t want a pocket projector? Nothing will impress a date more than being able to whip out a PowerPoint presentation of your latest trip to the comic book convention. The key to [MickMake] build is the $100 DLP2000EVM evaluation module from Texas Instruments. This is an inexpensive light engine, and perfect for rolling your own projector. You can see the result in the video below.
If you don’t need compactness, you could drive the module with any Rasberry Pi or even a regular computer. But to get that pocket form factor, a Pi Zero W fits the bill. A custom PCB from [MickMake] lets the board fit in with the DLP module in a very small form factor. DLP chips use lots of microscopic mirrors that you can move roughly 20 degrees under computer control. So you can reflect light into the lens or bounce it away so it makes the image black. For color, an RGB LED cycles through the primary colors and you have to time your mirror movements to the color you want to project. Of course, the module takes care of all this for you behind the scenes.
The module can output up to 30 lumens (by default, though, it is 20 lumens) and has I2C and 8/16/24-bit parallel RGB video interfaces. If you don’t want to go with a custom board, the device supports the BeagleBone Black right out of the box. The DLP resolution is nHD. That is the mirror array is 640×360. While you might think the “n” stands for not, it actually stands for ninth, as in one-ninth. The current release of the adapter board lacks an audio amplifier, although that may change in a future release. For now, you can play audio from the Pi via Bluetooth.
The nice thing about smartwatches is that they put information right on your wrist so it's easy to check. But what if that information was even more visible? What if that information was right on the back of your hand?
That question, I can only assume, is what led to the creation of Haier's Asu watch, an enormous smartwatch with a built-in projector. The projector allows the watch to display information on the back of your hand, essentially serving as a second screen.
Haier uses the projection to provide additional information. So when you're running, the projection will display distance, time, and progress toward fitness goals, while the watch screen will have controls to pause and finish your workout. The projection actually supports gesture controls, too: you can double tap on your hand to change what's on the screen. It didn't work very well when I tried it, but Haier says the whole watch is still in development.