The Three Cent Motor Controller

If you follow the world of small microcontrollers you will certainly be familiar with the usual fare of Atmel, ARM Cortex, PIC, and others. But these aren’t the smallest or cheapest devices, below them is an entire category of grain-of-dust microcontrollers with minimal capabilities and at rock bottom prices. Maybe the most well known are the Padauk series of chips, whose PIC12-like architecture can be had for literal pennies. These are the famous 3 cent microcontrollers, but despite their fame they have a bit of a reputation in our community for being difficult to work with. [Ben Lim] dispels some of those ideas, by Padauk-enabling a motor and encoder from a printer to make a three cent motor controller.

The Padauk doesn’t have on-chip peripherals such as SPI, instead its IDE provides bit-banging code to do the job. This and some PID motor controller code makes for a straightforward task on the little chip, and with the help of a probably considerably more expensive MAX14870 it can drive the motor. For the curious, the code can be found in a Git Hub repository. There may be more accomplished motor controllers to be found, but we doubt you’ll find one with a cheaper microcontroller.

Want to know what the fuss is about with the Padauk? Our colleague [Maya Posch] has you covered.

Hands-On: Whiskey Pirates DC29 Hardware Badge Blings With RISC-V

The Whiskey Pirates have once again dropped an excellent electronic badge for DEF CON 29. This is, of course, unofficial, but certainly makes the list of the hottest custom bling seen so far this year.

I’m not able to make it to the con in person, but the Pirates sent over one of these badges anyway for an early look. It’s gorgeous, and peering into the circuit board it would be easy to think that the chip shortage ain’t got nothin’ on this badge. But this was possible only because of some very creative parts sourcing, and a huge dose of inspired design work.

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RCA Plug Plays Sixteen-Minute Chiptune Piece, All By Itself

Frequenters of arcades back in the golden age of video games will likely recall the mix of sounds coming from a properly full arcade, the kind where you stacked your quarters on a machine to stake your claim on being next in line to play. They were raucous places, filled with the simple but compelling sounds that accompanied the phosphor and silicon magic unfolding all around.

The days of such simple soundtracks may be gone, but they’re certainly not forgotten, with this chiptunes generator built into an RCA plug being both an homage to the genre and a wonderful example of optimization and miniaturization. It’s the work of [girst] and it came to life as an attempt to implement [Rob Miles]’ Bitshift Variations in C Minor algorithmically generated chiptunes composition in hardware. For the first attempt, [girst] chose an ATtiny4 as the microcontroller, put it and the SMD components needed for a low-pass filter on a flex PCB, and wrapped the whole thing around a button cell battery. Stuffed into the shell of an RCA plug, the generator detects when it has been inserted into an audio input jack and starts the 16-minute piece. [girst] built a second version, too, using the Padauk PSM150c “Three-Cent Microcontroller” chip.

This is quite an achievement in chiptunes minimization. We’ve seen chiptunes in 32 bytes, Altoids tin chiptunes, and an EP on a postage-stamp-sized PCB, but this one might beat them all on size alone.

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Hackaday Podcast 068: Picky Feeders, Slaggy Tables, Wheelie Droids, And Janky Batteries

Hackaday editors Elliot Williams and Mike Szczys ride the rails of hackerdom, exploring the sweetest hacks of the past week. There’s a dead simple component feeder for a pick and place (or any bench that hand-stuffs SMD), batteries for any accomplished mixologist, and a droid build that’s every bit as cool as its Star Wars origins. Plus we gab about obsolescence in the auto industry, fawn over a frugal microcontroller, and ogle some old iron.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

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Ultra-Cheap Microcontroller Powers Addressable 7-segment Display

Since their being revealed to our community over a year ago, the various ultra-cheap microcontrollers in the sub-ten-cent price range have attracted a lot of interest but not so many projects. Their slightly annoying programming and PIC12-derived architectures present a barrier not mitigated by their price, when picking up an Atmel or other processor represents a much easier choice. That’s not to say that they aren’t slowly making an appearance though, and a cracking example comes from [Tim], who’s used a Padauk microcontroller to make an addressable 7-segment display. If you’re used to addressable multi-colour LEDs, this extends the idea into the world of numerical information.

The result is a PCB little bigger than the 7-segment display it serves, with interlocking 0.1″ pin connectors allowing daisy-chaining of modules. The extreme low cost of the parts makes it an attractive solution. Software wise it’s driven in a similar manner to addressable LEDs, and he goes into significant detail on its protocol. The firmware can be found in a GitHub repository. He directs readers to the Easy PDK programmer and the Small Device C compiler, which should be of interest to anyone tempted by these processors.

Hackaday Podcast 035: LED Cubes Taking Over, Ada Vanquishes C Bugs, Rad Monitoring Is Hot, And 3D Printing Goes Full 3D

Hackaday Editors Mike Szczys and Elliot Williams get caught up on the most interesting hacks of the past week. On this episode we take a deep dive into radiation-monitor projects, both Geiger tube and scintillator based, as well as LED cube projects that pack pixels onto six PCBs with parts counts reaching into the tens of thousands. In the 3D printing world we want non-planar printing to be the next big thing. Padauk microcontrollers are small, cheap, and do things in really interesting ways if you don’t mind embracing the ecosystem. And what’s the best way to read a water meter with a microcontroller?

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

Continue reading “Hackaday Podcast 035: LED Cubes Taking Over, Ada Vanquishes C Bugs, Rad Monitoring Is Hot, And 3D Printing Goes Full 3D”

Everything You Wanted To Know About Padauk MCUs And More

At this point you’d need to have lived underneath a rock somewhere on the dark side of the Moon to not have heard about these amazing, 3-cent microcontrollers. A number of places have pitched in on them, but comprehensive reviews, let alone a full-blown review of the entire ecosystem surrounding these Padauk MCUs have been scarce. Fortunately, [Jay Carlson] has put in a lot of effort to collect everything you could possibly want to know about anything Padauk.

The most important take-away is that these MCUs do not have any kind of communication peripherals. UARTs, I2C, and SPI all have to be done in software. They’re not very great at low-power or battery-powered applications due to high power usage. Essentially you’ll be using GPIO pins a lot. On the other hand, its multi-CPU context, FPPA feature is rather interesting, with the article covering it in detail.

As for the development tools, [Jay] came away very impressed with the In-Circuit Emulation (ICE) instead of running code on an MCU, as this can reduce development times significantly. This makes even the OTP (one-time programmable) property of most Padauk MCUs less significant than one might at first assume.

Then there’s the actual programming of the MCUs. The Micro C compiler Padauk provides essentially implements a sub-set of the C language, with some macros to replace things like for loops. Initially this may seem like a weird limitation, until you realize that these MCUs have 64 to 256 bytes of SRAM. That’s bytes, without any prefixes.

Finally, [Jay] shows off a couple of test projects, including a NeoPixel SPI adapter and bike light, which are all available on Github. The WS2812b project is something we have seen before, for example this project from [Anders Nielsen] (featured in the article image), which provides another take on this range of MCUs.

Did reading [Jay]’s article change your mind on these Padauk parts? Have you used these MCUs and ICE parts before? Feel free to leave your thoughts in the comments.