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RS-232 Port

1. Perform a loopback at RS-232 port by shorting pins 2 & 3 in DB9 connector J24 on the carrier board, or connect to another computer.

2. Enable UART1 when on-SOM Bluetooth is not mounted. Type the following commands in the Linux shell to enable:

$ echo 20 > /sys/class/gpio/export
$ echo out > /sys/class/gpio/gpio20/direction
$ echo 0 > /sys/class/gpio/gpio20/value

1. Start minicom.

$ minicom -D/dev/ttyO1 -b115200 -8

1. Type a few characters at the minicom and see that the loopback is working.