Embedded Software Development with Python and the Raspberry Pi Class 4: Controlling Raspberry Pi Peripherals with Python August 21, 2014 Jacob Beningo, CSDP © All Images and content in this presentation may not be used or copied without express written permission of the owner.

Course Overview Introduction to Python Python Fundamentals An Overview of the Raspberry Pi Controlling Raspberry Pi Peripherals with Python An Internet of Things Weather Station Example

Session Overview Controlling Raspberry Pi Peripherals with Python The Raspberry Pi Ecosystem Library Setup GPIO Setup and Example I2C UART SPI Analog Sensors Pi Camera

Ecosystem

Library Setup Python Raspberry Pi Libraries Installation Steps Provide code modules to easily access hardware Easy to Install Installation Steps Update Packages Install GPIO Library Install git Install optional Adafruit Python Libraries

Library Setup – Update Packages sudo apt-get update

Library Setup – Install Python 2.7 sudo apt-get install python-dev

Library Setup – Install GPIO sudo apt-get install python-rpi.gpio

Library Setup - Optional Adafruit Libraries Useful interfaces for experimentation Install git sudo apt-get install git Clone Adafruit repository git clone http://github.com/adafruit/Adafruit-Raspberry-Pi-Python-Code.git cd Adafruit-Raspberry-Pi-Python-Code ls

Library Setup - Optional

A GPIO Example Goals Setup Toggle an LED using Python Adjustable blink rate Use of ctrl-c to exit application Setup Use nano GPIO18 as an output Use python sleep()

A GPIO Example

Setting Up I2C Add I2C modules sudo nano /etc/modules Don’t forget to reboot after this step! sudo reboot

Setting Up I2C Install I2C tools sudo apt-get install python-smbus sudo apt-get install i2c-tools Modify /etc/modprobe.d/raspi-blacklist.conf Don’t forget to restart after saving sudo reboot

Setting Up I2C sudo i2cdetect –y 1

Setting Up the UART UART0 by default is setup for Kernel Debugging

Setting Up the UART Run the UART Script Steps Disconnects the UART from Kernel Steps sudo wget https://raw.github.com/lurch/rpi-serial-console/master/rpi-serial-console -O /usr/bin/rpi-serial-console && sudo chmod +x /usr/bin/rpi-serial-console rpi-serial-console status Rpi-serial-console disable sudo reboot The script modifies the entries for ttyAMA0 in /boot/cmdline.txt /etc/inittab

Setting Up the UART Install python-serial Most likely already installed and up to date sudo apt-get install python-serial

Setting Up SPI Install Spi Wrapper mkdir python-spi cd python-spi wget https://raw.github.com/doceme/py-spidev/master/setup.py wget https://raw.github.com/doceme/py-spidev/master/spidev_module.c sudo python setup.py install

Setting Up SPI

Reading Analog Sensors Model: A / B / B+ Model: B+ Only

Reading Analog Sensors MCP3008 ADC Chip

Pi Camera Enable Camera Sudo raspi-config Reboot Python Test Script

Going Further Download Template Materials for Web Tutorials YouTube Python Doxygen Script Template Personal Weather Station Python Script Raspberry Pi Example Python Scripts Web Tutorials YouTube From www.beningo.com under Blog and Articles > Software Techniques > Embedded Software with Python

Contact Information P.O. Box 400 Linden, Michigan 48451 : jacob@beningo.com : 810-844-1522 : Jacob_Beningo : Beningo Engineering : JacobBeningo : Embedded Basics Jacob Beningo Principal Consultant © All Images and content in this presentation may not be used or copied without express written permission of the owner.