IOT_Project: 人體監測系統

由人體紅外線感測器感測人體方向，再由step motor帶著相機轉至偵測方向並進行拍攝，並可於網頁上看到目前鏡頭畫面。

Input：人體紅外線感測器。
Output：鏡頭畫面顯示於網頁、拍攝照片存於本機。
Video Demo: https://drive.google.com/open?id=1eMStMv6OOEz_Fmdua6y77xWdLzWBTzqE

所需材料：
樹莓派 * 1
麵包板 * 1
鏡頭 * 1
人體紅外線感測器 * 6
步進馬達 * 1
杜邦線 約80條
筷子一雙
雙面膠 * 1
泡綿膠 * 1

步驟一：安裝Node.js

參考教學：https://www.w3schools.com/nodejs/nodejs_raspberrypi.asp
Update your system package list:
pi@w3demopi:~ $ sudo apt-get update
Upgrade all your installed packages to their latest version:
pi@w3demopi:~ $ sudo apt-get dist-upgrade
Doing this regularly will keep your Raspberry Pi installation up to date.
To download and install newest version of Node.js, use the following command:
pi@w3demopi:~ $ curl -sL https://deb.nodesource.com/setup_8.x | sudo -E bash -
Now install it by running:
pi@w3demopi:~ $ sudo apt-get install -y nodejs
Check that the installation was successful, and the version number of Node.js with:
pi@w3demopi:~ $ node -v

步驟二：建立於網頁上監控鏡頭畫面的Server端檔案

參考教學：http://thejackalofjavascript.com/rpi-live-streaming/
在Terminal中run
mkdir node_programs
To step inside that folder, run
cd node_programs
For this post, we will create a new folder named liveStreaming and will step inside this folder. Run
mkdir liveStreaming && cd liveStreaming
First we will initialize a new node project here. Run
npm init
Fill it up as applicable.
Now, we will install express and socket.io modules on our pi. Run
npm install express socket.io --save
Once they are installed, create a new file named index.js.
於index.js中拷入index.js的程式碼
Now we will create a new folder named stream at the root of the liveStreaming folder. This is where our image will be saved.

步驟三：建立於網頁上監控鏡頭畫面的Client端檔案

參考教學：http://thejackalofjavascript.com/rpi-live-streaming/
在livestreaming資料夾中建立index.html檔
於index.html中拷入index.html的程式碼
程式碼完成後，即可執行
node index.js
執行後，於瀏覽器網址列輸入自己的IP位址＋:3000即可看到鏡頭的畫面
http://Your_IP_Address:3000

步驟四：接電路與鏡頭

樹莓派GPIO參考：https://pinout.xyz/
步進馬達使用、連接參考：https://www.youtube.com/watch?v=LUbhPKBL_IU&t=182s
人體感測器連接參考：http://iot.pcsalt.com/detecting-obstacle-with-ir-infrared-sensor-raspberry-pi-3/
鏡頭連接參考：https://projects.raspberrypi.org/en/projects/getting-started-with-picamera
我們一共會使用樹莓派的10個Pin（BCM制）：
人體感應器使用PIN 5, 6, 13, 19, 26, 21
馬達使用PIN 4, 17, 27, 22
接法請參考上述連結

步驟五：撰寫人體感測與鏡頭旋轉程式

IR.py檔案即為我們主要邏輯控制的Python檔
首先載入我們所需的套件與設定GPIO的格式
from picamera import PiCamera
from gpiozero import LED
from signal import pause
import sys
import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)

再來，設定相機、人體感測器、和步進馬達的PIN
camera = PiCamera()
LED_PIN = 12
IR_PIN1 = 5
IR_PIN2 = 6
IR_PIN3 = 13
IR_PIN4 = 19
IR_PIN5 = 26
IR_PIN6 = 21

ControlPin = [4,17,27,22]

for pin in ControlPin:
GPIO.setup(pin, GPIO.OUT)
GPIO.output(pin,0)

indicator = LED(LED_PIN)
GPIO.setup(IR_PIN1, GPIO.IN)
GPIO.setup(IR_PIN2, GPIO.IN)
GPIO.setup(IR_PIN3, GPIO.IN)
GPIO.setup(IR_PIN4, GPIO.IN)
GPIO.setup(IR_PIN5, GPIO.IN)
GPIO.setup(IR_PIN6, GPIO.IN)

接著定義步進馬達的旋轉速度與方向
步進馬達的運作模式可參考：https://www.youtube.com/watch?v=LUbhPKBL_IU&t=182s
seq1為順時鐘旋轉、seq2為逆時鐘旋轉
seq1 = [ [1,0,0,0],
[1,1,0,0],
[0,1,0,0],
[0,1,1,0],
[0,0,1,0],
[0,0,1,1],
[0,0,0,1],
[1,0,0,1]]

seq2 = [ [1,0,0,0],
[1,0,0,1],
[0,0,0,1],
[0,0,1,1],
[0,0,1,0],
[0,1,1,0],
[0,1,0,0],
[1,1,0,0]]

接著定義使步進馬達旋轉的函數
用count作為觀測目前程式跑了多久的指標，以及用current_position紀錄目前步進馬達的位置
count = 1
current_position = 1

rotate旋轉函數主要判斷
(1) 偵測到的位置在目前位置的相對方向
(2) 偵測到的位置距離目前位置多少個半圈（128）
來決定要用順時鐘旋轉還是逆時針旋轉，以及旋轉多少角度
最後在旋轉完後開啟相機進行拍攝
def rotate(current, detect):
print(current)
print(detect)
if current == detect:
range_num = 0
seq = seq1
elif current > detect:
seq = seq1
if current - detect == 1:
range_num = 128
elif current - detect == 2:
range_num = 256
elif current - detect == 3:
range_num = 384
elif current - detect == 4:
range_num = 512
elif current - detect == 6:
range_num = 640
elif current < detect:
seq = seq2
if detect - current == 1:
range_num = 128
elif detect - current == 2:
range_num = 256
elif detect - current == 3:
range_num = 384
elif detect - current == 4:
range_num = 512
elif detect - current == 5:
range_num = 640
for i in range(range_num):
for halfstep in range(8):
for pin in range(4):
GPIO.output(ControlPin[pin], seq[halfstep][pin])
time.sleep(0.001)
camera.start_preview()
camera.capture('/home/pi/Desktop/image.jpg')
camera.stop_preview()

最後，開一個無限迴圈進行人體監測，若監測到後輸入監測到的感測器方位執行rotate函數，步進馬達即會旋轉到該方位
while True:
detect_1 = GPIO.input(IR_PIN1)
detect_2 = GPIO.input(IR_PIN2)
detect_3 = GPIO.input(IR_PIN3)
detect_4 = GPIO.input(IR_PIN4)
detect_5 = GPIO.input(IR_PIN5)
detect_6 = GPIO.input(IR_PIN6)
if detect_1 == False:
print("{:>3} Sensor1 Detected!".format(count))
time.sleep(0.5)
rotate(current_position, 1)
current_position = 1
elif detect_2 == False:
print("{:>3} Sensor2 Detected!".format(count))
rotate(current_position, 2)
time.sleep(0.5)
current_position = 2
elif detect_3 == False:
print("{:>3} Sensor3 Detected!".format(count))
time.sleep(0.5)
rotate(current_position, 3)
current_position = 3
elif detect_4 == False:
print("{:>3} Sensor4 Detected!".format(count))
time.sleep(0.5)
rotate(current_position, 4)
current_position = 4
elif detect_5 == False:
print("{:>3} Sensor5 Detected!".format(count))
time.sleep(0.5)
rotate(current_position, 5)
current_position = 5
elif detect_6 == False:
print("{:>3} Sensor6 Detected!".format(count))
time.sleep(0.5)
rotate(current_position, 6)
current_position = 6
else:
indicator.off()
print("{:>3} Nothing detected".format(count))
count += 1
time.sleep(0.2)
GPIO.cleanup()

步驟六：固定相機及執行IR.py程式

利用1/4的竹筷利用雙面膠＋泡綿膠固定於步進馬達的轉軸上
再將相機固定於竹筷上即可使相機隨著步進馬達轉動 最後，再將步進馬達同樣使用雙面膠＋泡綿膠固定於樹莓派的塑膠殼上即可完成本次人體監控系統的專案！