Geehy Embedded Bootloader

Dev-1997

Hi,
I would like to know whether Geehy provides any tutorial or documentation explaining how to program a Geehy MCU using another Geehy MCU through an embedded bootloader. If not, could you help me to understand how to do it?

The goal is to develop a stand-alone programmer for use in a mass production line for different Geehy MCUs.

Thank you in advance for your support.

Yang Chao

Dev-1997

Regarding your request, please note that we do not publicly disclose the communication protocol details of the chip’s internal Bootloader at this time.

However, you can download the GeehyProg software from the Geehy official website to achieve your goals.

This tool supports ISP functions, and for specific chips with USB capabilities, it also supports DFU functions.

For ISP: You need to connect via a USB-to-TTL adapter to the chip’s UART pins (PA9: UART_TX, PA10: UART_RX). We recommend keeping the baud rate between 1200 and 115200.

For DFU: A hardware connection compliant with the USB 2.0 standard is required.

How to enter Bootloader mode:
To bootstrap the chip into the ISP/DFU Bootloader, please set the BOOT0 pin to High and keep the BOOT1 pin at Low at the moment of chip reset.
In this mode, user code will not be actively executed, allowing you to use GeehyProg on a Windows PC to write and read code.

Please find the GeehyProg user manual attached.

geehyprog-user-manual.pdf

2MB

You can download the software via the link below:
https://global.geehy.com/design/hardware_detail/43

Dev-1997

Hi,

Thank you for the information.

Could you please confirm whether it is possible to program Geehy MCUs by using the Geehy-Link on-board circuit from a Tiny Board?

To clarify, the idea is to use the Geehy-Link on-board section available on the Tiny Board as a standalone programmer. In other words, we would like to isolate the Geehy-Link circuitry and use it to program other Geehy MCUs on a production line, similar to a dedicated test jig fixture.

Could you please confirm whether this approach is technically feasible and officially supported by Geehy Prog for mass production purposes?

Thank you in advance for your support.

Yang Chao

Hi, yes, you are correct.

Geehy TINY development boards equipped with the Geehy-Link circuitry feature a convenient snap-off design.

This allows you to separate a compact, independent Geehy-Link module from the main board.

This module is perfectly suited for providing CMSIS-DAP emulation and programming for other 3.3V MCUs via the SWD interface.

For software integration, you may refer to the emulation and programming guides for tools such as OpenOCD and PyOCD.

xpack-openocd-0120-6-win32-x64.zip

3MB

You can download the required “.cfg” configuration files from our official community, or access the “.pack” files directly from the chip’s SDK.

Furthermore, you are welcome to develop your own standalone programmer based on this circuit design.

If you need to program 5V MCUs, we recommend adding level isolation/shifters to ensure voltage compatibility.

yury.kapoyko

Yang Chao
Dear Yang Chao, you say, that own programmer may be developed based on this circuit design. I can see Geehy Link schematic section in TINY boards, but is there a firmware for it, either binary or sources?

Yang Chao

yury.kapoyko
Hi, please refer to the schematic below to verify our board-level integrated programmer design.

geehy-link-winusb-integrated-5v-3v3.pdf

638kB

This design incorporates the APM32F103CBT6 and features ISO6741FDWR isolation to ensure stable CMSIS-DAP debugging, USB device connectivity, and USB Virtual COM Port capabilities.

Regarding the firmware, you can download the tool to upgrade the Geehy-Link to WinUSB firmware here:
https://www.geehy.com/uploads/tool/GEEHY-LINK%20Upgraded%20%20Guide%20V1.0.zip

geehy-link-upgraded-guide-v10.zip

9MB

Important Note:
If you are using an older version of Keil MDK, you may need to use the USB-HID based driver instead. Please note that using the HID driver will disable the Virtual COM Port functionality. You can download the HID driver here:

geehy-link-hid-v10.bin

45kB

Yang Chao

yury.kapoyko
If you encounter any issues while using pyOCD, please refer to our latest guide: https://community.geehy.com/d/1008-a-guide-to-pyocd-and-openocd-hexbin-flashing-with-geehy-link