M.2 Makes An Unusual Microcontroller Form Factor

November 3, 2024 by Jenny List 36 Comments

When we think of an m.2 slot in our laptop or similar, it’s usually in the context of its PCI connectivity for high-speed applications such as solid state disks. It’s a connector that offers much more than that interface though, making it suitable for some unexpected add-ons. As an example [MagicWolfi] has produced an m.2 card which contains the equivalent of a Raspberry Pi Pico.

The board itself has the familiar m.2 edge connector at the bottom, and the RP2040 GPIO lines as postage-stamp indentations round the edges. On the m.2 front is uses the USB interface as well as a UART and the I²C lines, as well as some of the interfaces we’re less familiar with such as ALERT, WAKE, DISABLE1/2, LED 1/2, and VENDOR_DEFINED.

On one level this provides a handy internal microcontroller card with which you can do all the things you’d expect from a Pi Pico, but on another it provides the fascinating possibility of the Pico performing a watchdog or other function for the host device. We would be genuinely interested to hear more about the use of the m.2 slot in this way.

If you’d like to know more about m.2, we’ve taken a look at it in more depth.

An RP2040-based PC-FX Development Cartridge

November 2, 2024 by Dave Rowntree 3 Comments

[David Shadoff] has a clear soft spot for the NEC console systems and has been collecting many tools and data about them. When developing with these old systems, having a way to upload code quickly is a real bonus, hence the creation of the PC-FX Dev Cart. Based on the Raspberry Pi RP2040, the custom cartridge PCB has everything needed to run software uploadable via a USB-C connection.

While the PC-FX is a CDROM-based system, it does sport a so-called FX-BMP or backup memory port cartridge slot, which games can use to save state and perform other special functions. Under certain circumstances, the PC-FX can be instructed to boot from this memory space, and this cartridge project is intended to enable this. Having a quick way to upload and execute code is very useful when exploring how these old systems work, developing new applications, or improving the accuracy of system emulators. The original FX-BMP cartridge has little more inside than a supercapacitor-backed SRAM and a custom interfacing IC, and of course, it would be quite a hassle to use this to develop custom code.

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Use PicoGlitcher For Voltage Glitching Attacks

October 30, 2024 by Dave Rowntree 5 Comments

We see a fair few glitcher projects, especially the simpler voltage glitchers. Still, quite often due to their relative simplicity, they’re little more than a microcontroller board and a few components hanging off some wires. PicoGlitcher by Hackaday.IO user [Matthias Kesenheimer] is a simple voltage glitcher which aims to make the hardware setup a little more robust without getting caught up in the complexities of other techniques. Based on the Raspberry Pico (obviously!), the board has sufficient niceties to simplify glitching attacks in various situations, providing controllable host power if required.

A pair of 74LVC8T245 (according to the provided BoM) level shifters allow connecting to targets at voltages from 1.8 V to 5 V if powered by PicoGlitcher or anything in spec for the ‘245 if target power is being used. In addition to the expected RESET and TRIGGER signals, spare GPIOs are brought out to a header for whatever purpose is needed to control a particular attack. If a programmed reset doesn’t get the job done, the target power is provided via a TPS2041 load switch to enable cold starts. The final part of the interface is an analog input provided by an SMA connector.

The glitching signal is also brought out to an SMA connector via a pair of transistors; an IRLML2502 NMOS performs ‘low power’ glitching by momentarily connecting the glitch output to ground. This ‘crowbarring’ causes a rapid dip in supply voltage and upsets the target, hopefully in a helpful way. An IRF7807 ‘NMOS device provides a higher power option, which can handle pulse loads of up to 66A. Which transistor you select in the Findus glitching toolchain depends on the type of load connected, particularly the amount of decoupling capacitance that needs to be discharged. For boards with heavier decoupling, use the beefy IRF7807 and accept the glitch won’t be as sharp as you’d like. For other hardware, the faster, smaller device is sufficient.

The software to drive PicoGlitcher and the hardware design files for KiCAD are provided on the project GitHub page. There also appears to be an Eagle project in there. You can’t have too much hardware documentation! For the software, check out the documentation for a quick overview of how it all works and some nice examples against some targets known to be susceptible to this type of attack.

For a cheap way to glitch an STM8, you can just use a pile of wires. But for something a bit more complicated, such as a Starlink user terminal, you need something a bit more robust. Finally, voltage glitching doesn’t always work, so the next tool you can reach for is a picoEMP.

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An SAO For Hams

October 21, 2024 by Al Williams 18 Comments

Generally speaking, the Hackaday Supercon badge will always have a place for SAO (rebranded as “Supercon add-ons”), and that makes sense. We did originate them, after all. This year, though, we’ve gone all in on SAO, and, in particular, we’ve asked to see more SAOs with communication capabilities. The standard has always had an I2C bus, but few people use them. I decided I wanted to set an example and cook up a badge for Supercon. Was it hard? Yes and no. I’ll share with you a little about the board’s genesis and the issues I found. At the end, I’ll make you a special offer, if you are going to Supercon.

The Idea

The front of the SAOGNR — the SAO connector is, of course, on the back

I’ve been a ham radio operator for a very long time. In fact, July was my 47th anniversary in the radio hobby. Well, that’s not true. It was my 47th year with a license. I had been listening to shortwave long before then. So, I wanted to do something with Morse code. You don’t have to know Morse code to get a license these days, but a lot of hams enjoy it.

I set out to do a simple board that would play some Morse code messages. But that’s just another blinking light LED with a buzzer on it, too. So, naturally, I decided it would also provide Morse code output for the I2C host. That is, the SAO could be used to convert ASCII to Morse code. Sounds simple, right? Sure.

Getting Started

I wanted to use a Raspberry Pi Pico but didn’t want to violate the SAO size requirements. Luckily, there’s an RP2040-Zero module that is quite tiny and looks more or less like a normal Pico. The two big differences are plusses: they have a reset button, and instead of a normal LED, they have a WS2812b-style LED.

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Easily Program RP2040 Boards With Your Android Device

October 11, 2024 by Lewin Day 8 Comments

You could write your microcontroller code on your desktop PC, or you could do it on your laptop on the go. Or, if you want to get really portable about things, you could write your embedded code on your phone. Enter DroidScript.

Basically, DroidScript is a JavaScript and Python IDE for Android phones and tablets. Simple enough. You can use it to write apps for your phone or tablet. But its party piece? You can now also use it to program for embedded devices—namely, a range of those based on the RP2040 microcontroller. For example, the Adafruit QT-Py RP2040, the Pimoroni TinyFX, or the Pimoroni Yukon. They run MicroPython and CircuitPython, and you can program them from DroidScript. Easy.

A decade ago, this would have been a royal pain in the butt. But today? It’s easy, because the smartphones and devboards both use USB-C connectors. All you need is a regular USB-C cable and you can hook straight up to the board and burn your code.

You can get the app on the Google Play Store if you’re so inclined. We’ve seen some other neat smartphone programming projects over the years, too. Meanwhile, if you’ve found any other nifty ways to get your code on to a dev board, don’t hesitate to let us know!

Supercon 2023 – Going Into Deep Logic Waters With The Pico’s PIO And The Pi’s SMI

September 30, 2024 by Lewin Day 5 Comments

The Raspberry Pi has been around for over a decade now in various forms, and we’ve become plenty familiar with the Pi Pico in the last three years as well. Still, these devices have a great deal of potential if you know where to look. If you wade beyond the official datasheets, you might even find more than you expected.

Kumar is presently a software engineer with Google, having previously worked for Analog Devices earlier in his career. But more than that, Kumar has been doing a deep dive into maxing out the capabilities of the Raspberry Pi and the Pi Pico, and shared some great findings in an excellent talk at the 2023 Hackaday Supercon.

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Switch Your RP2040 Between 3.3 V And 1.8 V

September 30, 2024 by Arya Voronova 5 Comments

Ever want to build a RP2040 devboard that has everything you could ever want? Bad news, “everything” also means adding 1.8 V GPIO voltage support. The good news is that this write-up by [xenia] explains the process of adding a “3.3 V/1.8 V” slide switch onto your board.

Some parts are obvious, like the need to pick a flash chip that works at either voltage, for instance. Unfortunately, most of them don’t. But there’s more you’d be surprised by, like the crystal, a block where the recommended passives are tuned for 3.3 V, and you need to re-calculate them when it comes to 1.8 V operation – not great for swapping between voltages with a flick of a switch. Then, you need to adjust the bootloader to detect the voltage supplied — that’s where the fun begins, in large part. Modifying the second stage bootloader to support the flash chip being used proved to be quite a hassle, but we’re graced with a working implementation in the end.

All the details and insights laid out meticulously and to the point, well-deserved criticism of Raspberry Pi silicon and mask ROM design choices, code fully in Rust, and a success story in the end – [xenia]’s write-up has all you could wish for.

Want to learn more about the RP2040’s bootloader specifically? Then check this out — straight out of Cornell, a bootloader that’s also a self-spreading worm. Not only is it perfect for updating your entire RP2040 flock, but it also teaches you everything you could want to know about RP2040’s self-bringup process.