Would you do with a massive full color animated LED display? How about…
- Read your Tweets in giant 140 char gulps from a block away
- Add English sub-titles to the Eiffel Tower
- Display a live-updating, 45 digit long countdown of the number of atoms left in the known universe
What if you could build the display however long you needed it, for only about $15/foot?
What if it was really easy to build and used everyone’s favorite low cost micro-controller so you could easily change the software to do whatever you wanted?
Well you can! Read on for details and perfunctory video!
We’ve already seen that it is possible to drive thousands of WS2812B NeoPixels with a lowly Arduino using careful bit-banging. But what if we could bang out 8 bits at a time rather than sending them single file? Could it be possible to drive 8 times as many strings (or get 8 times the refresh rate) from our Arduino by processing bits in parallel? It would be like having a tiny pipelined GPU render engine inside our Arduino!
Read on to find out the results of a quick proof-of-concept test!….
Making a smart color-changing light bulb is not that hard, but making one that is cheap to mass produce is hard. At $10 per bulb (delivered!), the new GE C-Sleep bulbs are amazingly cheap, especially considering they include a Bluetooth radio.
For Part #1, let’s look at the physical design and construction of these fancy bulbs!
But what about capacitive power transmission?
How come I’ve never seen a product that uses plates rather than coils? Is capacitive power transfer possible? Practical? Let’s break out a roll of tinfoil and find out!
It can be nice to know how much battery power you have. It becomes critically important with LiPo batteries since you can permanently damage them by running the voltage down too low. Typically battery voltage detection requires adding a circuit with extra parts and their associated power requirements. Wouldn’t it be great to be able to do this using nothing but software? Read on for a no parts, no pins, no power solution…
Last time, we connected a NeoPixel directly to a RaspberryPi. This is certainly fun and useful, but the real motivation behind this project was to explore clever ways to make use of limited hardware resources. NeoPixels need a precisely timed string of bits to be happy. Luckily, every RaspPi comes with built-in hardware for generating strings of precisely timed bits – a serial port!
If all you care about is making pretty colors the easy way, don’t bother reading this article. If you are wondering how it is possible to reliably generate a pulse train with +/-150ns precision on a Raspberry Pi pin without kernel mods or DMA, then read on!