Firmware for Raspberry Pi Pico that emulates USB-to-serial adapters. Linux uses its standard drivers. Data written to the serial port is echoed back.
| Profile | USB ID | Linux driver |
|---|---|---|
ft232r |
0403:6001 |
ftdi_sio |
pl2303-h |
067b:2303 |
pl2303 |
pl2303-hx |
067b:2303 |
pl2303 |
pl2303-ta |
067b:2303 |
pl2303 |
pl2303-tb |
067b:2303 |
pl2303 |
pl2303-hxd |
067b:2303 |
pl2303 |
pl2303-hxd-clone |
067b:2303 |
pl2303 |
pl2303-hxn |
067b:2303 |
pl2303 |
ch340 |
1a86:7523 |
ch341 |
cp2102 |
10c4:ea60 |
cp210x |
cdc-acm |
2e8a:000a |
cdc_acm |
cdc-test |
2e8a:000a |
cdc_acm |
siemens-sx1 |
11f5:0001 |
pl2303 |
siemens-x65 |
11f5:0003 |
pl2303 |
siemens-x75 |
11f5:0004 |
pl2303 |
siemens-ef81 |
11f5:0005 |
pl2303 |
benq-siemens-s81 |
04a5:4027 |
pl2303 |
Install CMake, the Arm GNU Toolchain, and picotool, then run:
git submodule update --init lib/pico-sdk lib/cherryusb
cmake -S . -B build -DPICO_BOARD=pico
cmake --build build
picotool load -v -x build/usb_serial_emu.uf2Without a saved profile, the firmware starts as ft232r.
The cdc-test profile provides a command protocol for serial-driver tests. See PROTOCOL.md.
Pass the current serial device and the new profile:
./tools/usbemu-switch.py /dev/ttyUSB1 select cp2102The device disconnects and appears again with a new USB ID. The selected profile is lost after a power cycle. Use --persist to save it:
./tools/usbemu-switch.py /dev/ttyUSB1 select cdc-acm --persist./tools/usbemu-switch.py /dev/ttyUSB1 bootsel
./tools/usbemu-switch.py /dev/ttyUSB1 flash build/usb_serial_emu.uf2The test switches through every loopback profile and checks the USB ID, Linux driver, control lines, BREAK, and loopback data:
./tools/verify-hardware.py /dev/ttyUSB1
./tools/verify-hardware.py /dev/ttyUSB1 --stress-seconds 10 --stress-rate 90000The firmware emulates the USB protocol and serial settings. It does not generate UART signals or reproduce hardware timing.
