UART1 on A+ model via camera port

[dstahlke]

Maybe not new, but a search didn't turn up much mention of this. It is possible to access a second serial port on the Model A+, and probably other boards of the same generation. Just solder some wires onto the camera connector. You can remove the plastic part of the connector with a spudger, and can remove the metal bits with a soldering iron (putting a big blob of solder on the tip helps).





Activate by adding these lines into /boot/config.txt:

dtoverlay=uart1,txd1_pin=32,rxd1_pin=41
force_turbo=1

The "force_turbo" line is needed because the UART1 clock is tied to core frequency. If the frequency changes due to load, so will the baud rate. force_turbo=1 keeps the chip at max frequency always. This might only be necessary if you've overclocked it.

Start a terminal like so (the number is the baud rate):
sudo /sbin/getty -L ttyS0 1000000