Blue Pill Vs Black Pill: Transitioning From STM32F103 To STM32F411

For many years now, the so-called ‘Blue Pill’ STM32 MCU development board has been a staple in the hobbyist community. Finding its origins as an apparent Maple Mini clone, the diminutive board is easily to use in breadboard projects thanks to its dual rows of 0.1″ pin sockets. Best of all, it only costs a few bucks, even if you can only really buy it via sellers on AliExpress and EBay.

Starting last year, boards with a black soldermask and an STM32F4 Access (entry-level) series MCUs including the F401 and F411 began to appear. These boards with the nickname ‘Black Pill’ or ‘Black Pill 2’. F103 boards also existed with black soldermask for a while, so it’s confusing. The F4xx Black Pills are available via the same sources as the F103-based Blue Pill ones, for a similar price, but feature an MCU that’s considerably newer and more powerful. This raises the question of whether it makes sense at this point to switch to these new boards.

Our answer is yes, but it’s not entirely clearcut. The newer hardware is better for most purposes, really lacking only the F103’s dual ADCs. But hardware isn’t the only consideration; depending on one’s preferred framework, support may be lacking or incomplete. So let’s take a look at what it takes to switch. Continue reading “Blue Pill Vs Black Pill: Transitioning From STM32F103 To STM32F411”

PET 2001 Emulator On $2 Of Hardware

Since the late 60s, Moore’s law has predicted with precision that the number of semiconductors that will fit on a chip about doubles every two years. While this means more and more powerful computers, every year, it also means that old computers can be built on smaller and cheaper hardware. This project from [Bjoern] shows just how small, too, as he squeezes a PET 2001 onto the STM32 Blue Pill.

While the PET 2001 was an interesting computer built by Commodore this project wasn’t meant to be a faithful recreation, but rather to test the video output of the Blue Pill, with the PET emulation a secondary goal. It outputs a composite video signal which takes up a good bit of processing power, but the PET emulation still works, although it is slightly slow and isn’t optimized perfectly. [Bjoern] also wired up a working keyboard matrix as well although missed a few wire placements and made up for it in the software.

With his own home-brew software running on the $2 board, he has something interesting to display over his composite video output. While we can’t say we’d emulate an entire PC just to get experience with composite video, we’re happy to see someone did. If you’d like to see a more faithful recreation of this quirky piece of computing history, we’ve got that covered as well.

Continue reading “PET 2001 Emulator On $2 Of Hardware”

Blue Pill As A Nerdy Swiss Army Knife

Not everyone can afford an oscilloscope, and some of us can’t find a USB logic analyzer half the time. But we can usually get our hands on a microcontroller kit, which can be turned into a makeshift instrument if given the appropriate code. A perfect example is buck50 developed by [Mark Rubin], an open source firmware to turn a STM32 “Blue Pill” into a multi-purpose test and measurement instrument.

buck50 comes with a plethora of functionality built in which includes an oscilloscope, logic analyzer, and bus monitor. The device is a two way street and also comes with GPIO control as well as PWM output. There’s really a remarkable amount of functionality crammed into the project. [Mark] provides a Python application that exposes a text based UI for configuring and using the device though commands and lots of commands which makes this really nerdy. There are a number of options to visualize the data captured which includes gnuplot, gtk wave and PulseView to name a few.

[Mark] does a fantastic job not only with the firmware but also with the documentation, and we really think this makes the project stand out. Commands are well documented and everything is available on [GitHub] for your hacking pleasure. And if you are about to order a Blue Pill online, you might want to check out the nitty-gritty of the clones that are floating around.

Thanks [JohnU] for the tip!

Actuator Opens The Door To Drier Dishes

Dishwashers are great at washing dishes and even rinsing them, most of the time. Where they tend to fail is in the drying part. Somehow these things dry hot enough to warp stoneware dishes, but not so well that things are actually dry when you open the door. Blame it on the lack of air movement.

Ideally, the dishwasher cycle is started soon after dinner time so it can be finished and opened up before it’s time for bed. But if you do that, then you miss all the dishes from late-night snacking and the occasional wine glass. Wait until bedtime to start it, and it has to sit several hours with moisture inside. Obviously, the answer is to listen for the victory beeps at the end of the cycle, and use a slow but forceful actuator to push the door open.

[Ivan Stepaniuk] is listening for the dishwasher’s frequencies with a microphone, amplifying them with a trusty LM386, and using an STM32 blue pill to crunch the audio. [Ivan] has plans to incorporate an ESP8266 board for IoT, presumably to get a notification when the door has been opened successfully. Check out the demo after the break.

Yes, dishwashers are great until they aren’t, and some little part breaks. But why pay for a new detergent compartment cover when you can just print one?

Continue reading “Actuator Opens The Door To Drier Dishes”

STM32 Gets Up Close And Personal With Mandelbrot

The Mandelbrot set is a curious mathematical oddity that, while interesting in its own right, is also a useful tool for benchmarking various types of computers. Its constant computing requirement when zooming in and out on the function, combined with the fact that it can be zoomed indefinitely, means that it takes some quality hardware and software to display it properly. [Thanassis] has made this a pet project of his, running Mandelbrot set visualizations in different ways on many different hardware platforms.

This particular one is based on an STM32 board called the Blue Pill, which [Thanassis] chose because he hadn’t yet done a continuous Mandelbrot zoom on a microcontroller yet. The display is handled by a tiny 16K IPS color screen, and some clever memory tricks had to come into play in order to get smooth video output since the STM has only 20 kB available. The integer multiplication is also tricky on a platform this small while keeping the continuous zoom function, so it’s limited to fixed point multiplication.

Even with the limitations of the platform, he is still able to achieve nearly double-digit FPS rates with this one. If you want to play around with graphics like this on an STM platform, [Thanassis] has released all of the source code on his GitHub page, but if you’d like to see more Mandelbrot manipulation you can check out one of his older projects where he built a similar project on an FPGA.

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STM32 Clones: The Good, The Bad And The Ugly

Whenever a product becomes popular, it’s only a matter of time before other companies start feeling the urge to hitch a ride on this popularity. This phenomenon is the primary reason why so many terrible toys and video games have been produced over the years. Yet it also drives the world of electronics. Hence it should come as no surprise that ST’s highly successful ARM-based series of microcontrollers (MCUs) has seen its share of imitations, clones and outright fakes.

The fakes are probably the most problematic, as those chips pretend to be genuine STM32 parts down to the markings on the IC package, while compatibility with the part they are pretending to be can differ wildly. For the imitations and clones that carry their own markings, things are a bit more fuzzy, as one could reasonably pretend that those companies just so happened to have designed MCUs that purely by coincidence happen to be fully pin- and register compatible with those highly popular competing MCU designs. That would be the sincerest form of flattery.

Let’s take a look at which fakes and imitations are around, and what it means if you end up with one. Continue reading “STM32 Clones: The Good, The Bad And The Ugly”

STM32 Blue Pill Turned GPG Security Token

Feeling the cost of commercial options like the YubiKey and Nitrokey were too high, [TheStaticTurtle] started researching DIY alternatives. He found an open source project allows the STM32F103 to act as a USB cryptographic token for GNU Privacy Guard, which was a start. All he had to do was build a suitable device to install it on.

Blue Pill proof of concept

The first step was to test the software out on the popular “Blue Pill” development board, which [TheStaticTurtle] documents in the write-up should anyone want to give it a try themselves. The ST-Link V2 was already a supported target, so it only took some relatively minor tweaks to get running and add support for a simple push button. The output of gpg --card-status showed the device was working as expected, so with the software sorted, it was time to take a closer look at the hardware.

To create his “TurtleAuth” dongle, [TheStaticTurtle] started with the basic layout of the Blue Pill and added in a TTP223E touch control IC. The original Micro USB port was also swapped for a male USB-A connector so the device could be plugged directly into a computer. An upper PCB, containing the status LEDs and touch pad, was then designed so it would fit over the main board as an enclosure of sorts. While the sides are still open, the device looks robust enough to handle life in a laptop bag at least.

While it’s not exactly a common project, this isn’t the first time we’ve seen somebody spin up their own hardware token. More evidence of what the dedicated individual can accomplish these days on a relatively limited budget.