redbutton driver

#!/bin/bash
LID_CLOSED=21
BUTTON_PRESSED=22
LID_OPEN=23

while true
do
    echo -ne "\x08\x00\x00\x00\x00\x00\x00\x02" > buf
    dd if=buf of=/dev/hidraw3 bs=8 count=1 conv=notrunc
    rm -f buf
    dd if=/dev/hidraw3 of=buf bs=1 count=1
    last=$LID_CLOSED
    siz=$(cat buf | wc -c)
    [ $siz -eq 1 ] || continue
    status=$(head -c1 buf)
    estado=$(echo $status | od -h | grep -Eo "0a[0-9]{2}" | cut -f2 -da)
    echo $estado
    status=$((16#$estado))
    echo last: $last
    echo status: $status
    [ $last -eq $LID_CLOSED -a $status -eq $LID_OPEN ] && echo LID OPEN $last $status
    [ $last -ne $BUTTON_PRESSED -a $status -eq $BUTTON_PRESSED ] && echo FIRE $last $status
    [ $last -ne $LID_CLOSED -a $status -eq $LID_CLOSED ] && echo LID CLOSED $last $status
    last=$status
done