We say about the GPIO on the raspberryPi

1. Raspberry Pi 研習營
CAVE Education
徐豐智
E-mail:jesusvictory777@cavedu,com
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2. Session 6: GPIO
http://elinux.org/RPi_Low-
level_peripherals
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3. Introduction
• R-Pi offers lower-level interfaces intended to
connect more directly with chips and subsystem
modules
• Signals on the 2x13 header pins include SPI,
I2C, serial UART, 3V3 and 5V power
• Not "plug and play" and require care to avoid
miswiring
• The pins use a 3.3V logic level and are not
tolerant of 5V levels, such as you might find on a
5V powered Arduino
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4. GPIO
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5. • Not yet software-enabled are the
flex cable connectors with CSI
(camera serial interface) and DSI
(display serial interface), and a
serial link inside the HDMI
connector called CEC
• They provide 8 GPIO pins plus
access to I²C, SPI, UART), as well
as +3.3 V, +5 V and GND supply
lines
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6. RPi Serial Connection
• The following parameters are needed to connect to the Pi console, and
apply on both Linux and Windows.
– Speed (baud rate): 115200
– Bits: 8
– Parity: None
– Stop Bits: 1
– Flow Control: None
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http://elinux.org/RPi_Serial_Connection

7. Connection to a microcontroller
or other peripheral
• The TxD and RxD signals can also be connected directly
to similar signals on a microcontroller board like the
Arduino provided the signals are all at 3V3 levels.
• It's still a good idea to put 2K2 series resistors in the
lines to prevent damage when two outputs are
connected together, which could also happen if a GPIO
input pin is accidentally programmed as output.
• If your microcontroller uses 5V logic levels, level
conversion is usually necessary - see 'Connecting to a
PC' for details.
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8. 控制GPIO腳位
http://makezine.com/projects/tutori
al-raspberry-pi-gpio-pins-and-
python/
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9. 安裝GPIO for python函式庫
• 安裝python函式庫
• $sudo apt-get install RPi.GPIO
• Python的.py檔匯入函式庫
• import RPi.GPIO as GPIO
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10. GPIO example:LED blink
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• 接上LED，注意GPIO針腳是否接對

11. GPIO example:LED blink
• 新增.py檔，gpio_led.py
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12. GPIO example:LED blink
• 設定初始狀態，GPIO針腳
• import RPi.GPIO as GPIO #匯入函式庫
• import time #匯入函式庫
• GPIO.setwarnings(False) #關閉偵錯模式
• GPIO.setmode(GPIO.BCM) #設定腳位代號
• GPIO.setup(17,GPIO.OUT) #17號為輸出腳
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13. GPIO example:LED blink
• LED燈閃爍設定
• while True: #無限迴圈
• GPIO.output(17,True) #17腳輸出電壓(3.3V)
• time.sleep(2) #停頓2秒
• GPIO.output(17,False) #17腳不輸出電壓(0V)
• time.sleep(2)
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14. GPIO example:Button
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• 接上Button，注意GPIO針腳是否接對

15. GPIO example:Button
• 更改gpio_led.py
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16. GPIO example:Button
• 設定初始狀態，GPIO針腳
• import RPi.GPIO as GPIO ＃匯入函式庫
• import time ＃匯入函式庫
• GPIO.setwarnings(False) ＃關閉偵錯模式
• GPIO.setmode(GPIO.BCM) ＃設定腳位代號
• GPIO.setup(18,GPIO.IN) ＃18號為輸入腳
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17. GPIO example:Button
• 偵測Button是否被按下
• while True:
• input_value=GPIO.input(18) ＃讀取18號輸入腳，並存
入變數中
• if input_value ==False: ＃如果讀取為０Ｖ
• print( "The button has been pressed" )
• while input_value == False: ＃讀取為0V時，進入迴圈
• input_value = GPIO.input(18)
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18. GPIO example:Led_Button
• Button+LED
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19. GPIO example:Led_Button
• 新增.py檔，gpio_button.py
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20. GPIO example:Led_Button
• 設定初始狀態，GPIO針腳
• import RPi.GPIO as GPIO ＃匯入函式庫
• import time ＃匯入函式庫
• GPIO.setwarnings(False) ＃關閉偵錯模式
• GPIO.setmode(GPIO.BCM) ＃設定腳位代號
• GPIO.setup(18,GPIO.IN) ＃18號為輸入腳
• GPIO.setup(17,GPIO.OUT) #17號為輸出腳
• GPIO.output(17,False) #17號為0V(燈不亮)
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21. GPIO example:Led_Button
• 設定初始狀態，GPIO針腳
• while True:
• input_value=GPIO.input(18) #儲存18號輸入腳(按鈕)於變數
• if input_value ==False: #如果按鈕被按下
• print( "The button has been pressed,Lighting LED." )
• GPIO.output(17,True) #17號輸出腳給電(LED燈亮)
• while input_value == False: #按鈕被按下時進入迴圈
• input_value = GPIO.input(18) #讀取按鈕的狀態，存於變數中
• print( "The button has been pressed,Extiguishing LED." )
• if input_value == True : #如果按鈕沒被按下
• GPIO.output(17,False) # 17號輸出腳為零(LED燈暗)
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22. GPIO控制直流馬達
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23. (1)使用PWM控制直流馬達
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24. (1)pwm.py
• 新增檔案
• pwm.py
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25. (1)pwm.py
• GPIO.setup(18,GPIO.OUT)
• #設定通道
• p = GPIO.PWM(18,100)
• #設定頻率
• p.start(b)
• #設定Dutycycle
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26. (2)直流馬達+驅動IC
• 接上馬達驅動IC，L293D。
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27. (2)直流馬達+驅動IC
• 注意樹莓派宣告的位置
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28. (2)直流馬達+驅動IC
• 接上馬達驅動IC，L293D。
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29. (2)直流馬達+驅動IC
• 連接Rpi電源
• 與馬達外接電源
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30. (2)直流馬達+驅動IC
• 連接直流馬達
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31. (2)直流馬達+驅動IC
• 新增檔案L293D.py
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32. (2)直流馬達+驅動IC
• 第二組馬達連接IC
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33. (2)直流馬達+驅動IC
• 連接第二組馬達
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34. (3)pwm+驅動IC
• 新增檔案pwm2.py
• 可從pwm.py改
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35. Raspberry Pi - Installing a
RS232 Serial Port
http://www.savagehomeautomatio
n.com/projects/raspberry-pi-
installing-a-rs232-serial-port.html
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36. Raspberry Pi - RS232 Serial
Interface Options (Revisit)
SOFTWARE USE OF THE
SERIAL PORT
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37. make of backup of the two files
that we intend to modify
• sudo cp /boot/cmdline.txt
/boot/cmdline.bak
• sudo cp /etc/inittab /etc/inittab.bak
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38. Next
• we need to remove the "console=ttyAMA0,115200" and
"kgdboc=ttyAMA0,115200" configuration parameters from the
"/boot/cmdline.txt" configuration file.
• To edit the file use this command:
$ sudo nano /boot/cmdline.txt
• The file probably contains this default configuration line:
– dwc_otg.lpm_enable=0 console=ttyAMA0,115200 kgdboc=ttyAMA0,115200
console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait
• After removing the two configuration parameters, it will look similar
to this:
– dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4
elevator=deadline rootwait
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39. Last
• edit the "/etc/inittab" file and comment out
the use of the "ttyAMA0" serial port.
• To edit the file use this command:
$ sudo nano /etc/inittab
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40. Now towards the bottom of the file, look for a
configuration line that includes the "ttyAMA0" port
address
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41. Place a pound sign ("#") in front of the line to comment it
out. With a pound sign ("#") at the beginning of the line,
Linux will ignore this configuration line.
• Save the "/etc/inittab" file and then issue
this command to reboot the Raspberry Pi:
$ sudo reboot
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42. • Now you are ready to use the serial port
with a software application and the
operating system won't interfere with the
port.
• Use the device address "ttyAMA0" in your
application to access this serial port.
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43. Project:Create an internet
controlled robot using
Livebots
http://www.instructables.com/id/Cr
eate-an-internet-controlled-robot-
using-Livebots/step1/Have-Fun/
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44. Advanced GPIO for the
Raspberry Pi
https://pypi.python.org/pypi/RPIO
Extends RPi.GPIO with PWM,
GPIO interrups, TCP socket
interrupts, command line tools and
more
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45. RPIO is an advanced GPIO module
for the Raspberry Pi
• PWM via DMA (up to 1µs resolution)
• GPIO input and output (drop-in replacement
for RPi.GPIO)
• GPIO interrupts (callbacks when events occur on
input gpios)
• TCP socket interrupts (callbacks when tcp socket
clients send data)
• Command-line tools rpio and rpio-curses
• Well documented, fast source code with minimal
CPU usage
• Open source (LGPLv3+)
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46. RPIO的範例網站
http://pythonhosted.org/RPIO/
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47. 接線圖
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48. Installation
• $ sudo apt-get install python-setuptools
• $ sudo easy_install -U RPIO
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49. LXTerminal中，使用nano編輯程式
test.py
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50. 50

51. 下指令 $ sudo python test.py，接到
pin 11的LED以每0.1秒閃爍
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52. 思考RPIO.cleanup()指令
釋放GPIO的channel
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53. How to use GPIOs on
raspberry pi (Simple I/O, PWM
and UART)
https://sites.google.com/site/semill
eroadt/raspberry-pi-tutorials/gpio
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