The document provides information to help get started with the Raspberry Pi. It recommends downloading the operating system image from the Raspberry Pi website. It then discusses setting up the SD card with the image for both Windows and Mac users. The document proceeds to provide examples of code to blink an LED using the GPIO pins and read analog sensor values using the SPI interface. It demonstrates connecting additional hardware like displays and buttons. The examples show how to smooth sensor readings and control the display. The document emphasizes cleaning up resources to avoid issues.

1. Getting Started with
Raspberry Pi
Tom Paulus
www.tompaulus.com
@tompaulus

2. Recommended

3. Books

4. Hardware

5. Model B

6. Model A

7. Raspberry

8. Pi
Text
“Take

9. a

10. bite!”
CPU
Broadcom ARM11
SoC
Broadcom ARM11
SoC
Clock
Speed
Up to 1GHz
ClockSpeed*
Up to 1GHz
ClockSpeed*
Memory 256 MB 512 MB
USB 1 USB Port 2 USB Ports
Network None Onboard Ethernet
Model

11. BModel

12. A

14. Arduino

15. UNO

17. :

19. Arduino

20. MEGA

22. :

25. Raspberry

26. Pi

28. UNO MEGA DUE Pi Model A Pi Model B
Operating
Voltage
SRAM
FLASH-
Memory
Clock Speed
USB Host
Network
Audio /Video
Current I/O
pins
Digital I/O Pins
Analog Input
Pins
Price
5V 5V 3.3V 3.3V 3.3V
2 KB 8 KB 96 KB 265 MB 512 MB
32 KB 256 KB 512 KB up to 64 MB up to 64 MB
16 MHz 16 MHz 84 MHz 700 MHz* 700 MHz*
n/a n/a 1 1 2
n/a n/a n/a n/a
10/100 wired
Ethernet RJ45
n/a n/a n/a
HDMI, Composite
Video,
TRS-audio jack
HDMI, Composite
Video,
TRS-audio jack
40 mA 40 mA total 130 mA 2 to 16 mA 2 to 16 mA
14 (6 PWM) 54 (15 PWM) 54 (12 PWM) 17 (1 PWM) 17 (1 PWM)
6 16
12
2DAC Analog Out
0* 0*
$30 $59 $50 $25 $35

29. Initial Setup

30. http://www.raspberrypi.org/downloads

31. Recommended

32. SD

33. Cards
•Class

34. 4

35. Minimum
•2

36. GB

37. or

38. More
•Major

39. Brands

40. are

41. Better!

42. Creating Your Image
1. Download and Unzip the .img from www.raspberrypi.com
2. Format the SD Card to clear all Data
Windows Users:
Use
Win32DiskImager
Mac Users:
Use
Raspberry PI SD Installer OS X

44. Demo

45. GPIO

47. sudo apt-get install python-dev python-pip
sudo easy_install -U distribute
sudo pip install RPi.GPIO
Preparing

48. Python

49. Simple

50. Blink

51. App

52. from time import sleep
import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BCM)
#use the common numeration,
#also the one found on the Adafruit Cobbler
led = 21 # GPIO Port to which the LED is
connected
delay = .5
GPIO.setup(led, GPIO.OUT) # Set 'led' as and Output
print Press CTRL+C to exit
try:
while True:
GPIO.output(led, True) # led On
sleep(delay) # wait 'delay' seconds
GPIO.output(led, False) # led Off
sleep(delay) # wait another 'delay' seconds
except KeyboardInterrupt:
GPIO.output(led, False)
finally:
GPIO.cleanup()
blink.py

53. Hardware

54. Demo

55. Analogue

56. Input

57. MCP3008 8-Channel 10-Bit ADC With SPI Interface
Ra!berryPi
wi ADC

58. SPI requires four signals:
clock (SCLK)
master output/slave input (MOSI)
master input/slave output (MISO)
slave select (SS) or (CS) chip-select
Ra!berryPi
Se#al Pe#pheral Interface Bus - SPI

59. pi@raspberrypi ~ $ cat /etc/modprobe.d/raspi-blacklist.conf
# blacklist spi and i2c by default (many users don't need them)
blacklist spi-bcm2708
blacklist i2c-bcm2708
Loading Kernel Modules:
Edit the raspi-blacklist.conf, so that the spi module gets loaded,
Reboot, and confirm with lsmod that ‘spidev’ and ‘spi_bcm2708’ are now loaded and
ls /dev/spi* shows two spi devices: /dev/spidev0.0 and /dev/spidev0.1
Installing Dependencies:
sudo apt-get install python-dev git-core
Install Python bindings for Linux SPI access through spidev:
cd ~
git clone git://github.com/doceme/py-spidev
cd py-spidev/
sudo python setup.py install
... which creates /usr/local/lib/python2.7/dist-packages/spidev.so
SPI

60. I2C
SPI

61. IN =[0000 0001][1CNL ----][---- ----]
(8+channel) 4
OUT=[---- ----][---- -XXX][XXXX XXXX] (10bit)
((r[1] 3) 8) + r[2]

62. IN =[0000 0001][1CNL ----][---- ----]
(8+channel) 4
OUT=[---- ----][---- -XXX][XXXX XXXX]
r[0] ((r[1] 3) 8) + r[2]
r = spi.xfer2( [1, (8+chnnl)4, 0] )
return ((r[1] 3) 8) + r[2]

63. def analogRead(port, bus=0, ce=0):
Read the given ADC port and preform the necessary shifting of bits
spi.open(bus, ce) # CE port that the MCP3008 is connected to
if (port 7) or (port 0):
print 'analogRead -- Port Error, Must use a port between 0 and 7'
return -1
r = spi.xfer2([1, (8 + port) 4, 0])
value = ((r[1] 3) 8) + r[2]
spi.close()
return value

64. import time
import spidev
import RPi.GPIO as GPIO
# This program reads an analogue value form a potentiometer attached to port 0 on the MCP3008 Chip
spi = spidev.SpiDev()
pot_adc = 0
statusLED = 23 # GPIO port that our Status led is connected to
GPIO.setmode(GPIO.BCM)
GPIO.setup(statusLED, GPIO.OUT)
print Press CTRL+C to exit
try:
while True:
GPIO.output(statusLED, True) # Status Led On
print analogRead(pot_adc) # Print read value
time.sleep(.125) # Wait a little
GPIO.output(statusLED, False) # Status Led Off
time.sleep(.175) # Wait a bit longer
except KeyboardInterrupt:
GPIO.output(statusLED, False)
finally:
GPIO.cleanup()
ADC1.py

65. Hardware

66. But, That’s Just Ugly!

67. Let’s Add a Display