API

CH340 / serial mouse API

Python helper for relative mouse move and clicks for our RP2350/RP2040 CH340 firmware.

Overview

Communicate with our RP2350/RP2040 CH340 firmware. Supports CP210x and other similar USB-serial modules.

Install

Download ch340.py and example.py
pip install -r requirements.txt (or: pip install pyserial)
Flash / power your RP+CH340 and confirm Windows shows a COM port in Device Manager

Quick start

Pass a COM port, or leave it blank to auto-detect.

quickstart.pypython

from ch340 import ch340

dev = ch340('COM3')  # leave blank for auto

if not dev.open():
    raise SystemExit("Failed to open device")

dev.move(50, -20)
dev.click(ch340.BTN_L)
dev.close()

Methods

Method	Returns	Description
`ch340(port=None)`	`ch340`	Create a client. Port can be in the format of "COM3", "3", or None for auto-detect.
`findPort()`	`str \| None`	Static. Scans serial ports for CH340 / CH341 / CP210 adapters.
`open()`	`bool`	Open the serial port at 921600 baud. Returns False on failure.
`close()`	`bool`	Close the serial connection.
`isConnected()`	`bool`	True when the serial port is open.
`move(x, y)`	`None`	Relative mouse move.
`setButtons(mask)`	`None`	Set the held button mask (bitfield). Use RELEASE (0x00) to release.
`click(mask, down_ms=30)`	`None`	Press buttons for down_ms milliseconds, then release.

Button constants

Pass these masks to click() and setButtons().

buttons.pypython

ch340.RELEASE  # 0x00 — release all
ch340.BTN_L     # 0x01 — left
ch340.BTN_R     # 0x02 — right
ch340.BTN_M     # 0x04 — middle
ch340.BTN_X1    # 0x08 — side / back
ch340.BTN_X2    # 0x10 — side / forward

# Hold left, then release
dev.setButtons(ch340.BTN_L)
dev.setButtons(ch340.RELEASE)

Full example

example.pypython

from ch340 import ch340

dev = ch340('COM3') # leave blank for auto

if not dev.open():
    raise SystemExit("Failed to open device")

print(f'CH340 connected on port: {dev.port}')


# Relative mouse movement (x, y)
dev.move(50, -20)

# Button press
dev.click(ch340.BTN_L)              # left click for 30 ms (default)
dev.click(ch340.BTN_R, down_ms=50)  # right click for 50ms

# Hold a button down until you tell it to release
dev.setButtons(ch340.BTN_L) # hold left click
# do something
dev.setButtons(ch340.RELEASE) # release all


dev.close()