book

Practical Python Programming for IoT

by Gary Smart

November 2020

Intermediate to advanced

516 pages

11h 24m

English

Packt Publishing

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Practical Python Programming for IoT
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Who this book is forWhat this book coversTo get the most out of this bookDownload the example code filesCode in ActionDownload the color imagesConventions usedGet in touchReviews
Technical requirementsUnderstanding your Python installationSetting up a Python virtual environmentInstalling Python GPIO packages with pipAnatomy of a virtual environmentAlternative methods of executing a Python scriptUsing sudo within virtual environmentsExecuting Python scripts outside of their virtual environmentsRunning a Python script at bootConfiguring the GPIO interface on our Raspberry PiConfiguring the PiGPIO daemonSummaryQuestionsFurther reading
Technical requirementsCreating a breadboard prototype circuitUnderstanding the breadboardPositioning and connecting the push buttonPositioning and connecting the LEDPositioning and connecting the resistorReading an electronic schematic diagramReading the push button schematic connectionReading the LED and resistor schematic connectionIntroducing ground connections and symbolsExploring two ways to flash an LED in PythonBlinking with GPIOZeroImportsPin Factory configurationBlinking the LEDBlinking with PiGPIOImportsPiGPIO and pin configurationBlinking the LEDComparing the GPIOZero and PiGPIO examplesExploring two ways to integrate a push button in PythonResponding to a button press with GPIOZeroImportsButton pressed handlerButton configurationPreventing the main thread from terminatingResponding to a button press with PiGPIOButton pin configurationButton pressed handlerCreating your first IoT programRunning and testing the Python serverUnderstanding the server codeImportsVariable definitionsThe resolve_thing_name() methodThe get_lastest_dweet() methodThe poll_dweets_forever() methodThe process_dweet() methodThe main program entry pointExtending your IoT programImplementing a dweeting buttonPiGPIO LED as a classSummaryQuestions Further reading
Technical requirementsIntroducing the Flask microservices frameworkCreating a RESTful API service with Flask-RESTfulRunning and testing the Python serverUnderstanding the server codeImportsFlask and Flask-RESTful API instance variablesGlobal variablesThe init_led() methodServing a web pageThe LEDControl classThe get() class methodThe post() class methodLEDController registration and starting the serverIntroduction to PWMAdding a RESTful API client web pageUnderstanding the client-side codeJavaScript importsThe getState() functionThe postUpdate() functionThe updateControls() functionRegistering event handlers with jQueryThe web page HTMLCreating a Web Socket service with Flask-SocketIORunning and testing the Python serverServer code walkthroughImportsFlask and Flask-RESTful API instance variablesServing a web pageConnecting and disconnecting handlersLED handlerStarting the serverAdding a Web Socket client web pageUnderstanding the client-side codeImportsSocket.IO connect and disconnect handlersThe on LED handlerThe document ready functionThe web page HTMLComparing the RESTful API and Web Socket serversSummaryQuestionsFurther reading
Technical requirementsInstalling the Mosquitto MQTT brokerLearning MQTT by examplePublishing and subscribing MQTT messagesExploring MQTT topics and wildcardsApplying Quality of Service to messagesRetaining messages for later deliveryPublishing a retained messageCreating durable connectionsSaying goodbye with a WillUsing MQTT broker servicesIntroducing the Python Paho-MQTT client libraryControlling an LED with Python and MQTTRunning the LED MQTT exampleUnderstanding the codeImportsGlobal variablesThe set_led_level(data) methodThe on_connect() and on_disconnect() MQTT callback methodsThe on_message() MQTT callback methodThe init_mqtt() methodMain entry pointBuilding a web-based MQTT clientUnderstanding the codeImportsGlobal variablesThe Paho JavaScript MQTT clientConnecting to the brokerThe onConnectionLost and onMessageArrived handler methodsJQuery document ready functionSummaryQuestionsFurther reading

Technical requirementsUnderstanding Raspberry Pi pin numberingExploring popular Python GPIO librariesReviewing GPIOZero – simple interfacing for beginnersReviewing RPi.GPIO – a low-level GPIO for beginnersReviewing Circuit Python and Blinka – interfacing for complex devicesReviewing PiGPIO – a low-level GPIO libraryExploring remote GPIO with PiGPIO (and GPIOZero)Reviewing SPIDev and SMBus – dedicated SPI and I2C librariesWhy PiGPIO?Exploring Raspberry Pi electronic interfacing optionsUnderstanding digital IOUnderstanding analog IOUnderstanding Pulse-Width ModulationCreating PWM signalsUnderstanding SPI, I2C, and 1-wire interfacesUnderstanding the serial / UART protocolInterfacing with an analog-to-digital converterBuilding the ADS1115 ADC circuitMaking sure the ADS1115 is connected to your Raspberry PiReading analog input with the ADS1115Understanding the codeImportsADS1115 setup and configurationGlobal variablesProgram entry pointUsing PWM to control an LEDUnderstanding the codeGlobal variablesRange mapping functionGenerating the PWM signalVisually exploring PWM with PiScopeVisualizing software and hardware-timed PWMSummaryQuestionsFurther reading
Technical requirementsFitting out your workshopBuying electronic modules and componentsPurchasing lose componentsPurchasing open source hardware modulesKeeping your Raspberry Pi safeThree ways electronic components failElectronics interfacing principles for GPIO controlOhm's Law and powerKirchhoff's circuit lawsWhy are we using a 200 Ohm resistor for the LED circuit?Calculating the resistor valueFactoring in the Raspberry Pi's current limitsCalculating the resistor's power dissipationExploring digital electronicsDigital outputDigital inputUsing pull-up and pull-down resistorsThe resistor solutionThe code solutionExploring analog electronicsAnalog outputAnalog inputVoltage dividersUnderstanding logic-level conversionVoltage dividers as logic-level convertersLogic-level converter ICs and modulesComparing voltage dividers and logic-level convertersSummaryQuestionsFurther reading
Technical requirementsExploring a relay driver circuitDetermining a load's voltage and currentMeasuring the current requirement of a DC motorMeasuring the current requirement of a relay and LEDUsing an optocoupler as a switchBuilding the optocoupler circuitControlling the optocoupler with PythonUsing a transistor as a switchBuilding the MOSFET circuitControlling the MOSFET with PythonUsing a relay as a switchBuilding the relay driver circuitControlling the Relay Driver Circuit with PythonSummaryQuestionsFurther reading
Technical requirementsMaking color with an RGB LED and PWMCreating the RGB LED circuitRunning and exploring the RGB LED codeControlling a multi-color APA102 LED strip with SPICreating the APA102 circuitPowering the APA102 circuitConfiguring and running the APA102 LED strip codeAPA102 LED strip code walkthroughDiscussion of APA102 and the SPI interfaceAPA102 LED strip troubleshooting tipsUsing an OLED displayConnecting the OLED displayVerifying whether the OLED display is connectedConfiguring and running the OLED exampleOLED code walkthroughMaking sound with buzzers and PWMBuilding the RTTTL circuitRunning the RTTTL music exampleSummaryQuestionsFurther reading
Technical requirementsMeasuring temperature and humidityCreating the DHT11/DHT22 circuitRunning and exploring the DHT11/DHT22 codeDetecting lightCreating an LDR light-detecting circuitRunning the LDR example codeLDR code walkthroughLDR configuration summaryDetecting moistureComparing detection optionsSummaryQuestions
Technical requirementsUsing PWM to rotate a servoConnecting a servo to your Raspberry PiHow a servo is controlled using PWMRunning and exploring the servo codeDifferent types of servosUsing an H-Bridge IC to control a motorBuilding the motor driver circuitRunning the example H-Bridge code to control a motormotor.pymotor_class.pyIntroduction to stepper motor controlConnecting the stepper motor to the L293D circuitRunning and exploring the stepper motor codeSummaryQuestions
Technical requirementsDetecting movement with a PIR sensorCreating the PIR sensor circuitRunning and exploring the PIR sensor codeMeasuring distance with an ultrasonic sensorHow an ultrasonic distance sensor worksHC-SR04 distance measurement processBuilding the HC-SR04 circuitRunning and exploring the HC-SR04 example codeDetecting movement and distance with Hall-effect sensorsCreating a Hall-effect sensor circuitRunning and exploring the Hall-effect sensor codeSummaryQuestions
Technical requirementsBuilding and testing our circuitBuilding the reference circuitRunning the examplesExploring the event-loop approachExploring a threaded approachExploring the publisher-subscriber alternativeExploring an AsyncIO approachAn asynchronous experimentSummaryQuestionsFurther reading
Technical requirementsTriggering an IFTTT Applet from your Raspberry PiCreating the temperature monitoring circuitCreating and configuring an IFTTT AppletTriggering an IFTTT WebhookTriggering an IFTTT Applet in PythonActioning your Raspberry Pi from an IFTTT AppletMethod 1 – using the dweet.io service as an intermediaryMethod 2 – creating a Flask-RESTful serviceCreating the LED circuitRunning the IFTTT and LED Python programCreating the IFTTT AppletControlling the LED from an emailIFTTT troubleshootingVisualizing data with the ThingSpeak platformConfiguring the ThinkSpeak platformConfiguring and running the ThinkSpeak Python programOther IoT and automation platforms for further explorationZapierIFTTT platformThingsBoard IoT platformHome AssistantAmazon Web Services (AWS)Microsoft Azure, IBM Watson, and Google CloudSummaryQuestions
Technical requirementsOverview of the IoT Christmas treeBuilding the IoTree circuitThree IoTree service programsConfiguring, running, and using the Tree API serviceConfiguring the Tree API serviceRunning the Tree API serviceConfiguring, running, and using the Tree MQTT serviceConfiguring the Tree MQTT serviceRunning the Tree MQTT service programIntegrating the IoTree with dweet.ioConfiguring the Tree MQTT serviceRunning the dweet integration service programIntegrating with email and Google Assistant via IFTTTIntegration with emailIntegration with Google AssistantIdeas and suggestions to extend your IoTreeSummaryQuestions
Chapter 1Chapter 2Chapter 3Chapter 4Chapter 5Chapter 6Chapter 7Chapter 8Chapter 9Chapter 10Chapter 11Chapter 12 Chapter 13Chapter 14
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Overview

Practical Python Programming for IoT is your hands-on guide to building innovative Internet of Things projects using Python and Raspberry Pi. Through practical examples and step-by-step instructions, you'll learn how to connect physical hardware to the web seamlessly, while mastering IoT communication technologies like MQTT, REST APIs, and WebSockets.

What this Book will help me do

Understand Raspberry Pi and Python interfaces for IoT applications.
Design and implement RESTful, MQTT, and WebSocket communication systems.
Utilize sensors and actuators for practical hardware projects.
Explore advanced Python techniques for efficient IoT development.
Integrate IoT systems with visualization and automation platforms like IFTTT.

Author(s)

Gary Smart is a seasoned developer and educator specializing in IoT systems and Python programming. With extensive experience in designing and implementing robust connected systems, Gary aims to make complex technical concepts accessible to enthusiasts and professionals. His passion for bridging software with hardware shines through in his approachable teaching style.

Who is it for?

This book is ideal for individuals aiming to delve into IoT, including developers, engineers, and students with basic Python knowledge. It's accessible for enthusiasts new to hardware yet comprehensive for professionals seeking to refine their skills. Whether you're aiming to enhance automation in your projects or explore IoT development, this resource meets diverse needs.