BeagleBone/Serial Port

Serial ports 1, 2, 4 and 5 are present on the BeagleBone expansion connectors. The corresponding pins are multiplexed with other functions and the processor has to be configured in order to use them.

Ubuntu
The following configuration commands work on ARMhf Ubuntu. They have been entered by the  user. Other users would have to  these commands.

The CircuitCo BeagleBone RS232 cape has an EEPROM which automatically enables. The other ports have to be enabled separately. Using a breadboard (i.e. having no EEPROM) requires to also enable.

Install minicom: apt-get install minicom

Activate serial port ttyO1: echo 20 > /sys/kernel/debug/omap_mux/uart1_rxd echo 0 > /sys/kernel/debug/omap_mux/uart1_txd cat /sys/kernel/debug/omap_mux/uart1_rxd cat /sys/kernel/debug/omap_mux/uart1_txd minicom -o -b9600 -D/dev/ttyO1

Activate serial port ttyO2: echo 21 > /sys/kernel/debug/omap_mux/spi0_sclk echo 1 > /sys/kernel/debug/omap_mux/spi0_d0 cat /sys/kernel/debug/omap_mux/spi0_sclk cat /sys/kernel/debug/omap_mux/spi0_d0 minicom -o -b9600 -D/dev/ttyO2

Activate serial port ttyO4: echo 26 > /sys/kernel/debug/omap_mux/gpmc_wait0 echo 6 > /sys/kernel/debug/omap_mux/gpmc_wpn cat /sys/kernel/debug/omap_mux/gpmc_wait0 cat /sys/kernel/debug/omap_mux/gpmc_wpn minicom -o -b9600 -D/dev/ttyO4

Activate serial port ttyO5: echo 24 > /sys/kernel/debug/omap_mux/lcd_data9 echo 4 > /sys/kernel/debug/omap_mux/lcd_data8 cat /sys/kernel/debug/omap_mux/lcd_data9 cat /sys/kernel/debug/omap_mux/lcd_data8 minicom -o -b9600 -D/dev/ttyO5