- \n
- Uploading via USB-to-TTL adapter<\/a><\/li>\n
- Uploading via SWD (Serial Wire Debug)<\/a><\/li>\n
- Easiest: Uploading via HID bootloader and USB <\/a><\/li>\n
- Uploading via Maple-DFU-Bootloader<\/a><\/li>\n<\/ul>\n<\/li>\n
- BlackPill variants<\/a><\/li>\n
- Uploading sketches to the BlackPill board<\/a>\n
- \n
- Easiest: Uploading via DFU and USB<\/a><\/li>\n
- Uploading via serial or SWD<\/a><\/li>\n
- Not Arduino-compatible: WeAct HID bootloader<\/a><\/li>\n<\/ul>\n<\/li>\n
- Uploading sketches to Nucleo boards<\/a><\/li>\n
- Upload sketches to the Arduino GIGA R1 WiFi board<\/a><\/li>\n
- Appendix 1 – Checking the real flash size<\/a><\/li>\n<\/ul>\n\n
What I will not go into: STM32CubeIDE \/ STM32CubeMX<\/h4>\n\n
STM32CubeMX<\/a> is a graphical configuration tool for STM32 microcontrollers that can be used to set pins, peripherals and clock systems. It automatically generates initialization code based on the STM32Cube HAL library. STM32CubeIDE<\/a> is a free development environment from ST based on Eclipse. It integrates editor, compiler, debugger and STM32CubeMX in a single tool. This allows STM32 projects to be fully implemented from configuration to debugging. <\/p>\n
I won ‘t<\/strong> go into these tools in this article. Maybe I’ll do a separate post on this at some point. <\/p>\n\n
STM32 boards – Overview<\/h2>\n\n
“STM” stands for the semiconductor electronics manufacturer STMicroelectronics<\/a> (abbreviation: “ST”). Among other things, ST develops and produces 8- and 32-bit microcontrollers, which are used on hundreds of different boards. I will only discuss a selection of 32-bit variants here. <\/p>\n
STM32 microcontrollers are based on the ARM architecture. The ARM architecture was developed by ARM Ltd. Microcontroller manufacturers such as ST use the architecture as licensees. <\/p>\n
ST itself uses its microcontrollers on the Nucleo development boards<\/a>, discovery kits<\/a> and evaluation boards<\/a>. Arduino also has a number of boards based on STM32 MCUs, such as the Portenta series or the Arduino GIGA R1 WiFi board. There are also many other electronics suppliers who have their own STM32 boards in their range, such as Adafruit with its Adafruit STM32F405 Feather Express<\/a>. <\/p>\n\n
The blue or the black pill?<\/h5>\n\n
And then there is the large group of BluePill and BlackPill boards. They are extremely inexpensive but not clearly defined, as their designations are not protected brand names but nicknames assigned by the STM32 community. <\/p>\n
Under the names “BluePill” and “BlackPill”, you can buy boards in different versions and with different microcontrollers. One major problem is the large number of counterfeit STM32 microcontrollers. On the one hand, these are not always clearly recognizable as counterfeits, and on the other hand, they sometimes have properties that differ from the original. In addition, there are also incorrectly assembled boards. <\/p>\n\n
A few examples of STM32 boards<\/h4>\n\n
\n\n![\"STM32](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/06\/nucleo_L412KB.jpg\")
<\/a>Nucleo-L412KB<\/figcaption><\/figure>\n<\/div><\/div>\n\n\n\n \n![\"STM32](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/06\/nucleo_F446RE.jpg\")
<\/a>Nucleo-F446RE<\/figcaption><\/figure>\n<\/div><\/div>\n\n\n\n \n![\"STM32](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/06\/bluepill.jpg\")
<\/a>BluePill<\/figcaption><\/figure>\n<\/div><\/div>\n<\/div>\n\n \n\n![\"STM32](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/06\/arduino_giga.jpg\")
<\/a>Arduino GIGA R1 WiFi<\/figcaption><\/figure>\n<\/div><\/div>\n\n\n\n \n![\"STM32-Boards](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/06\/stmf103cx_demo.jpg\")
<\/a>STM32F103Cx Demo Board<\/figcaption><\/figure>\n<\/div><\/div>\n\n\n\n \n![\"STM32](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/06\/blackpill_F401.jpg\")
<\/a>BlackPill<\/figcaption><\/figure>\n<\/div><\/div>\n<\/div>\n\n The following table lists selected features of some STM32 boards. This is merely intended to give a certain impression of the league we are playing in here. <\/p>\n\n
![\"Selected](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/06\/overview_stm32_boards-1024x496.png\")
<\/a>Selected features of some STM32 boards<\/figcaption><\/figure>\n\n Nomenclature of STM32 microcontrollers<\/h2>\n\n
There are certain rules for the designation of STM32 microcontrollers, but unfortunately the nomenclature is not consistent across the entire portfolio. This means that certain codes can have a different meaning in different series. However, the designation of the microcontrollers follows a certain pattern; here, as an example, the STM32F103C8T6: <\/p>\n\n
![\"Name](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/06\/STM32_Nomenclature-2-1024x148.png\")
<\/a><\/figure>\n\nThe first capital letter indicates the Type<\/strong>:<\/p>\n
- \n
- F<\/strong> = Mainstream \/ Foundation<\/li>\n
- G<\/strong> = General Purpose<\/li>\n
- H<\/strong> = High Performance<\/li>\n
- L \/ U<\/strong> = Low Power \/ Ultra Low Power<\/li>\n
- W<\/strong> = Wireless<\/li>\n<\/ul>\n
The following number codes the ARM Cortex used:<\/p>\n\n
![\"Name](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/06\/stm32_nomenclature_core-1.png\")
<\/a>Core coding<\/figcaption><\/figure>\n\n This is followed by the productline<\/strong>. For example, F103<\/em> stands for the Performance Line, F100<\/em> is the Value Line. These numbers do not directly encode technical properties. <\/p>\n\n
The number of pins (No of Pins<\/strong>) is usually defined as follows: <\/p>\n\n
![\"Name](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/06\/stm32_nomenclature_pins.png\")
<\/a>Coding of the number of pins<\/figcaption><\/figure>\n\n Here is the size of the flash (Flash Size<\/strong>):<\/p>\n\n
![\"Name](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/06\/stm32_nomenclature_flash.png\")
<\/a>Flash size coding<\/figcaption><\/figure>\n\n You will come across the following codes for the package<\/strong>:<\/p>\n\n
![\"Name](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/06\/stm32_nomenclature_package.png\")
<\/a>Coding of the package<\/figcaption><\/figure>\n\n And the following applies to the operating temperature limits (T-range<\/strong>):<\/p>\n
- \n
- 6: -40 to +85 \u00b0C<\/li>\n
- 8: -40 to +105 \u00b0C<\/li>\n<\/ul>\n
However, as mentioned above, the designations are not always consistent. Take a look at the data sheet or the product descriptions before you order anything! <\/p>\n\n
Preparations<\/h2>\n\n
Installing board package<\/h3>\n\n
The board package I am using is Arduino_Core_STM32<\/a> from stm32duino. I chose it because it supports some unofficial boards as well as many Nucleo boards. For the current release, you must use the Arduino IDE 2.x or go back to an older version of the board package (< 2.8.0)<\/strong>. <\/p>\n
To install, first enter the following board administrator URL under File \u2192 Settings \u2192 “Additional boards manager URLs”:<\/p>\n
https:\/\/github.com\/stm32duino\/BoardManagerFiles\/raw\/main\/package_stmicroelectronics_index.json<\/p>\n\n
Then go to the boards manager and enter STM32 as the search term. You will find the package under the name STM32 MCU based Boards<\/strong>. Click on “Install”. <\/p>\n
Is this installation description too short for you? Then you will find detailed instructions with pictures here<\/a>. <\/p>\n\n
Alternative board package: STM32F1XX\/GD32F1XX<\/h4>\n\n
With STM32F1XX\/GD32F1XX there is another, quite common board package, which is now outdated. You can find it here<\/a> on GitHub under the name Arduino_STM32. As the name STM32F1<\/strong>XX\/GD32F1XX suggests, the package only supports some of the STM32 boards, but some additional boards with microcontrollers from Giga Device. It is also characterized by lean code and broad community support. <\/p>\n\n
Optional: Installing STMCubeProgrammer<\/h3>\n\n
You can download STMCubeProgrammer here<\/a> for free. Among other things, it allows you: <\/p>\n
- \n
- Flashing a bootloader.<\/li>\n
- Getting information about your STM32 chip.<\/li>\n
- Reading the flash and writing to it.<\/li>\n
- Setting up write protection.<\/li>\n
- Making certain settings, e.g. for the watchdog.<\/li>\n
- Reading registers.<\/li>\n<\/ul>\n
You can also use your STM32 boards without this program. However, I recommend it, especially if you do a lot with the BluePill. <\/p>\n\n
![\"STM32CubeProgrammer](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/07\/STM32CubeProgrammer-1024x545.png\")
<\/a>STM32CubeProgrammer<\/figcaption><\/figure>\n\n BluePill board variants<\/h2>\n\n
STMF103C8T6- and STM32F103CB-based BluePill boards<\/h4>\n\n
In most cases, your BluePill boards will be the version with the STMF103C8T6, which should originally have a flash of 64 kB. There is also a version with 128 kB RAM (F103CBT6). However, many F103C8T6 chips actually have 128 kB flash. You can find out how much flash your board has in the appendix. F103C8T6 chips with 128 kB can<\/em> be fake, but they don’t have to<\/em> be, as ST sometimes uses higher-quality chips for logistical reasons. <\/p>\n
There are also variants with microcontrollers from Giga Device<\/a>, such as the GD32F103xx family.<\/p>\n\n
STM32F103C6T6-based BluePill boards<\/h4>\n\n
With 32 kB flash, 10 kB RAM and fewer interfaces, the STM32F103C6T6 is the little brother of the STM32F103C8T6. Apart from the different microcontroller, the boards assembled with the “C6T6” usually have the same design. <\/p>\n
What didn’t work for me with these boards was uploading sketches via HID bootloader over USB (more on this below). Otherwise, they did what they were supposed to do. However, I did not test these boards intensively. <\/p>\n
In two out of four orders from different stores, I received the big brother instead of the STM32F103C6T6 variant without comment. <\/p>\n\n
BluePill boards with counterfeit chips<\/h4>\n\n
As already mentioned, BluePill boards with counterfeit chips, especially with alleged STM32F103C8T6 microcontrollers, are widespread. Most counterfeits work in principle, but there are deviations in the details. For example, there are reports of excessive power consumption, as some fake chips ignore low power functions. Others report general instability. The HID bootloader also does not work with many fake chips. Further indications of fakes are <\/p>\n
- \n
- Chip labeling that is only printed on and not lasered in. The laser engraving should be visible. <\/li>\n
- Obviously wrong ST logo.<\/li>\n<\/ul>\n
I received a BluePill version, which according to the (printed) label is equipped with an STMF103C8T6, but even has a flash of 256 kB. <\/p>\n\n
BluePill boards with wrong parts<\/h4>\n\n
Then there are BluePill boards with a false pull-up resistor for the D+ line of the USB connection. You will find the resistor on the back of the board, labeled as R10. This resistor should have a size of 1.5 k\u03a9 (label: 152); instead, you can probably also find R10 resistors with 10 k\u03a9 (label: 103). However, none have come between my fingers. A hardware solution for the associated problems can be found here<\/a>; a software solution can be found here<\/a>. <\/p>\n\n
Uploading sketches to the BluePill board<\/h2>\n\n
Although the BluePill board has a USB port, it cannot be programmed via USB without further precautions. I will show you several methods for uploading programs. <\/p>\n\n
Uploading via USB-to-TTL adapter<\/h3>\n\n
Connection<\/h4>\n\n
For this method, you need a USB-to-TTL or FTDI adapter. It is best to use a model that can be switched to 3.3 volts. Connect the adapter to the BluePill board as follows: <\/p>\n\n
![\"BluePill](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/07\/bluepill_ftdi-1024x350.png\")
<\/a>Programming BluePill with USB-to-TTL adapter<\/figcaption><\/figure>\n\n A9 is TXD1, A10 is RXD1. <\/p>\n
As most of the pins on the BluePill boards are 5V-tolerant (as input!), you could also work with five volts here. But since this does not apply to all pins and also not to pins in ADC mode, I would advise you to generally work with 3.3 volts so that you don’t forget it at some point. <\/p>\n\n
Settings in the Arduino IDE<\/h4>\n\n
In the Arduino IDE, choose your board under “Tools”: “STM32 MCU based boards” \u2192 “Generic STM32F1 series”. Then set the correct version under “Board part number”: <\/p>\n\n
![\"BluePill](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/07\/bluepill_versions_in_ide.png\")
<\/a>BluePill selection in Arduino IDE <\/figcaption><\/figure>\n\n Select the port to which your USB-to-TTL adapter is connected and set the following as the “Upload Method”: <\/p>\n
- \n
- Upload method: STM32CubeProgrammer (Serial)<\/li>\n<\/ul>\n\n
If you want to use the serial monitor, there are two options: <\/p>\n
- \n
- U(S)ART support: Enabled (generic ‘Serial’). \n
- \n
- Serial monitor is connected via the USB-to-TTL adapter.<\/li>\n<\/ul>\n<\/li>\n
- USB support (if available): “CDC (generic ‘Serial’ supersede U(S)ART)”\n
- \n
- Serial monitor is connected via the USB port of the BluePill board.<\/li>\n
- The USB connection appears as a separate port. <\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n
If you set 1 and<\/em> 2 as specified above, setting 2 will “override” setting 1.<\/p>\n\n
Otherwise, leave the settings unchanged:<\/p>\n\n
![\"BluePill](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/07\/settings.png\")
<\/a>Settings in the Arduino IDE<\/figcaption><\/figure>\n\n Settings on the board<\/h4>\n\n
To upload sketches to the BluePill board via serial, you must set it to programming mode. To do this, set the BOOT0 jumper to 1 and leave the BOOT1 jumper at 0. Then press the reset button. <\/p>\n
More precisely, the above setting leads to the “System Memory Boot Mode”. This means that the boot process starts in the system memory. The STM32F1x microcontroller has a hardware bootloader there. <\/p>\n
In the BOOT0 = 0 position, the STM32F1x is in “Main Flash Memory Boot Mode”. This means that the boot process starts in the flash memory where your uploaded program is saved to. <\/p>\n\n
\n<\/div>\n\n\n\n\n![\"BluePill](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/06\/blue_pill_boot_settings-1-1024x427.jpg\")
<\/a>Boot Mode – left: System Memory, right: Main Flash Memory <\/figcaption><\/figure>\n<\/div>\n\n\n\n <\/div>\n<\/div>\n\nUploading an example sketch<\/h4>\n\n
Once you have made all the settings, upload your first sketch using the “upload arrow”. You could use the following example to test the serial monitor: <\/p>\n\n
void setup() {\n Serial.begin(115200);\n pinMode(LED_BUILTIN, OUTPUT);\n}\n\nvoid loop() {\n digitalWrite(LED_BUILTIN, HIGH);\n delay(1000); \n digitalWrite(LED_BUILTIN, LOW); \n delay(1000); \n Serial.println(\"Hello World\");\n}\n<\/pre>\n\nThe sketch starts immediately after uploading. A new reset leads back to programming mode. To prevent this, set the BOOT0 jumper back to 0. <\/p>\n\n
Uploading via SWD (Serial Wire Debug)<\/h3>\n\n
Serial Wire Debug is an ARM-specific communication interface based on JTAG (Joint Test Action Group). In contrast to JTAG, SWD requires only one data line (SWDIO) and one clock line (SW(D)CLK). <\/p>\n
To be able to use SWD, you need an ST-LINK or a J-Link programmer (from SEGGER Microcontroller<\/a>), whereby the J-Link programmer is more of a professional device. There are also various SWD programmers that are advertised as “ST_LINK compatible”. <\/p>\n\n
Uploading with ST-LINK\/V2 Mini<\/h4>\n\n
The ST-LINK\/V2 Mini is probably the most cost-effective SWD programmer with a price of < 10 euros. The “Mini” is usually omitted. <\/p>\n\n
![\"ST_LINK\/V2](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/07\/stlink_v2_mini-1024x257.jpg\")
<\/a>ST_LINK\/V2 Mini<\/figcaption><\/figure>\n\n The programmer has a USB-A connector under the protective cap on one side and a 10-pin socket on the other. You connect the ST-LINK\/V2 to your BluePill board as follows: <\/p>\n\n
![\"BluePill](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/06\/blue_pill_stlink_v2-1024x282.png\")
Programming BluePill with ST-Link\/V2<\/figcaption><\/figure>\n\n Make sure that you do not connect the 3.3V pin of the BluePill board to the 5.0V pin of the programmer. <\/p>\n
You can leave the BOOTx jumpers on the BluePill board in the zero position when programming via SWD. In the Arduino IDE, select the upload method: <\/p>\n
- \n
- Upload method: “STM32CubeProgrammer (SWD)”<\/li>\n<\/ul>\n
You cannot establish a connection to the serial monitor via the SWD pins (with the ST-LINK\/V2). Instead, you can use the USB port for this purpose. To do this, select in the settings: <\/p>\n
- \n
- USB support (if available): CDC (generic ‘Serial’ supersede U(S)ART) <\/li>\n<\/ul>\n
Alternatively, you could also use a USB-to-TTL adapter, but then without the USB support. <\/p>\n\n
The “big” ST-LINK\/V2<\/h4>\n
\n![\"ST-LINK\/V2\"](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/07\/stlink_v2_big-1-179x300.jpg\")
<\/a><\/figure>\n<\/div>\nThe “actual” ST-LINK\/V2 is larger. It is connected to the computer via a USB micro-connector. The 4-pin socket in the middle is an interface for STM8 microcontrollers. The 20-pin socket allows connection to STM32 microcontrollers via SWD or JTAG. <\/p>\n
If you have boards with a 20-pin socket or you want to program via JTAG, then choosing this programmer makes sense. For most people, the “mini” version will be sufficient. <\/p>\n
Finally, there is the ST-LINK\/V2-ISOL version, which provides electrical isolation from the microcontroller. <\/p>\n
Only 2 of the pins plus the power supply are required for the SWD connection. You have to be a little careful not to miscount and use the wrong pins. <\/p>\n\n
![\"\"](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/07\/st_link_v2_white_swd_pins-1024x237.png\")
<\/a>SWD pins of the 20-pin socket of the ST-LINK\/V2<\/figcaption><\/figure>\n\n Easiest: Uploading via HID bootloader and USB<\/h3>\n\n
The fiddling with the jumpers when flashing via serial can be annoying. Connecting an STM32 board to an ST-LINK\/V2 (Mini) is also inconvenient (although you should always know how well off you are if you count that<\/em> as one of your problems \ud83d\ude09 ). <\/p>\n
It would be more convenient if you could upload your sketches just via USB. This is actually possible by flashing a suitable bootloader. We use an HID bootloader, which is so called because it communicates according to the HID (Human Interface Device) protocol. The HID protocol was developed for USB devices such as keyboards and mice. The great thing about it is that you don’t need to install a driver. <\/p>\n
First, it should be said that this did not work for me with all BluePill boards<\/strong>, although the non-functioning ones were visually identical to the functioning boards, including the resistor values. I have not found out the reason yet. <\/p>\n\n
Variant 1: Flashing the HID bootloader via serial<\/h4>\n\n
There are already a number of instructions on how to upload the bootloader to the BluePill board. You can find a detailed YouTube video here<\/a> and instructions with many pictures here<\/a>. And here is my own quick guide: <\/p>\n\n
- \n
- Download the bootloader package stm32_binaries.zip from here<\/a> and unzip it.\n
- \n
- For the BluePill board, hid_generic_pc13.bin is the right choice. “pc13” stands for the pin that is connected to the board LED. You can find the bootloader under …\\stm32_binaries\\stm32_binaries\\F103\\low_and_medium_density. <\/li>\n<\/ul>\n<\/li>\n
- Connect the BluePill board to the PC via a USB-to-TTL adapter as shown above. <\/li>\n
- Set the Boot0 jumper to 1 and reset the board.<\/li>\n
- Open STMCubeProgrammer. On the right-hand side, select UART and set the port to which the USB-to-TTL adapter is connected. Then click on “Connect”. <\/li>\n<\/ol>\n\n
![\"STMCubeProgrammer](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/06\/stmcubeprogrammer.png\")
STMCubeProgrammer – Flashing the bootloader<\/figcaption><\/figure>\n\n - \n
- On the left-hand side of STMCubeProgrammer, go to “Erasing & Programming”. <\/li>\n
- Enter the path to hid_generic_pc13.bin in “File path”. “Start address” is 0x08000000. <\/li>\n
- Click on “Start Programming”. Confirm the success message with OK and click on “Disconnect”, but leave the board connected to the power supply. <\/li>\n
- Set the Boot0 jumper to 0 and reset the board. Now you can disconnect the USB-to-TTL adapter from the board. However, it will not interfere if you leave it connected. <\/li>\n
- Connect the board to the PC via USB. <\/li>\n
- In the Arduino IDE you set:\n
- \n
- Upload Method: “HID Bootloader 2.2”.<\/li>\n
- USB Support (if available): “CDC (generic ‘Serial’ supersede U(S)ART)”.<\/li>\n
- U(S)ART support: “Enabled (generic ‘Serial’)”. However, this is not actually relevant. \n
- \n
- You don’t see a port yet. That is OK. <\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n
- Upload a sketch. Now you can find the board under “Port” and can also use the serial monitor. <\/li>\n<\/ol>\n
Please let me know if any points are missing or misunderstood in these instructions. <\/p>\n\n
Variant 2 – Flashing the HID bootloader via ST-LINK\/V2<\/h4>\n\n
If you want to flash the bootloader to the BluePill board via ST-LINK V2, there are only minor differences in the procedure:<\/p>\n\n
- \n
- Connect the ST-LINK\/V2 to the BluePill board and the PC.<\/li>\n
- In STMCubeProgrammer, select ST-LINK instead of UART.<\/li>\n
- You can leave the jumpers on the BluePill in the zero position. <\/li>\n<\/ul>\n\n
Deleting the HID bootloader<\/h4>\n\n
If you flash sketches to your board via SWD or serial, the HID bootloader will be overwritten. This is the easiest way to get rid of the bootloader. Or you can delete the bootloader using the “Erase flash memory” function in STMCubeProgrammer. However, this only worked – at least for me – via the ST-LINK\/V2, but not via Serial. <\/p>\n\n
Uploading via Maple-DFU-Bootloader<\/h3>\n\n
I do not recommend this method because, unlike uploading via HID bootloader, you will need to install additional drivers. I am only introducing it here for the sake of completeness. By the way, DFU stands for D<\/strong>evice F<\/strong>irmware U<\/strong>pgrade. <\/p>\n
Here are the brief instructions:<\/p>\n
- \n
- Download the correct bootloader from STM32duino-bootloader<\/a>. In most cases this should be generic_boot20_pc13.bin. You can find it here in the binaries<\/a> directory. Double-click the file, go to the download icon, and save the file where you find it. <\/li>\n
- Upload the bootloader with STM32CubeProgrammer onto your BluePill board. You do this as described above for the HID bootloader. <\/li>\n
- Download the Arduino_STM32 package here<\/a>. To do this, click on the green “Code” button, then on “Download ZIP”. Unzip the package (somewhere). <\/li>\n
- Go to the drivers\/win directory and execute install_drivers.bat. This will install the Maple drivers. <\/li>\n
- Connect the board to the PC via USB. BOOT0 and BOOT1 shall be set to 0. <\/li>\n
- In the Arduino IDE, select the correct board:\n
- \n
- Select the correct port (not the one under “dfu Ports”, if something appears there).<\/li>\n
- Upload method: “Maple DFU Bootloader 2.0”.<\/li>\n
- USB support: “CDC (generic ‘Serial’ supersede U(S)ART)”.<\/li>\n<\/ul>\n<\/li>\n
- Upload your sketch. You will probably get an error message at the end that the port you have set is not available. Change it. You can then upload new sketches without any further settings. <\/li>\n<\/ul>\n\n
As already mentioned, I see no advantage of the Maple DFU bootloader over the HID bootloader. I was able to program the BluePill boards that could not be programmed with the HID bootloader exactly once using the Maple DFU bootloader. On the next upload, the Arduino IDE did not find the port. So no improvement here either. <\/p>\n\n
BlackPill variants<\/h2>\n\n
The name “BlackPill” is just as unprotected as “BluePill”. When people talk about “BlackPill”, they usually mean the design by WeAct Studio (WeAct for short). There is very little information about WeAct itself on the internet. Links to the company are classified as unsafe by Edge and Firefox. WeAct’s GitHub page<\/a> and the WeAct Studio Shop<\/a> on AliExpress give an impression of what WeAct does. <\/p>\n
The \u201cWeAct-BlackPill\u201d is based on the STM32F401CCU6 or the STM32F411CEU6. In addition to its black design, its three buttons \u201cNRST,\u201d \u201cBOOT0,\u201d and \u201cKEY\u201d are particularly striking. <\/p>\n\n
![\"BlackPill](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/07\/blackpill_F401-1024x275.jpg\")
<\/a>BlackPill with STM32F401CCU6 MCU<\/figcaption><\/figure>\n\n But, as previously mentioned, the name “BlackPill” is not protected, which is why you will come across many other variants. For example, there is an STM32F103C8T6-based model here<\/a>. The model shown below, based on the STM32F401RCT6, is somewhat bizarre. Due to the unfortunate spacing of the pin headers, it does not fit on breadboards: <\/p>\n\n
\n<\/div>\n\n\n\n\n![\"STM32F401RCT6-based](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/06\/STM32F401RCT6-1.jpg\")
<\/a>STM32F401RCT6 BlackPill, fixed on one side <\/figcaption><\/figure>\n<\/div>\n\n\n\n <\/div>\n<\/div>\n\nOtherwise the board worked (board part number: “Generic F401RCTx”).<\/p>\n\n
Uploading sketches to the BlackPill board<\/h2>\n\n
Uploading via DFU and USB<\/h3>\n\n
You can program the BlackPill conveniently via USB, as you do not need to flash an additional bootloader. First, set the correct board in the Arduino IDE: STM32 MCU based boards \u2192 Generic STM32F4 series. Then select the correct variant, e.g. BlackPill 411CE. <\/p>\n
Select “STMCubeProgrammer (DFU)” as the upload method. If you want to access the serial monitor via USB, select “CDC (generic ‘Serial’ supersede U(S)ART)” as USB support. <\/p>\n\n
- Download the correct bootloader from STM32duino-bootloader<\/a>. In most cases this should be generic_boot20_pc13.bin. You can find it here in the binaries<\/a> directory. Double-click the file, go to the download icon, and save the file where you find it. <\/li>\n
- Download the bootloader package stm32_binaries.zip from here<\/a> and unzip it.\n
- USB support (if available): CDC (generic ‘Serial’ supersede U(S)ART) <\/li>\n<\/ul>\n
- Upload method: “STM32CubeProgrammer (SWD)”<\/li>\n<\/ul>\n
- U(S)ART support: Enabled (generic ‘Serial’). \n
- Upload method: STM32CubeProgrammer (Serial)<\/li>\n<\/ul>\n\n
- G<\/strong> = General Purpose<\/li>\n
- Uploading via serial or SWD<\/a><\/li>\n
- Uploading via SWD (Serial Wire Debug)<\/a><\/li>\n
![](\"https:\/\/wolles-elektronikkiste.de\/wp-content\/uploads\/2025\/07\/settings_blackpill.png\"){kind=link}