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:
www.raspberryp...
new uart port cable: www.digikey.co...
Copy the c_send5.cpp and arduino program for Xiao SAMD21: github.com/sol...
Xiao SAMD21: www.seeedstudi...
FTDI cable: www.amazon.com...
pi pinout: www.raspberryp...
USB OTG adapter: www.amazon.com...

[@jchidley]

Thanks for the helpful information about the new port. I am glad that you pointed out the ttyAMA10 for the new debug port - I had seen the documentation that said it was ttyAMA0 (which is the current port).

[@jazmineayabar]

beautiful job

[@clifffiftytwo]

New subscriber. Thank you / overturning a bit of bad info STILL on the internet. The cable Ladyada referenced is out-of-stock but her video teaches you to check for “alternate lengths”!
I’ve found a local hobby shop to be a source of small JST connectors as these are used in RC model Lipo charging. Don’t know if they’ll have 3-pin 1mm but will check soon.

[@MojaveRider223]

Dumb question: theoretically it is possible to connect something like a GPS on ttyAMA10 while something else is connected on ttyAMA0?

[@masha_kasha5061]

Can you run rs232 or rs485 over the port ?

[@samwechsler]

You will need a level shifter for those to go from 3.3V TTL to something like +/- 12V en.wikipedia.org/wiki/RS-232

[@maxpalast9155]

For rs232 you can look out for boards with the max3232 chip

[@user-iz3rt6fd1x]

how to rfid interface with Pi5

[@xrafter]

I have been trying to get a console in the gpio uart but couldn't. Here is why:
According to documentation I need to add dtparam=uart0_console=on to enable it. This make /dev/serial0 points to /dev/ttyAMA0 which is I believe what the rpi4 does.