The “Black Pill” board with an STM32F4 Cortex-M4F MCU is already cheap, but I’ve just come across a clone going for just 49 cents plus shipping (34 cents to Thailand) based on a 240 MHz AT32 (or AT32F4) Cortex-M4F microcontroller with Arduino support. [Edit: the price looks like a lottery and everybody seems to get a different price, and not related to VAT. See comments section]
Other features are pretty much the same with two 20-pin headers for GPIOs, an SWD header, a USB Type-C port for power and programming, and a few buttons.
WeAct “Black Pill” board specifications:
- Microcontroller – Artery Technology AT32F403ACGU7 Cortex-M4F MCU @ 240MHz with 96 + 128KB RAM, 256KB zero wait-state flash, 768KB non-zero wait-state flash; note: RAM and flash size are somehow configurable by the user, and the numbers listed here are the maximum capacities.
- Storage – Footprint for SPI flash
- USB – 1x USB Type-C port for power and programming
- Debugging – 5x pin SWD header or USB port
- Expansion – 2x 20-pin headers with power signals, up to 7x U(S)ART, 3x I2C, 4x SPI, 1x USB FS, 10-channel 12-bit ADC, 4x I2S, 12x TIM, 2x CAN, 2-channel DAC
- Misc
- Reset (NRST), Boot0, and user buttons
- 8MHz/25MHz high-speed crystal oscillator
- 32.768KHz low-speed crystal oscillator
- Power – 5V via USB, 3.3V-5V power input via headers; 3.3V LDO maximum output current 100mA
- Dimensions – About 52.4 cm x 20.8 mm
The AT32 microcontroller can be programmed with the C language using the Keil IDE, and you’ll find resources such as SDK with code samples, a datasheet, a reference manual, and tools on GitHub. Alternatively, WeAct has also developed the ArduinoCore-AT32F4 “library” to allow users to easily program AT32F4 boards with the Arduino IDE, and you’ll find the code and instructions in a separate repository.
The Artery website also has a long list of Windows and Linux tools, application notes, and more details about their AT32F403A Series microcontrollers on the relevant product page.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
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Not all STM32 are equal. I have experience buying cheap blue pills and throwing them to trash, because they had crazy slow USB. So, this is very interesting, but still a gamble.
Another gamble is – how well their Arduino libraries support peripherals beyond the Blink? For example, will SPI work with DMA, or will you need to write a custom version of some other stm32 libraries to make them work together?
Of course they’re not all equal, that’s why they have multiple product lines! And why did you buy those Blue Pills in the first place, if you needed higher bandwidth? The STM32F103C8T6 that they use has a USB 2.0 full speed peripheral, ie. it’s 12Mbps max.
Besides that, this microcontroller in the article is an AT32, not an STM32. There are zero guarantees of any compatibility.
[ ‘1x USB FS’ ~12MB/s, USB-C only for power and programming (?),
that prices are (at least technically, mass production numbers?) stunning, without doubt (comparing STM32F4’s are starting ~$5, directly imported individually) ]
[ correction: ‘1x USB FS’ ~1.2MB/s ~12Mbps ]
Are they total clones or just similar in features?
There are lots of clones of the various STM32 MCUs, but they tend to have bugs in them, some peripherals may not work exactly the same and their IDs do not match the STM32-ones, so you can’t use the official STMicroelectronics tools with them. This is to say, compatibility is not guaranteed.
The price (for Thailand) is 2.82 US$ NOT 0.49 !!!!
This is what I get.
https://www.cnx-software.com/wp-content/uploads/2023/10/AT32-board-price.jpg
Now I can see it’s a “welcome deal”, so maybe if you have already purchased from WeAct on Aliexpress that price is not available??
I get €0.94 and the page loads in German, even though I’m not in Germany.
I shared the original dot com link. Aliexpress is a mess when it comes to languages. If you’ve previously visited Aliexpress in a specific language, they’ll consider that your preferred language :). So sometimes I visit links for Portugal, Indonesia, etc… and I have to manually change the language and currency. Sometimes it’s not sufficient, so I open a private window and edit the link to start with www aliexpress com.
I am open your link and AliExpress show me price 100 thb. I am have screenshot but no way to post it here.
As mentioned in the post update, the price is really confusing. I still get $0.49 or about 18 Baht as a logged-in user or as an anonymous user in a private window.
https://www.cnx-software.com/wp-content/uploads/2023/10/AT32-board-THB.jpg
Yes. To Europe it is €3.36 with €1.56 shipping. Using the link from the article.
I’ve just seen a discussion on Twitter about that. That price is when using the mobile app, but using a web browser it should be 49 cents or in that range (since VAT needed to be applied in Europe).
I’ve bought some of their boards before. The company seems legit, and the products seem to be of a consistent good quality. I never ended up making the project I intended with it – so I can’t say how seemless and “drop-in” the STM32 compatibility is. (I’ve also used their logic analyzer board successfully though..) But they sell other versions of the blue and black pills with actual STM32 chips as well as GD32 chips
This AT32 one on their taobao page is going for 22RMB (4USD)
And the STM32F4 based blackpill is 23RMB
I have bought from WeAct many times and have never had a defective board. Their PCB quality seems to be very good, above most PCBs from China.
I have used their boards in projects, including their STM32H743, STM32F411 blackpill, STM32G030 and STM32G431 and as far as I know they have all been genuine STM32 parts, they mention the specific microcontrollers used so they don’t seem to be passing off clones as genuine parts, they just say if it’s a clone.
I have used some of their ESP32 boards too, both the S3 and C3 boards and I haven’t had any issues with them either. I have used some of their non MCU boards, like their buck converters, over voltage protection and others and they have all worked well too.
So it is a company I have bought from multiple times and haven’t had any issues.
Wow, if you can find the few dollar energy harvester and supercapacitor to go with it, all your problems should be taken care of. (Few dollar water condensing or desalination being left as an example.) Just need to inline those Gaza Strip heavy equipment authority apps…
I’ve sold many hundreds of WeAct boards and they are always very high quality and well packaged.
$2.81 each + $2.97 shipping for me and I’ve bought a ton of things from AliExpress.
I guess that was a calling price, it is way up now they got some ads 🙂