This is a serial ISP flashing tool for WCH RISC-V microcontrollers that runs in a web browser. Entirely self-contained, with no additional software, libraries, or drivers required.

It uses the JavaScript Web Serial browser API, and so requires support for this feature by the browser. At time of writing, only the following browsers feature support for the Web Serial API: Chrome version 89+, Edge version 89+, Opera version 76+. This tool does not work in FireFox and Safari, due to lack of support for the API.

• Connect using any available serial port (e.g. COM/TTY) interface.
• Write, verify, and erase user application flash.
• Read and write configuration option bytes.
• Loads firmware images in these formats:
  • Intel Hex
  • S-Record
  • ELF
  • Raw binary
• Load firmware from local file or external URL.
• Can take query string parameters to auto-select device and/or auto-load firmware from URL.
• Hex preview listing of loaded firmware image.
• Optional DTR/RTS sequence for auto-reset into bootloader.

Currently supported RISC-V WCH microcontrollers:

• CH32V00x
• CH32L103
• CH32V103
• CH32V20x
• CH32V30x
• CH32X03x

• This tool only works with the WCH factory bootloader. If you have overwritten a chip's bootloader code (the 'BOOT' flash area) with a custom bootloader, this tool will not be compatible.
• The WCH bootloader protocol does not support reading user application flash. There is no command within the bootloader to do so.
• Native USB communication is not supported.

Building requires the bundling tool esbuild, a copy of which needs be installed in a tools\esbuild sub-folder of the project. Please note building is currently only supported on Windows.

To build:

1. Open a command prompt in the project folder.
2. Run build.bat.
3. The resultant HTML, JS, and CSS files will be output to the dist sub-folder.

If any Linux/Mac users are feeling resourceful, they may wish to review the contents of build.bat and translate the script within to an appropriate shell script or discrete commands. 😄

If you downloaded a pre-built release, first extract the contents of the zip file to a location of your choice.

Open in your web browser the index.html file from the dist folder.

If you want to deploy a copy of this tool to be hosted on your own web server, simply upload all files within the dist folder to a location of your choice on your web server.

This work is licenced under the GNU Affero General Public License v3.0. See LICENSE.txt for details.