Flash AM32 to Holybro Tekko32 45A Single-ESC
(Artery AT32F421) with ST-LINK V2

⚠️ This process is irreversible and the BLHeli32 firmware cannot be restored! ⚠️

The instructions on this page are for Artery AT32F421 MCUs. These MCUs use the uVision program instead of the STM32 Cube program to update the bootloader. Other ESCs, like the RDQ 3-6S 32bit dShot1200 30A ESC, also use the Artery AT32F421 MCU. However, these other ESCs may require the PB4 bootloader (instead of the default PA2), and they may require a different firmware build. Notes have been added to guide others through this process.


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Tekko 32 45A Single ESC Check if your ESC corresponds to the described model: Tekko32 45A Single-ESC, with Artery AT32F421(K8U7) MCU
Download ST-Link Utility: https://www.st.com/en/ development-tools/ stsw-link004.html
Install software & drivers (you will be ask if drivers should be installed during process)
Plug in your ST-Link device
Open ST-Link Utility Click ST-LINK ➡️ Firmware Update
Click Device Connect, then Yes>>>> to Upgrade Firmware (the upgrade is probably not necessary, but this way you can make sure that the ST Link works correctly) Unplug your ST Link
Download AT32F421_AM32_Bootloader: https://github.com/AlkaMotors/ AT32F421_AM32_Bootloader Unzip file
Download Keil MDK-Arm: https://www.keil.com/download/product/ Install software & drivers (you will be ask if drivers should be installed during process)
Go to the Bootloader folder and Unzip `ArteryTek.AT32F421…` (Just double click and you will be asked to install "Keil Pack Unzip" Confirm Unzip the Pack by clicking Next>> Close everything
Tekko 32 45A Single ESC Now it‘s time to connect to the ESC Connect the pads to the corresponding pins of the ST-Link as shown in the photo. You can solder thin wires to the pads or make the contact with pogo pins (which I prefer). The cables should all have the same length and should be twisted together ‼️ Be very careful on the `SWCLK` pad with this ESC! Here is extremely little space to the capacitors, to which V_Bat is applied ‼️
RDQ 3-6S 32bit dShot1200 30A ESC Skip this if updating the Tekko Connect the pads to the corresponding pins of the ST-Link as shown in the photo. You can solder thin wires to the pads or make the contact with pogo pins (which I prefer). The cables should all have the same length and should be twisted together ‼️ You must connect a Gnd wire! I made the ground connection using the negative battery pad for the ESC.:bangbang:
Tekko 32 45A Single ESC ℹ️ For me, the Pogo Pins P75-B1 work very well. Connect a battery plug to the `+` and `-` pad on the ESC.
Plug in your ST Link Power the ESC Go to the Bootloader folder and open the `AM32` Project file (µVision will open)
Right click Target 1, click Options for Target 1'…
Go to Debug-Tab (1) Select ST Link Debugger from dropdown (2) Click Settings (3)
If everything is connected correctly, you will see your target under SW Device. Confirm both windows with OK If you see no target connected, check your wiring between the ESC and the ST Link / check if the ESC is powered on
Right click Target 1, click Options for Target 1'… ➡️ Debug ➡️ Settings ➡️ Flash Download (1) Select the Programming Algorithm (2) Click Remove (3) Click Add (4)
Select the Flash Programming Algorithm `AT32F421 Flash user system data` (1) Click Add (2) Confirm both windows with OK
On the main screen select Flash ➡️ Download
Ignore the Error message and confirm with OK Right click Target 1, click Options for Target 1'… ➡️ Debug ➡️ Settings ➡️ Flash Download
Select the Programming Algorithm (1) Click Remove (2) Click Add (3)
Select the Flash Programming Algorithm `AT32F421 Int. Flash` (1) Click Add (2) Confirm both windows with OK ℹ️ Bootloader is set to `PA2` by default, so you don’t have to change something here
Skip this if updating the Tekko32. The RDQ 3-6S 32bit dShot1200 30A ESC requires the PB4 bootloader. To change from the `PA2` to the `PB4` bootloader, Double click on "main.c: (1) Edit the program ~lines 22/23. Uncomment the one you want; comment-out the other. (2) Open the Project Menu (3) Click "Build Target" (4).
On the main screen select Flash ➡️ Download Bootloader done! Close µVision window Unplug ESC Unplug ST Link and remove connection to the ESC (SWDIO, SWCLK, GND)
Download the ESC Config Tool: https://drive.google.com/file/d /1qw2f7nM6OZftIE5GTgMPWB5zXCELxYG9/view Unzip to a folder
Tekko 32 45A Single ESC Download and save the firmware (1) `AM32_WRAITH32_F421`: https://github.com/AlkaMotors/ AM32-MultiRotor-ESC-firmware/releases
RDQ 3-6S 32bit dShot1200 30A ESC Download and save the firmware (1) `AM32_TEKKO32_F421_1.93.hex`: https://github.com/AlkaMotors/ AM32-MultiRotor-ESC-firmware/releases Why these files with names of other ESCs? It is confusing... each ESC designer/manufacturer has their unique design. These designs vary by parts (like the MCU, FETs), but also by what pins are used on the MCU and for what purpose. The boot loader pin is one example of variation, but there are many other pins on the MCU that are used differently from one designer to the next. The AM32 firmware naming convention is still evolving... they know it is confusing. Currently, some less common ESCs are re-using compatible firmware files for hardware designs that match.
Connect your ESC to a Betaflight flightcontroller: Connect PWM pad of the ESC to a motor pad on the FC Connect GND pad from the ESC to GND next to the motor pads Connect the FC to your computer via USB
Do NOT power your ESC Start the ESC Config Tool: `SerialPortConnector`
Select the right COM Port and hit Connect Power your ESC
Goto Flash-Tab (1) and select the motor your ESC is attached to (2) Click Load Firmware (3) and select the downloaded firmware file Click Flash Firmware (4) All done! 🏁