Use the Raspberry Pi 5 Serial Ports

Use the Raspberry Pi 5 debug UART port (Serial0 -- ttyAMA10) or the traditional 40 pin GPIO UART port (ttyAMA0) to send serial data. Data is sent to a phone through FTDI cable and USB OTG adapter. Data is also sent to a Xiao SAMD21 chip in keyboard mode. This technique has also been demonstrated to work on Raspberry Pi 4, Orange Pi 5, and Teensy 3.6. The Raspberry Pi 5 is running the Bookworm 64 bit desktop operating system. All baud rates are 115200.

Correction: The diode used was 1N4004.

Raspberry Pi 5 documentation:
https://www.raspberrypi.com/documenta...

new uart port cable: https://www.digikey.com/en/products/d...

Copy the c_send5.cpp and arduino program for Xiao SAMD21: https://github.com/solarsamuel/send_s...

Xiao SAMD21: https://www.seeedstudio.com/Seeeduino...

FTDI cable: https://www.amazon.com/dp/B00HKJOVK4/...

pi pinout: https://www.raspberrypi.com/documenta...

USB OTG adapter: https://www.amazon.com/Thunderbolt-Co...