Ask Hackaday: Can We Get Someone To Buy And Destroy RAM?

We like blinky things. We’re moths drawn to the flame of serially-addressable RGB LEDs. If the LEDs are smaller, we want to know. If you can drive more of them, we want to know. That said, the most interesting news out of CES last January was both right up our alley, and immensely disappointing. Corsair, makers of RGB computer fans, RGB CPU coolers, and RGB keyboards and mice, have a new product out: RGB RAM, because professional gamers and streamers have a higher win percentage when their RAM is illuminated.

The key innovation of the new Corsair Dominator Platinum RGB DDR4 DRAM is called, ‘Capellix LEDs’. The press surrounding these LEDs gives a clear advantage: right now, the RGB LEDs in your gaming system are mounted in a large SMD package, like a WS2812 or APA101. These large packages reduce LED density, and making LEDs smaller means moar RGB — more colors, or brighter colors, or better efficiency. The key advancement in Capellix LEDs is taking the guts of a serially addressable RGB LED and putting it in a smaller package. Instead of a package that’s 2.8mm³ in volume, the Capellix LED is ‘just 0.2mm³ in size’. The few pictures available of these LEDs give the impression they’re about the size of an 0805 package. It’s small, and we’d like to get our hands on some.

Where these LEDs come from is anyone’s guess, but Corsair did partner with Primax, a Taiwanese manufacturer of computer peripherals, to pull this off. There is no mention of Capellix LEDs in Primax’s press releases, and we don’t actually know if these are the smallest serially addressable RGB LEDs available; we don’t even know if they’re serially addressable. There could easily be a small microcontroller in the Corsair Dominator Platinum RGB DDR4 DRAM, as each stick is only driving twelve individually controllable RGB LEDs.

The bottom line is, someone needs to spend $160 for 16GB of RAM, then tear the whole thing apart, preferably with close-up pics of the fancy new RGB LEDs.

A cynical reader would say that Capellix LEDs are simply existing LEDs, the name ‘Capellix’ was trademarked by Corsair, and these LEDs were shoved into a stick of RAM with a significant markup. This, surprisingly, is demonstrably wrong because there is no entry for ‘Capellix’ in the United States Patent and Trademark Office Trademark Electronic Search System. That doesn’t mean the spirit of the cynic is wrong, though; ROHM semiconductors just released a new side-view RGB LED that might be smaller than Corsair’s Capellix LEDs. There are, of course, RGB LEDs available in similar sizes, but none of these are serially-addressable like a WS2812 or APA101. We don’t know what’s in these fancy sticks of RAM, but we’re waiting for someone to do a tear down so we can find out.

Ten 3D Printed Gadgets That Just Can’t Stay Still

There was a time, not so very long ago, when simply getting a 3D printer to squirt out an object that was roughly the intended shape and size of what the user saw on their computer screen was an accomplishment. But like every other technology, the state of the art has moved forward. Today the printers are better, and the software to drive them is more capable and intuitive. It was this evolution of desktop 3D printing that inspired the recently concluded 3D Printed Gears, Pulleys, and Cams contest. We wanted to see what hackers and makers can pull off with today’s 3D printing tools, and the community rose to the challenge.

Let’s take a look at the top ten spinning, walking, flapping, and cranking 3D printed designs that shook us up:

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Hack My House: Raspberry Pi As A Touchscreen Thermostat

Your thermostat is some of the oldest and simplest automation in your home. For years these were one-temperature setting and nothing more. Programmable thermostats brought more control; they’re alarm clocks attached to your furnace. Then Nest came along and added beautiful design and “learning features” that felt like magic compared to the old systems. But we can have a lot more fun. I’m taking my favorite single-board computer, the Raspberry Pi, and naming it keeper of heat (and cool) by building my own touchscreen thermostat.

Mercury thermostats started it all, and were ingenious in their simplicity — a glass capsule containing mercury, attached to a wound bi-metal strip. As the temperature changes, the contraption tilts and the mercury bead moves, making or breaking contact with the wiring. More sophisticated thermostats have replaced the mercury bead with electronics, but the signaling method remains the same, just a simple contact switch.

This makes the thermostat the prime target for an aspiring home automation hacker. I’ve had this particular project in mind for quite some time, and was excited to dive into it with simple raw materials: my Raspberry Pi, a touchscreen, and a mechanical relay board.

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Simple Timer Evolves Into Custom Kid’s Watch

Sporting a new wristwatch to school for the first time is a great moment in a kid’s life. When it’s a custom digital-analog watch made by your dad, it’s another thing altogether.

As [Chris O’Riley] relates, the watch he built for his son [Vlad] started out as a simple timer for daily toothbrushing, a chore to which any busy lad pays short shrift unless given the proper incentive. That morphed into an idea for a general purpose analog timepiece with LEDs taking the place of hands. [Chris] decided that five-minute resolution was enough for a nine-year-old, which greatly reduced the number of LEDs needed. An ATtiny841 tells a 28-channel I2C driver which LEDs to light up, and an RTC chip keeps [Vlad] on schedule. The beautiful PCB lives inside a CNC machined aluminum case; we actually commented to [Chris] that the acrylic prototype looked great by itself, but [Vlad] wanted metal. The watch has no external buttons; rather, the slightly flexible polycarbonate crystal bears against a PCB-mounted pushbutton to control functions.

With a snappy wristband, [Vlad] will be rolling fancy on the schoolyard. It’s a great looking piece that needed a wide range of skills to execute, as all watches do. Check out some other watch builds, like this lovely pure analog, another digital-analog hybrid, or this pocket watch that packs an Enigma machine inside.

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Multiple OLEDs? Save Pins By Sharing The I2C Clock

Inexpensive OLED displays with I2C interfaces abound, but there is a catch: they tend to be stuck on I2C address 0x3C. Some have a jumper or solder pads to select an alternate (usually 0x3D), but they lack any other method. Since an I2C bus expects every device to have a unique address, this limits the number of displays per bus to one (or two, at best.) That is all still true, but what [Larry Bank] discovered is a way to get multiple OLED displays working with considerably fewer microcontroller pins than usually needed.

While bit-banging I2C to host one display per bus on the same microcontroller, an idea occurred to him. The I2C start signal requires both clock (SCL) and data (SDA) to be brought low together, but what would happen if the displays shared a single clock line? To be clear, each OLED would — logically speaking — still be on its own I2C bus with its own data line, but they would share a clock signal. Would a shared clock cause attached devices to activate unintentionally?

A quick test consisting of four OLED displays (all with address 0x3C) showed that it was indeed possible to address each display with no interference if they shared a clock. Those four individually controlled displays needed only five I/O lines (four SDA, one shared SCL) instead of eight. The Multi_OLED library is available on GitHub, and in case it is useful for devices other than OLED displays, bit-banged I2C with support for shared clock lines is available separately.

There’s more to do with OLEDs than get clever with signals: check out these slick number-change animations, and that even looks to be a project that could benefit from a few saved GPIO pins, since it uses one small display per digit.