#!/bin/bash

cape="BB-BONE-BACONE"
clk=/sys/class/gpio/gpio2
serial=/sys/class/gpio/gpio4
latch=/sys/class/gpio/gpio5
button=/sys/class/gpio/gpio22
red=/sys/class/pwm/pwm0
green=/sys/class/pwm/pwm1
blue=/sys/class/pwm/pwm2
pot=/sys/devices/ocp*/bacon_adc_helper*/AIN5
pot_min=0
pot_max=1800000

function setup {
    local i

    # load cape if not loaded yet
    grep 2>&1 >/dev/null "$cape" /sys/devices/bone_capemgr*/slots
    if [ $? -ne 0 ] ; then
        echo "$cape" >/sys/devices/bone_capemgr*/slots
        sleep 5
        # check if loaded
        grep 2>&1 >/dev/null "$cape" /sys/devices/bone_capemgr*/slots
        if [ $? -ne 0 ] ; then
            echo "Failed to load $cape"
            exit 5
        fi
    fi
    # export the 3 pwms (it will fail if already exported but we don't care)
    for i in `seq 0 2` ; do
        echo $i 2>/dev/null >/sys/class/pwm/export
    done
}

function set_clk {
    echo $1 > "$clk/value"
}

function set_serial {
    echo $1 > "$serial/value"
}

function set_latch {
    echo $1 > "$latch/value"
}

function get_button {
    local v

    v=`cat "$button/value"`
    return $v
}

function get_button_press {
    # wait for down
    while true ; do
        get_button
        if [ $? -eq 0 ] ; then
            break
        fi
        sleep 0.2
    done
    # wait for up
    while true ; do
        get_button
        if [ $? -eq 1 ] ; then
            break
        fi
        sleep 0.2
    done
}

function get_pot {
    local v

    # read twice
    v=`cat $pot`
    v=`cat $pot`
    export POT_VALUE="$v"
    return 0
}

function set_pwm {

    local pwm
    local prev

    pwm="$1"

    # stop pwm

    prev=`cat $pwm/run`
    if [ x$prev == x1 ] ; then
        echo 0 > "$pwm/run"
    fi
    if [ x$3 != "x" ] ; then
        echo "$3" > "$pwm/duty_ns"
    fi
    if [ x$4 != "x" ] ; then
        echo "$4" > "$pwm/period_ns"
    fi
    echo $2 > "$pwm/run"
}

function set_8seg {
    local t
    local i
    local v

    set_latch 0

    v=($*)
    for i in `seq 0 7` ; do
        # t = !v[7-i]
        t=$((!${v[$((7 - $i))]}))
        set_clk 0
        set_serial $t
        set_clk 1
    done

    set_latch 1
}

function set_digit {

    local dot
    local d

    if [ x$1 == x ] ; then
        echo "set_digit: missing arguments"
        exit 5
    fi

    dot=`echo $1 | sed 's/^[0-9]//'`
    if [ x$dot == "x." ] ; then
        d=1
    else
        d=0
    fi

    case $1 in
        0*)  set_8seg 1 1 1 1 1 1 0 $d ;;
        1*)  set_8seg 0 1 1 0 0 0 0 $d ;;
        2*)  set_8seg 1 1 0 1 1 0 1 $d ;;
        3*)  set_8seg 1 1 1 1 0 0 1 $d ;;
        4*)  set_8seg 0 1 1 0 0 1 1 $d ;;
        5*)  set_8seg 1 0 1 1 0 1 1 $d ;;
        6*)  set_8seg 1 0 1 1 1 1 1 $d ;;
        7*)  set_8seg 1 1 1 0 0 0 0 $d ;;
        8*)  set_8seg 1 1 1 1 1 1 1 $d ;;
        9*)  set_8seg 1 1 1 1 0 1 1 $d ;;
        off) set_8seg 0 0 0 0 0 0 0 0  ;;
        on)  set_8seg 1 1 1 1 1 1 1 1  ;;
    esac
}

# setup everything
setup

# 7 segment display test

set_pwm $red 0
sleep 0.5
set_pwm $green 0
sleep 0.5
set_pwm $blue 0
sleep 0.5

echo "Red PWM"
set_pwm $red 1 10000 20000
sleep 1
set_pwm $red 0
sleep 1

echo "Green PWM"
set_pwm $green 1 10000 20000
sleep 1
set_pwm $green 0
sleep 1

echo "Blue PWM"
set_pwm $blue 1 10000 20000
sleep 1
set_pwm $blue 0
sleep 1

echo "7 segment display all off"
set_digit off
sleep 1

echo "7 segment display all on"
set_digit on
sleep 1

echo "7 segment display digit check"
for i in `seq 0 9` ; do
    set_digit $i
    sleep 0.5
done

echo "7 segment display digit check (with a dot)"
for i in `seq 0 9` ; do
    set_digit "$i."
      sleep 0.5
done

echo "Press button to continue"
get_button_press
echo "button pressed"

echo "Slider test (press button to exit)"

while true ; do
    get_button
    if [ $? -eq 0 ] ; then
        break
    fi
    get_pot
    v=$POT_VALUE
    d=$(( ($v * 10) / $pot_max))
    set_digit $d

    r=$(( ($v * 20000) / $pot_max))

    set_pwm $red 1 $r 20000
    set_pwm $green 1 $r 20000
    set_pwm $blue 1 $r 20000
done

set_pwm $red 0
set_pwm $green 0
set_pwm $blue 0

set_digit off