gpioshutdown

#!/bin/bash
# automatically shutdown RPi
# author: yoyojacky
# Date: 2016-12-27

# Define pin number's function.
# NOTE: here are using BCM naming system.
#+-----+-----+---------+------+---+---Pi 3---+---+------+---------+-----+-----+
# | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
# +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
# |     |     |    3.3v |      |   |  1 || 2  |   |      | 5v      |     |     |
# |   2 |   8 |   SDA.1 | ALT0 | 1 |  3 || 4  |   |      | 5v      |     |     |
# |   3 |   9 |   SCL.1 | ALT0 | 1 |  5 || 6  |   |      | 0v      |     |     |
# |   4 |   7 | GPIO. 7 |   IN | 1 |  7 || 8  | 0 | IN   | TxD     | 15  | 14  |
# |     |     |      0v |      |   |  9 || 10 | 1 | IN   | RxD     | 16  | 15  |
# |  17 |   0 | GPIO. 0 |   IN | 0 | 11 || 12 | 0 | IN   | GPIO. 1 | 1   | 18  |
# |  27 |   2 | GPIO. 2 |   IN | 0 | 13 || 14 |   |      | 0v      |     |     |
# |  22 |   3 | GPIO. 3 |   IN | 1 | 15 || 16 | 0 | IN   | GPIO. 4 | 4   | 23  |
# |     |     |    3.3v |      |   | 17 || 18 | 0 | IN   | GPIO. 5 | 5   | 24  |
# |  10 |  12 |    MOSI | ALT0 | 0 | 19 || 20 |   |      | 0v      |     |     |
# |   9 |  13 |    MISO | ALT0 | 0 | 21 || 22 | 0 | IN   | GPIO. 6 | 6   | 25  |
# |  11 |  14 |    SCLK | ALT0 | 0 | 23 || 24 | 1 | OUT  | CE0     | 10  | 8   |
# |     |     |      0v |      |   | 25 || 26 | 1 | OUT  | CE1     | 11  | 7   |
# |   0 |  30 |   SDA.0 |   IN | 1 | 27 || 28 | 1 | IN   | SCL.0   | 31  | 1   |
# |   5 |  21 | GPIO.21 |   IN | 1 | 29 || 30 |   |      | 0v      |     |     |
# |   6 |  22 | GPIO.22 |   IN | 1 | 31 || 32 | 0 | IN   | GPIO.26 | 26  | 12  |
# |  13 |  23 | GPIO.23 |   IN | 0 | 33 || 34 |   |      | 0v      |     |     |
# |  19 |  24 | GPIO.24 |   IN | 0 | 35 || 36 | 0 | IN   | GPIO.27 | 27  | 16  |
# |  26 |  25 | GPIO.25 |  OUT | 1 | 37 || 38 | 0 | IN   | GPIO.28 | 28  | 20  |
# |     |     |      0v |      |   | 39 || 40 | 0 | OUT  | GPIO.29 | 29  | 21  |
# +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
# | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
# +-----+-----+---------+------+---+---Pi 3---+---+------+---------+-----+-----+
## for example, BCM 26 pin is connected to the board.
shutdownPin=26

#This ListenPin is connected to BCM Pin 24. if BCM pin 24 is waiting for the signal from MCU.
#But shell script are running by gpio read Pin, so must be mapped to wringPi naming system.
# ListenPin=5 means wiringPi's gpio5 = BCM pin24.
ListenPin=5

#initialize the gpio pin.
function shutdownPinSetup(){
        `sh -c "sudo gpio mode 25 out"`
	`sh -c "sudo gpio write 25 1"`
         
}

#clear the settings.
function clear_ShutdownPin_setting(){
         `sh -c "sudo gpio mode 25 input"`
         `sh -c "sudo gpio write 25 0"`
}

#initializing shutdown pin for MCU.
shutdownPinSetup

#Main loop to detect ListenPin's level, if high level will shut down the system.
while true
do
   Signal_STATS=`gpio read ${ListenPin}`
   if [[ ${Signal_STATS} == 1 ]];then 
      sudo sync
      clear_ShutdownPin_setting
      sudo shutdown -h now
   fi
done