CH32V003 Makes For Dirt Cheap RISC-V Computer

May 31, 2024 by Tom Nardi 35 Comments

These days, when most folks think of a computer they imagine a machine with multiple CPUs, several gigabytes of RAM, and a few terabytes of non-volatile storage for good measure. With such modern expectations, it can be difficult to see something like a microcontroller as little more than a toy. But if said MCU has a keyboard, is hooked up to a display, and lets you run basic productivity and development software, doesn’t that qualify it as a computer? It certainly would have in the 1980s.

With that in mind, [Olimex] has teased the RVPC, which they’re calling the “world lowest cost Open Source Hardware All-in-one educational RISC-V computer” (say that three times fast). The tiny board features the SOIC-8 variant of the CH32V003 and…well, not a whole lot else. You’ve got a handful of passives, a buzzer, an LED, and the connectors for a PS/2 keyboard, a power supply, and a VGA display. The idea is to offer this as a beginner’s soldering kit in the future, so most most of the components are through-hole.

On the software side, the post references things like the ch32v003fun development stack, and the PicoRVD programmer as examples of open source tools that can get your CH32V computer up and running. There’s even a selection of retro-style games out there that would be playable on the platform. But what [Olimex] really has their eye on is a port of VMON, a RISC-V monitor program.

When paired with the 320×200 VGA text mode that they figure the hardware is capable of, you’ve got yourself the makings of an educational tool that would be great for learning assembly and playing around with bare metal programming.

It might not have the timeless style of the Voja4, but at least you can fit it in a normal sized pocket.

Thanks to [PPJ] for the tip.

CH32V003 Provides Ultra Cheap Speech Recognition

May 30, 2024 by Jenny List 6 Comments

Speech recognition was once the stuff of science fiction, but it’s now possible with relatively modest hardware. Just how modest, you ask? How about a 10 cent microcontroller?

[Brian Smith] has achieved a very basic form of speech recognition on a CH32V003 RISC-V microcontroller. It may only recognize spoken digits, but that it does so at all on such a modest platform is impressive in itself.

For training purposes it enlists the help of a desktop Linux computer, however the recognition process is purely in the ten cent chip. He goes into much detail about how it achieves this on a system without floating point arithmetic, as well as the other shortcomings of such a limited platform.

We’ve become used to thinking of super-cheap chips as of limited use, but the truth is they’re surprisingly more capable than expected. We’re seeing them starting to appear as subsidiary processors on some badges, so it will be interesting to see them proliferate in more projects now their availability problems have eased. Go on – for ten cents, what do you have to lose?

Pixel Graphics From An HD44780, By Cutting Wires

May 29, 2024 by Elliot Williams 11 Comments

[Felipe Tavares] wasn’t satisfied with the boring default fonts on an HD44780-based display. And while you can play some clever tricks with user-defined characters, if you want to treat the display as an array of pixels, you’ve got to get out your scalpel and cut up a data line.

The hack builds on work from [MisterHW] who documented the bits going from the common display driver to the display, and suggested that by cutting the data line and sending your own bits, you could send arbitrary graphics. The trick was to make sure that they’re in sync with the display, though, which means reading the frame sync line in user code.

This done, it looks like [Felipe] has it working! If you can read Rust for the ESP32, he has even provided us with a working demo of the code that makes it work.

We can’t help but wonder if it’s not possible to go even lower-level and omit the HD44780 entirely. Has anyone tried driving one of these little LCD displays directly from a microcontroller, essentially implementing the HD44780 yourself?

Any way you slice it, this is a cool hack, and it opens up the doors to DOOM, or as [MisterHW] suggests, Bad Apple on these little displays . If you do it, we want to see it.

If your needs aren’t so exotic, the classic HD44780 display is a piece of cake to get working, and an invaluable tool in anyone’s toolbox.

Adafruit Badges Turned Electronic Invitations

May 28, 2024 by Tom Nardi 8 Comments

Despite what you might have heard, even the most devout Hackaday readers may eventually find themselves getting married. Should you ever find yourself in a situation where you need to send out invitations for your big day, or any other major celebration for that matter, you could do worse than follow the example [Mokas] and their partner set with these memorable electronic wedding invitations.

Inspired by the electronic badges distributed at hacker cons, [Mokas] decided to use Adafruit’ EdgeBadge and PyBadge devices to create a similar interactive keepsake that would be a bit more exciting than a piece of paper. While it would have been enough to have the wedding information pop up on the screen when they were turned on, the final invites actually boot into a retro-style game where you walk around talking to characters to uncover information about the event and the venue.

The game was created in Microsoft MakeCode Arcade, with a sprinkling of original and commissioned sprites. Early versions of the game ended up being a bit much for the Adafruit badge’s to handle, but after doing a bit of research on creating games for computationally-constrained platforms, [Mokas] was able to optimize the performance. For those that didn’t get a physical invite (no doubt ours was simply lost in the mail), you can play the whole thing right in your browser.

It’s a very clever idea, and while using custom hardware would have allowed for a more bespoke package, we can’t blame [Mokas] for wanting to keep this one simple. Getting everything ready for your wedding is already enough stress — it’s hardly the time to spin up a new board.

For a similar reasons, another Adafruit offering was selected to power the couple’s e-ink baby development display.

A System Board For The 8008

May 27, 2024 by Bryan Cockfield 27 Comments

Intel processors, at least for PCs, are ubiquitous and have been for decades. Even beyond the chips specifically built by Intel, other companies have used their instruction set to build chips, including AMD and VIA, for nearly as long. They’re so common the shorthand “x86” is used for most of these processors, after Intel’s convention of naming their processors with an “-86” suffix since the 1970s. Not all of their processors share this convention, though, but you’ll have to go even further back in time to find one. [Mark] has brought one into the modern age and is showing off his system board for this 8008 processor.

The 8008 predates any x86 processor by about six years and was among the first mass-produced 8-bit processors even before the well-known 8080. The expansion from four bits to eight was massive for the time and allowed a much wider range of applications for embedded systems and early personal computers. [Mark] goes into some of the details for programming these antique processors before demonstrating his system board. It gets power from a USB-C connection and uses a set of regulators and level shifters to make sure the voltages all match. Support for all the functions the 8008 needs is courtesy of an STM32. That includes the system memory.

For those looking to develop something like this, [Mark] has also added his development tools to a separate GitHub page. Although it’s always a good idea for those interested in computer science to take a look at old processors like these, it’s not always the easiest path to get original hardware like this, which also carries the risk of letting smoke out of delicate components. A much easier route is to spin up an emulator like an 8086 IBM PC emulator on an ESP32. Want to see inside this old chip? Have a look.

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The Long Road Towards Reverse Engineering The ESP32 Wi-Fi Driver

May 27, 2024 by Maya Posch 15 Comments

Although much of the software that runs on the ESP32 microcontroller is open source, the Wi-Fi driver is not. Instead, it uses a proprietary binary blob. This was no problem for [Jasper Devreker]’s reverse-engineering of the ESP32’s Wi-Fi stack so far until he came face to face with reverse-engineering the initialization of the Wi-Fi peripheral. As it turns out, there is a lot of work involved after you call esp_phy_enable in the Espressif binary blob, with the team logging 53,286 peripheral accesses during the initialization phase. In comparison, sending a Wi-Fi packet takes about ten calls.

Currently, the way that the initialization step is handled is by having the initialization routine in the binary blob do its thing by configuring the radio and other elements before killing the FreeRTOS task and replacing it with their own version. The team is actively looking for a clean approach for moving forward that will avoid simply writing everything from scratch. For the Wi-Fi MAC, existing code (e.g., FreeBSD’s stack) could be used, but the radio code is much more of a headache. Clearly, there’s still a lot more work to be done in order to get a fully open-source Wi-Fi MAC and stack for the ESP32, but having the community (that’s you) pitch in might speed things up if there’s demand for an open-source driver.

[Jasper’s] been working on this for a while. He’s even built a Faraday cage to make the task easier.

Is This The World’s Smallest Multichannel Voltmeter?

May 22, 2024 by Jenny List 8 Comments

The instrument which probably the greatest number of Hackaday readers own is likely to be the humble digital multimeter. They’re cheap and useful, but they’re single-channel, and difficult to incorporate into a breadboard project. If you’ve ever been vexed by these limitations then [Alun Morris] has just the project for you, in the world’s smallest auto-ranging multichannel voltmeter. It’s a meter on a tiny PCB with a little OLED display, and as its name suggests, it can keep an eye on several voltages for you.

At its heart is an ATtiny1614 microcontroller on a custom PCB, but for us the part we most like lies not in that but in the prototype version made on a piece of protoboard. There’s considerable soldering skill in bending surface mount components to your will on this material, and though these aren’t quite the smallest parts it’s still something that must have required some work under the magnifier.

All of the code and hardware details can be found in the GitHub repository, and for your viewing pleasure there’s a video showing it in action which we’ve placed below.

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