Serial bridge is an open-source printed circuit board by qzed, from the qzed/usb-serial-bridge repository on GitHub, published under the MIT licence. It is a 2-layer board of 80 × 25 mm with 48 parts on 55 nets, routed with 267 tracks and 45 vias.
It is built around the FT232RL. Its parts include 10 resistors, 8 capacitors, 6 diodes and 2 connectors. It belongs with the interfaces and adapters boards of this library.
Jumpers can be used to connect RX/TX and RTS/CTS lines at will.
Usage
Requirements:
A kernel supporting the FT232 USB to serial converter.
Ideally you will have USB and FT232 built into the kernel (=y) or the initramfs to enable early support at boot.
The USB-serial-USB bridge (or alternatively two similar USB-serial converters).
Usage:
Connect the jumper pins for the RX/TX (and optionally RTS/CTS) line pairs (i.e. TX1 to RX2, RX1 to TX2, and so on).
Connect the bridge to your host PC and your client to be debugged.
Open a terminal on your host PC, e.g. via minicom:
sh
minicom --device /dev/ttyUSBn --baudrate 115200
Make sure that you have selected the correct /dev/ttyUSBn device, where n stands for the device number of the serial bridge on the host.
Boot the kernel to be debugged on the client with the following command line options:
text
console=ttyUSBn,115200 console=tty0
Note that console=tty0 is optional.
This causes the main console to be allocated on the client itself, otherwise you will get no output on that device.
If you wish for the main console to be on the USB-serial device, you can switch those statements.
Again make sure to replace n with the correct device number (usually 0 assuming you have no other USB-serial device connected).
You can replace the baud rate (115200) with your desired one, however, make sure that it is set identically on both devices.
For further options see the respective kernel parameter documentation and the manpages for minicom.
It measures 80 × 25 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Serial bridge use?
48 parts, built around the FT232RL. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Serial bridge KiCad files?
From the qzed/usb-serial-bridge repository on GitHub, at the commit this page was made from: the board is serial-bridge.kicad_pcb and its schematic serial-bridge.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Serial bridge design in my own project?
Its repository publishes it under the MIT licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
SiliconToaster is an open-source hardware electromagnetic fault injection device, designed for hardware security research. It has the following features:
qzed/usb-serial-bridge1
