Install hardware driver libraries for Python
General
sudo apt-get install build-essential python-dev git python-pip python-rpi.gpio
RPI pinout guide
http://pinout.xyz
Note: for the guide it is assumed /home/pi/sources/ exists, you can also take another directory for downloaded source code
I2C
sudo apt-get install python-smbus i2c-tools
sudo raspi-config
advanced->I2C
enable I2C
sudo nano /etc/modules
add the lines
i2c-bcm2708
i2c-dev
Uncomment the I2C module
sudo nano /etc/modprobe.d/raspi-blacklist.conf
sudo reboot
sudo i2cdetect -l
sudo i2cdetect -y 0 #1 instead of 0 for newer RPI
PIR motion sensor
5V-12V Vcc, <1mA, 3.3V signal
when motion is detected signal is high use RPi.GPIO library for input pin
MOSFET
5V logic
needs 5V logic -> use level converter from 3.3V
best is external power for VCC
use heat sink if used with high current
it is best to place a diode parallel to the load
http://elinux.org/RPi_GPIO_Interface_Circuits#Using_a_FET
the MOSFET can be used to drive a standard 120mm computer fan (at 5V it runs nice and quiet)
Relay
3.3V logic, 5V relay
remove jumper and use 3.3V for logic and
5V (external power at best) for JDVCC
the relays activate on low level input use RPi.GPIO library for output pin
DS3231
3V-5V, I2C 0x68
sudo i2cdetect -y 0
echo ds3231 0x68 | sudo tee /sys/class/i2c-adapter/i2c-0/new_device
if neccessary change timezone
sudo raspi-config
to write time to hwclock
sudo hwclock -w
to check times
sudo hwclock -r
date
to load hwclock at startup
sudo nano /etc/rc.local
And write to the end of file before exit 0 (for Model B rev 1)
sudo echo ds3231 0x68 > /sys/class/i2c-adapter/i2c-0/new_device
sudo hwclock -s
if you want to disable NTP
sudo update-rc.d ntp disable
sudo update-rc.d fake-hwclock disable
to update time via NTP
sudo ntpd -gq
sudo hwclock -w
GY-30 BH150FVI Light Sensor
3V-5V, <1mA, I2C 0x23 connect addr to ground
http://www.raspberrypi-spy.co.uk/2015/03/bh1750fvi-i2c-digital-light-intensity-sensor/
Credit to Matt Hawkins from Raspberrypi-Spy
for usage and demo configure and run following file
wget https://bitbucket.org/MattHawkinsUK/rpispy-misc/raw/master/python/bh1750.py
nano bh1750.py
sudo python bh1750.py
Rotary Encoder
http://www.bobrathbone.com/raspberrypi_rotary.htm
Credit to Chris Bob Rathbone
mkdir /home/pi/sources/pi_rotary
cd /home/pi/sources/pi_rotary
wget http://www.bobrathbone.com/raspberrypi/source/pi_rotary.tar.gz
tar -xzvf pi_rotary.tar.gz
rm pi_rotary.tar.gz
sudo cp rotary_class.py /usr/local/lib/python2.7/dist-packages/rotary_class.py
If you have a revision 1 RPI comment the code as describe in the comments:
sudo nano /usr/local/lib/python2.7/dist-packages/rotary_class.py
see test_rotary_class.py and test_rotary_switches.py for usage
4x4 Membrane Matrix Keypad
http://crumpspot.blogspot.de/p/keypad-matrix-python-package.html
Credit to Chris Crumpacker
sudo pip install matrix_keypad
to see/change ROW and COLUMNS GPIO pins
sudo nano /usr/local/lib/python2.7/dist-packages/matrix_keypad/RPi_GPIO.py
Python usage
from matrix_keypad import RPi_GPIO
kp = RPi_GPIO.keypad(ColumnCount = 4)
def digit():
digitPressed = None
while digitPressed == None:
digitPressed = kp.getKey()
return digitPressed
DHT22 AM2302 temperature and humidity Sensor
3V-5V, <1mA
needs a 4.7k-10k Ohm resistor between data and VCC
https://learn.adafruit.com/dht-humidity-sensing-on-raspberry-pi-with-gdocs-logging/
Credit to Tony DiCola from Adafruit
cd /home/pi/sources
git clone https://github.com/adafruit/Adafruit_Python_DHT.git
cd Adafruit_Python_DHT
sudo python setup.py install
to get the readings in the shell (data pin = BCM 4)
sudo /home/pi/sources/Adafruit_Python_DHT/examples/AdafruitDHT.py 22 4
Python usage (data pin = BCM 4)
import Adafruit_DHT
pin = 4
humidity, temperature = Adafruit_DHT.read_retry(Adafruit_DHT.DHT22, pin)
if humidity is not None and temperature is not None:
print('Temp={0:0.1f}*C Humidity={1:0.1f}%'.format(temperature, humidity))
else:
print('Failed to get reading. Try again!')
WS2812 RGB Neopixel Ring
5V
needs an external 5V power supply (up to 60mA per LED)
place a 1000uF capacitor between VCC and Ground
needs 5V logic -> use level converter from 3.3V
connect with a 300-500 Ohm resistor between the data to the RPI PWM pin 18
https://learn.adafruit.com/neopixels-on-raspberry-pi/overview
Credit to Jeremy Garff and Tony DiCola from Adafruit
sudo apt-get install scons swig
cd /home/pi/sources
git clone https://github.com/jgarff/rpi_ws281x.git
cd rpi_ws281x
scons
cd python
sudo python setup.py install
for demo configure LED_COUNT in the example strandtest.py and run the file
sudo nano examples/strandtest.py
sudo python examples/strandtest.py
SSD1306 128x64 OLED Display
3V-5V, 0.08W max, I2C 0x3C
https://learn.adafruit.com/ssd1306-oled-displays-with-raspberry-pi-and-beaglebone-black/overview
Credit to Tony DiCola from Adafruit
sudo apt-get install python-imaging
cd /home/pi/sources
git clone https://github.com/adafruit/Adafruit_Python_SSD1306.git
cd Adafruit_Python_SSD1306
sudo python setup.py install
if the display doesn’t have an RST pin, comment all lines containing
self._rst in the SSD1306.py library
(for me lines: 87, 88 and 153-160)
sudo nano /usr/local/lib/python2.7/dist-packages/Adafruit_SSD1306-1.6.0-py2.7.egg/Adafruit_SSD1306/SSD1306.py
for demo configure and run the files in the example directory
HD44780 20x4 LCD with PCF8574
5V, I2C 0x27
needs 5V logic -> use level converter from 3.3V
https://learn.adafruit.com/character-lcd-with-raspberry-pi-or-beaglebone-black/overview
Credit to Tony DiCola from Adafruit and Sylvan Butler for the fork
we use this fork which supports the PCF8574:
cd /home/pi/sources
git clone https://github.com/sylvandb/Adafruit_Python_CharLCD.git
cd Adafruit_Python_CharLCD
sudo python setup.py install
sudo cp Adafruit_CharLCD/PCF_CharLCD.py /usr/local/lib/python2.7/dist-packages/PCF_CharLCD.py
python usage (busnum=1 for newer RPI)
import PCF_CharLCD
lcd = PCF_CharLCD.PCF_CharLCD(0, address=0x27, busnum=0, cols=20, lines=4)
lcd.message('Hello\nworld!')
custom character creator
http://www.quinapalus.com/hd44780udg.html
lcd.create_char(1, [2, 3, 2, 2, 14, 30, 12, 0])
lcd.clear()
lcd.message('Custom Character in Location 1: \x01')