WCH RISC-V Microcontroller Web Serial ISP

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+, FireFox version 151+, Opera version 76+. This tool does not work in Safari, due to lack of support for the API.

[!NOTE] You can find a hosted version of this tool on my website, at: https://www.stasisleak.uk/wchisp/.

Features

• 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

Limitations

• 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

[!NOTE] A pre-built copy can be found in the Releases section of the GitHub repository.

Building requires the bundling tool esbuild, a copy of which will need to be installed in a tools sub-folder of the project - see below for details.

Windows

You must have a copy of the esbuild.exe binary executable in a tools\esbuild sub-folder.

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.

Linux

You must have a copy of the esbuild binary executable in a tools/esbuild/bin sub-folder.

1. Open a terminal and navigate to the project folder.
2. Run build.sh. You may need to first add 'execute' permissions to the script file (e.g. chmod a+x build.sh).
3. The resultant HTML, JS, and CSS files will be output to the dist sub-folder.

The Linux build script may also be useful on other Unix-like platforms - e.g. Mac, BSDs, etc. - but has not been tested with any of them.

Running

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.

Licence

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