Do7-beagle.sh

#!/bin/sh

CLOCK=162
LATCH=161
DATA=145
PIN_MUX=uart2_rts
PIN_MUX_VAL=4

gpio_init()
{
    [ -e /sys/kernel/debug/omap_mux ] || mount -t debugfs none /sys/kernel/debug
    echo ${PIN_MUX_VAL} > /sys/kernel/debug/omap_mux/${PIN_MUX}

    echo ${CLOCK} > /sys/class/gpio/export
    echo ${LATCH} > /sys/class/gpio/export
    echo ${DATA} > /sys/class/gpio/export

    echo low > /sys/class/gpio/gpio${CLOCK}/direction
    echo low > /sys/class/gpio/gpio${LATCH}/direction
    echo low > /sys/class/gpio/gpio${DATA}/direction
}

raw()
{
    local data="$1"
    local i
    for i in $(seq 0 7); do
        echo $(( (~$data >> (7 - $i)) & 1 )) > /sys/class/gpio/gpio${DATA}/value
        echo 1 > /sys/class/gpio/gpio${CLOCK}/value
        echo 0 > /sys/class/gpio/gpio${CLOCK}/value
    done

    echo 1 > /sys/class/gpio/gpio${LATCH}/value
    echo 0 > /sys/class/gpio/gpio${LATCH}/value
}

set_segs()
{
    local segs="$1"
    local data=0
    local i
    A=1
    B=2
    C=4
    D=8
    E=16
    F=32
    G=64
    P=128
    for i in $(seq 0 $(( ${#segs} - 1 )) ); do
        n=$(eval echo \$${segs:$i:1})
        data=$(( $data + $n ))
    done
    raw $data
}

lookup()
{
    local v=$(echo -n $1)
    [ -z "$v" ] && return
cat << "__EOF__" | grep -F -e "$v " | cut -f 2 -d ' '
0 ABCDEF
1 BC
2 ABGED
3 ABGCD
4 FBGC
5 AFGCD
6 AFGECD
7 FABC
8 ABCDEFG
9 ABCDFG
A ABCEFG
B CDEFG
C ADEF
D BCDEG
E ADEFG
F AEFG
G ACDEF
H BCEFG
I BC
J BCDE
K ACEFG
L DEF
M ACEG
N CEG
O CDEG
P ABEFG
Q ABCFG
R EG
S AFGCD
T DEFG
U BCDEF
V CDE
W BDFG
X ADG
Y BCDFG
Z BEG
- G
| BC
' B
` F
^ ABF
[ ADEF
] ABCD
= GD
_ D
/ BE
\ CF
+ EFG
! BP
? ABP
__EOF__
}

data="$1"

if [ -z "$data" ]; then
    echo No data byte
    return 1
fi

gpio_init

if [ "${data:0:2}" == "0x" ]; then
    raw $data
elif [ "${data:0:1}" == "/" ]; then
    for i in "$@"; do
        set_segs ${i:1}
        usleep 250000
    done
else
    data=$(echo "$data" | tr [a-z] [A-Z])
    while [ -n "${data}" ]; do
        if [ "${data:0:1}" = "." ]; then
            set_segs P
        elif [ "${data:1:1}" = "." ]; then
            set_segs "$(lookup ${data:0:1})P"
            data="${data:1}"
        else
            set_segs $(lookup ${data:0:1})
        fi
        data="${data:1}"
        [ -n "${data}" ] && usleep 250000
    done
fi