A HVTPI adapter plugged into a USBASP, with a an IDC10 cable plugged into it in turn

HVTPI Primer And Toolkit Equips You For BOM Substitutions

Novel programming interfaces for MCUs might catch us by surprise, but then we inevitably get up to speed with the changes required. Today’s bastion is HVTPI – a “12V reset” addition to the TPI we’ve just started getting used to, and [Sam Ettinger] has shared a simple circuit to teach us all about it, along with PCB files and detailed explanations of how it all works.

HVTPI is an add-on on top of TPI, for which, as Sam explains, you need to hold RST at 12V when TPI would have it be low logic level, and leave it at Vtarget otherwise. For that, he has designed a variety of interposer boards of various complexity and requirements; explaining the choices behind each one and clearing up any misunderstandings that might occur on your way. All of the board files (and the TPI write-up copy) are caringly shared with us in a git repository, too! As a result, if you have an USB-ASP or an Arduino available, now you also have everything to do HVTPI, thanks to Sam’s work and explanations.

We’ve been covering Sam’s exploits before, and can’t help but be grateful for the stop-and-explain detour along the way. HVTPI being used on very small ATTiny parts, we wonder if something new in the vein of his recent FPC board able to fit and function entirely within a Type-C cable end!

With chip shortages, investigating programming interfaces for small and obscure yet in-stock microcontrollers has been, quite literally, paying off, and if you got some projects that need a MCU but won’t consume a whole lot of resources, it could be time to give an ATTiny10 a go. What’s the worst that can happen – you make the smallest chiptunes ever?

Tiny LED Earrings Are A Miniaturization Tour De Force

Light up jewelry is nothing new – we see wearables all the time here. But home brew, self-contained, programmable LED earrings that are barely larger than the watch batteries which power them? That’s something worth looking into.

assembly5Settle back and watch [mitxela]’s miniature wizardry in the video below, but be forewarned: it runs 36 minutes. Most of the video is necessarily shot through a microscope where giant fingers come perilously close to soldering iron and razor blade.

The heart of the project is an ATtiny9, a six-legged flea of a chip. The flexible PCB is fabricated from Pyralux, which is essentially copper-clad Kapton tape. [Mitxela] etched the board after removing spray-paint resist with a laser engraver – an interesting process in its own right.

After some ridiculously tedious soldering, the whole circuit wraps around a CR927 battery and goes into a custom aluminum and polypropylene case, which required some delicate turning. Hung from off-the-shelf ear hooks, the 12 multiplexed LEDs flash fetchingly and are sure to attract attention, especially of those who know Morse.

This isn’t exactly [mitxela]’s first tiny rodeo, of course. We’ve featured his work many times, including a Morse code USB keyboardthe world’s smallest MIDI synthesizer, and the world’s smallest MIDI synthesizer again.

Continue reading “Tiny LED Earrings Are A Miniaturization Tour De Force”

Breaking Out The ATtiny10

Atmel’s ATtiny10 is the one microcontroller in their portfolio that earns its name. It doesn’t have a lot of Flash – only 1 kilobyte. It doesn’t have a lot of RAM – only thirty two bytes. It is, however, very, very small. Atmel stuffed this tiny microcontroller into an SOT-23 package, more commonly used for surface mount transistors. It’s small, and unless your ideal application is losing this chip in your carpet, you’re going to need a breakout board. [Dan] has just the solution. He could have made this breakout board smaller, but OSHpark has a minimum size limit. Yes, this chip is very, very small.

Because this chip is so small, it doesn’t use the normal in-system programming port of its larger brethren. The ATtiny10 uses the Tiny Programming Interface, or TPI, which only requires power, ground, data, clock, and a reset pin. Connecting these pins to the proper programming header is easy enough, and with a careful layout, [Dan] fit everything into a breakout board that’s a hair smaller than a normal 8-pin DIP.

The board works perfectly, but simply soldering the ATtiny10 to a breakout board and using it as is probably isn’t the best idea. The reason you use such a small microcontroller is to put a microcontroller into something really, really small like ridiculous LED cufflinks. A breakout board is much too large for a project like this, but SOT23 test adapters exist, and they’re only $25 or so.

Either way, [Dan] now has a very, very small microcontroller board that can fit just about anywhere. There’s a lot you can do with one kilobyte of Flash, and with an easy way to program these chips, we can’t wait to see what [Dan] comes up with.

Making Chiptunes With 32 Bytes Of RAM

Ah, chiptunes. One of the few remaining human endeavours where less RAM, less storage space, and fewer capabilities are actually considered an improvement. [dop3joe] over at the Stuttgart hackerspace Shackspace sent in a tiny chiptune playing circuit using the most bare-bones hardware we’ve ever seen.

The Noiseplug, as [dop3joe] calls it, is based on a very, very small 6 pin ATtiny9. With 1 kB of Flash memory and only 32 bytes of RAM [dop3joe] was able to create a small device inside an RCA jack that plays chiptunes whenever it is powered by a battery.

If you’d like to make your own noise plug, [dop3j0e] put all the code up in his Git. There are two relevant pieces of software for this build: a Windows app to create the chiptunes, and the ATtiny9 firmware itself. Of course to program the tiny, you’ll have to deal with the Atmel TPI, so here’s the application note (PDF).

Oh, [dop3joe] won third place at the Evoke demoscene party last weekend with the Noiseplug. Awesome.