Harry Fairhead

The Espressif ESP32 is a remarkable device. It is low cost but with many different subsystems that make it more powerful than you might think. You can use it for simple applications because it is cheap, but you can also use it for more sophisticated applications because it is capable. C is the ideal choice of language to program the ESP32, ensuring that your programs are fast and efficient, and here it is used with the Espressif IoT Development Framework, ESP-IDF and VS Code, a combination which makes it simple to get started and provides a wealth of functions not found elsewhere.

The purpose of this book is to reveal what you can do with the ESP32's GPIO lines together with widely used sensors, servos and motors and ADCs. After covering the GPIO, outputs and inputs, events and interrupts, it gives you hands-on experience of PWM (Pulse Width Modulation), PWM for Motor control, the SPI bus, the I2C bus and the 1-Wire bus, the UARTs and of course WiFi. To round out, it covers direct access to the hardware, adding an SD Card reader, sleep states to save power, the RTC, RMT and touch sensors. It also devotes a chapter to FreeRTOS which takes us into the realm of asynchronous processing. This is not a projects book, although there isn’t much left for you to do to round out the embryonic projects that are used as examples. Instead it is about understanding concepts and the acquisition of skills. The hope is that by the end of the book you will know how to tackle your own projects and get them safely to completion without wasting time in trial and error. Harry Fairhead is the co-author of Programming the ESP32 in MicroPython, but C is his programming language of choice and electronics is his forte. He is the author of Fundamental C: Getting Closer To The Machine and Applying C For The IoT With Linux. His other books on programming single-board computers include Programming the Raspberry Pi Pico/W in C; Raspberry Pi IoT In C; Raspberry Pi IoT in C With Linux Drivers and Micro:bit IoT in C.

There is a new edition of this book: Programming The Raspberry Pi Pico/W In C, Second Edition. The Raspberry Pi Pico is a remarkable microcontroller. It has a power and sophistication that would have been unthinkable just a short time ago. For the sort of jobs it is ideal for, it has plenty of processing power and enough memory to make tasks that would have once required careful planning, relatively easy. Instead of struggling with the machine, you can now focus on getting a good implementation of your algorithms. To enjoy all of its power and sophistication there is no better language than C.

It wastes none of the power and it gives you what you need to get at the new features. However, getting started with the Pico with C is no easy feat, which is what motivated this book about creating programs so that testing and debugging is easy. Programming the Raspberry Pi Pico in C uses the highly popular VS Code as its development environment and shows how to use a Raspberry Pi or a desktop PC running Windows as your development machine. The purpose of the book is to reveal what you can do with the Pico's GPIO lines together with widely used sensors, servos and motors and ADCs. After covering the GPIO, outputs and inputs, events and interrupts, it gives you hands-on experience of PWM (Pulse Width Modulation), the SPI bus, the I2C bus and the 1-Wire bus. One of the key advantages of the Pico is its PIO (Programmable I/O) and while this is an advanced feature it is included in this book. After finding out how the PIO works, we apply it to writing a PIO program for the DHT22 and the 1-Wire bus. One current drawback of the Pico it is that it doesn’t have a network connection. To solve this problem there is a chapter on using the low-cost ESP8266 as a WiFi client and web server. The two devices together make the Pico a true IoT device. Harry Fairhead has a hardware background and, having worked with microprocessors and electronics in general, for many years, he is an enthusiastic proponent of the IoT and embedded computing. He is the author of two books intended for C programmers, Fundamental C: Getting Closer To The Machine and Applying C For the IoT With Linux and four books on the using the Raspberry Pi in an IoT context, two using C and two using Python. He is now working on a Python version of this book for the Pico.

Reviews of the previous edition:. "A complete explanation that makes it straightforward to interface I/O options to the Pi. Good examples are easy to follow and well explained - starting with "Hello World" and then walks through the various interface options available with GPIO. I highly recommend this to anyone using the Pi for any embedded system application requiring various types of interfaces.". "This is the book to read to get deep into Raspberry IoT. Programming examples are provided. Great book!". The Raspberry Pi makes an ideal match for the Internet of Things.

But to put it to good use in IoT you need two areas of expertise, electronics and programming and, because of the way hardware and software engineering tend to occupy separate niches, you may need help with combining the two which is the role of this book. This 3rd Edition was prompted by the arrival of the Pi 5. Unfortunately, as the Pi 5 uses the new RP1 chip to implement its peripherals, it is incompatible with all of the IoT libraries that work directly with the hardware. As a result it is excluded from much of this book. A whole chapter is, however, devoted to getting started with an IoT project with the Pi 5 and it is also covered in chapters on the Linux GPIO driver and on the use of the Pi’s serial ports and in a chapter, which describes how to access the Pi 5’s registers directly. What is more important than the Pi 5 from the point of view of IoT is the Pi Zero 2W, which is a much faster, quad-core, version of the Pi Zero W making it an excellent choice for IoT projects. It is covered for the first time in this edition. Another reason for a new edition is to update its programs to the new versions of Pi OS, Bookworm and Bullseye. Finally, a major change is that VS Code is now the book’s IDE of choice and to make it easy to use as a remote development environment with all versions of Pi from Pi Zero to Pi 5, a set of custom VS Code tasks are supplied, which are downloadable as well as included in the book. The main idea in this book is to work directly with the hardware using the Raspberry Pi's GPIO (General Purpose Input Output) to connect with off-the-shelf sensors. After reading it you will be in a better position to tackle interfacing anything-with-anything without the need for custom drivers and prebuilt hardware modules. Harry Fairhead has worked with microprocessors and electronics for many years and is an enthusiastic proponent of the IoT. C is his programming language of choice and he has written several books on programming the Raspberry Pi and other devices in an IOT context, including Raspberry Pi IoT in C With Linux Drivers, Second Edition, Programming the ESP32 in MicroPython and Fundamental C: Getting Closer To The Machine. Currently, his most popular title is Programming the Raspberry Pi Pico/W in C.

Adding WiFi to the Raspberry Pi Pico turns this low-cost, small form factor device into a true IoT device. The extra capabilities added to the Pico W open up loads of opportunities, but only if you are prepared to do battle with the two libraries that provide networking and security – lwIP and mbedtls respectively. The problem with these large libraries of code is that they are poorly documented and don’t refer directly to the Pico W and its SDK. This book sets out to remedy this by providing a guide to these libraries along with examples of what you can do with them.

Having introduced the Pico WiFi Stack and basic network connections, we look at how to use TCP to create the all-important Protocol Control Block and then tackle implementing an HTTP client. As well as covering the basic mechanics of using lwIP, we also concentrate on how to organize the use of an asynchronous library based on callbacks. The problem of IoT security is unique because IoT devices can be physically accessed by an attacker and hence any secrets embedded in their code have to be considered almost as public knowledge. Even so it is worth implementing encryption and this is achieved using mbedtls to create an HTTPS client. If you can ensure the physical security of the IoT device, then running it as a server is possible and this is covered in both HTTP and HTTPS modes, complete with certificates. We cover the basics of cryptography, including the problem of generating random numbers, what an encryption suite is and the various modes of AES encryption. The later chapters are devoted to specific protocols, making use of both lwIP and mbedtls. We look at UDP; SNTP to set the Pico W’s real time clock; SMTP to allow email notifications and MQTT. Harry Fairhead is also the author of Programming The Raspberry Pi Pico/W In C; Raspberry Pi IoT in C, Raspberry Pi IoT In C Using Linux Drivers, Applying C For The IoT With Linux, Fundamental C: Getting Closer To The Machine and Micro:bit IoT in C. Mike James is the author of Programming the Raspberry Pi Pico/W in MicroPython; Raspberry Pi IoT In Python Using GPIO Zero; and the Programmer's Python: Something Completely Different series of books and several other programming and computer science titles in the I Programmer Library.

The Raspberry Pi makes an ideal match for the Internet of Things. But to put it to good use in IoT you need two areas of expertise, electronics and programming and because of the way hardware and software engineering tend to occupy separate niches, you may need help with combining the two which is what this book sets out to do. Python is an excellent language for learning about physical computing. It might not be as fast as C, but it is much easier to use for complex data processing. One reason for Python’s popularity is its wealth of supporting libraries and there are several for interfacing hardware.

The GPIO Zero library is the official way to use Python with the GPIO and other devices and this book looks at how to use it to interface to fundamental IoT devices – from LEDs and buzzers to servos and stepper motors and several off-the-shelf Raspberry Pi add-ons. This revised second edition had been expanded to cover all the current Raspberry Pis including the latest, the Pi 5, and the Pi Zero 2W which, with its WiFi capability and being a quad-core device, is an ideal device for IoT projects. It has also been updated to cover the latest version of the GPIO Zero library, which is both the library recommended by Raspberry Pi and the only one that works with the Pi 5. The emphasis in this book is about using and understanding the hardware and GPIO Zero. It not only shows you how to “follow the beaten track”, but how to create your own tracks. While it isn’t a project book, many of the code examples described are part way to projects and all of the devices and techniques described can be used to create practical projects. Similarly while it doesn’t teach you the whole of Python, it does bring you up to speed in the aspects of the language needed for interfacing with hardware. Harry Fairhead has worked with microprocessors, and electronics in general, for many years and is an enthusiastic proponent of the IoT. He is the author of Raspberry Pi IoT in C, which has recently been republished in its third edition, and Raspberry Pi IoT in C Using Linux Drivers, now in its second edition. Mike James is the co-author Raspberry Pi IoT in Python Using Linux Drivers, Second Edition. He is also the author of the Programmer's Python: Something Completely Differentseries of books.

The ESP32 is a remarkable device. It is low cost but with many different subsystems that make it more powerful than you might think. You can use it for simple applications because it is cheap, but you can also use it for more sophisticated applications because it is capable. MicroPython is a good choice of language to program the ESP32. Although it is a slower language than C, most of the time this doesn’t matter and it is much easier to use. As a high-level language, MicroPython is based on Python 3 and is fully object-oriented. In general, you can take an existing Python 3 program and simply run it under MicroPython.

If there are any changes to make, they are generally minor. Another good thing about MicroPython on the ESP32 is that it is very easy to get started. After a simple installation procedure you have a working MicroPython machine which you can program almost at once using the Thonny IDE or PyCharm which has more extensive syntax checking and input prompting. The purpose of the book is to reveal what you can do with the ESP's GPIO lines together with widely used sensors, servos and motors and ADCs. After covering the GPIO, outputs and inputs, events and interrupts, it gives you hands-on experience of PWM (Pulse Width Modulation), the SPI bus, the I2C bus and the 1-Wire bus. We also cover direct access to the hardware, adding an SD Card reader, sleep states to save power, the RTC, RMT and touch sensors, not to mention how to use WiFi. The ESP32 has so many resources that a comprehensive account would fill a book twice this size. In order to make things fit in the space available we have concentrated on things that are accessible from MicroPython and that are basic to getting started. We have avoided “advanced” topics which generally lead the beginner into deep water far too quickly. However, we do cover of use of uasyncio, and asynchronous programming, in general as they are essential to networking. Jointly authored by Harry Fairhead and Mike James, this book combines Harry’s expertise in electronics and the IoT with Mike’s knowledge of Python. Their previous books include Programming the Raspberry Pi Pico/W in MicroPython, Raspberry Pi IoT In Python, Raspberry Pi IoT In Python Using Linux Drivers while Harry Fairhead is the author of the C language counterparts. His other books include Fundamental C: Getting Closer To The Machine, Applying C For The IoT With Linux, and Micro:bit IoT in C. Mike James is the author of theProgrammer's Python: Something Completely Different series of books and several other programming and computer science titles in the I Programmer Library.

UPDATED AND EXTENDED SECOND EDITION, COVERING BOTH ORIGINAL AND V2 NOW AVAILABLE. The BBC micro:bit is capable of taking on a variety of roles including that of a powerful IoT device. In order to gain full access to its features and to external devices, however, you need to use C which delivers the speed crucial to programs that communicate with the outside world. Written for the electronics enthusiast, micro:bit IoT In C starts with a first “Hello Blinky” C program with the mbed online compiler, we move to the desktop to using an offline approach using the yotta development environment plus NetBeans to make things even easier.

Now we are ready to discover how to control the micro:bit’s I/O lines, exploring the basis of using the GPIO. For speed, however, we need to work directly with the raw hardware and also master memory mapping, pulse width modulation and other more sophisticated bus types. From here we can start connecting sensors using first the I2C bus, then by implementing a custom protocol for a one-wire bus, and eventually adding eight channels of 12-bit AtoD with the SPI bus, which involves overcoming some subtle difficulties. We then look at serial connections, one of the oldest ways of connecting devices but still very useful. The micro: bit lacks WiFi connectivity but using a low-cost device we enable a connection to the Internet via its serial port which allows it to become a server. To conclude we look at the micro:bit’s LED display. This may only be 5x5, but it is very versatile, especially when you use pulse width modulation to vary the brightness level, something we demonstrate in a classic game, written of course in C.

Third Edition Now Available. The Raspberry Pi makes an ideal match for the Internet of Things. But to put it to good use in IoT you need two areas of expertise, electronics and programming and, because of the way hardware and software engineering tend to occupy separate niches, you may need help with combining the two. This book teaches you to think like an IoT programmer. In Raspberry Pi IoT in C you will find a practical approach to understanding electronic circuits and datasheets and translating this to code, specifically using the C programming language.

The main reason for choosing C is speed, a crucial factor when you are writing programs to communicate with the outside world. If you are familiar with another programming language, C shouldn't be hard to pick up. This Second Edition has been brought up-to-date and focuses mainly on the Pi 4 and the Pi Zero. There is new material on the recently introduced GPIO character driver and using the Pi 4’s additional ports and scheduling. Although NetBeans is used to develop programs, VS Code is now considered an alternative remote development environment and all the book’s code, which is available for download, has been tested with VS Code. The main idea in this book is to not simply install a driver, but to work directly with the hardware using the Raspberry Pi's GPIO (General Purpose Input Output) to connect with off-the-shelf sensors. It explains how to use its standard output with custom protocols, including an in-depth exposition of the 1-wire bus. You will also discover how to put the Internet into the IoT using sockets. After reading this book you will be in a better position to tackle interfacing anything-with-anything without the need for custom drivers and prebuilt hardware modules. Harry Fairhead has worked with microprocessors and electronics in general for many years and is an enthusiastic proponent of the IoT. As well as being the Editor of IoT-Programmer.com, he is a regular contributor to I‑Programmer.info, where he covers all aspects of hardware. His other recent books include Applying C For The IoT With Linux as well as Fundamental C: Getting Closer To The Machine and Micro:bit IoT in C.

Applying C is the book you need if you are programming for Single Board Computers (SBCs) that run Linux, or if you do any coding in C that interacts with the hardware. As there isn’t a good name for this body of knowledge, it isn’t easy to find a single source for it. This book gathers together all of these low-level, hardware-oriented and often hardware-specific ideas. As such it is a moderately advanced book. This is not to say that it is difficult, but it does presuppose that you already know how to program in C and that you know the basic idioms of C.

Starting off from the very simple task of making a program run automatically, we look at how your program works with user-mode Linux. If you are working with hardware, arithmetic cannot be ignored and separate chapters are devoted to integer, fixed-point and floating-point arithmetic. Equally, to handle I/O you need to have a good grasp of files and the pseudo file system. The dev/mem file coupled with memory-mapped files makes it possible to work with raw memory without leaving user mode. Sockets are general-purpose way of communicating over networks and similar infrastructure and here the focus is on sending data over the internet and for this we build a web client and a server. Next we consider graphics, which you might find unusual in a book on small systems, but today even small systems have GPUs and graphics comes as standard. It is common to think of adding low-cost output devices such as 7-segment displays to IoT devices, but with low cost HDMI/DVI displays available it becomes cost effective to simply use the built-in graphics hardware. After this we turn to the idea of multi-tasking using Pthreads. As well as looking at threads, we consider locking, using mutex and condition variables, and scheduling. Although interrupts don't exist in user-mode Linux, we can get very close using poll and threading. Now that multiple cores are a feature of even low-cost SBC, in later chapters we cover managing cores, look at C11’s atomics and introduce its memory models and barriers. Finally we take a short look at how to mix assembler with C. Harry Fairhead has a hardware background and, having worked with microprocessors and electronics in general, for many years, he is an enthusiastic proponent of the IoT. He is the author of Fundamental C: Getting Closer To The Machine and his other recent titles include Raspberry Pi IoT in C and Micro:bit IoT in C.

The Raspberry Pi makes an ideal match for the Internet of Things. To put it to good use in IoT you need two areas of expertise, electronics and programming and this presents a barrier to getting started. However, there is an overlooked route that can provide a shortcut. Pi OS, the Raspberry Pi’s operating system is Linux based and Linux drivers are available for many off-the-shelf IoT devices. These provide a very easy-to-use, high-level way of working. The problem that this book solves is that there is very little documentation to help you get started.

In it Harry Fairhead explains the principles so that you can tackle new devices and he also guides you through using external hardware via standard Linux drivers. Throughout this book you will find a practical approach to understanding electronic circuits and datasheets and translating this to code, specifically using the C programming language. This second edition was prompted by the advent of the Pi 5, welcomed as the fastest member of the Raspberry Pi family. What came as a shock is that, from the point of view of IoT, it is incompatible with all other Raspberry Pis due to the use of a custom chip. Luckily, although the Pi 5 cannot work with the standard IoT libraries it does behave in the same way under Linux drivers and so this new book does include the Pi 5 on an equal footing. Coverage also includes the Pi Zero 2W, which has a quad-core chip making it more capable than both the original Pi Zero and the WiFi-enabled Pi ZeroW. After a quick tour of the Raspberry Pi ecosystem, Visual Studio Code (VS Code) and how it can be used to develop remotely, is introduced. The first IoT program anyone writes is “blinky” to flash an LED and this book is no exception, but it might not be quite what you expect. Instead of using a GPIO line it uses the Linux LED driver – no hardware and no fuss. The GPIO isn’t left out, however, as the next three chapters focus on its use via the new GPIO character driver. A key component in any look at Linux and its relationship to hardware is the device tree. While most accounts of this resource are aimed at device driver writers, this one is aimed at device driver users and to this end we look at the DHT22 temperature and humidity driver. After a brief detour into some basic electronics, we look at Pulse Width Modulation supported via a driver rather than needing to be implemented using the GPIO. From here we tackle the two standard buses, I2C and SPI, first going through the basics and then looking at the two attempts to impose a higher organization, the hardware monitoring system, hwmon, and Industrial I/O, IIO. We also look at the 1-Wire bus. The final chapter takes things to the next level and considers creating your own custom overlays by writing fragments to the device tree. Harry Fairhead has worked with microprocessors and electronics in general for many years and is an enthusiastic proponent of the IoT. C is his programming language of choice and he has written several books on programming the Raspberry Pi and other devices in an IOT context, including Raspberry Pi IoT In C, 3rd Edition, Programming the Raspberry Pi Pico/W in C, 2nd Edition, Programming the ESP32 in MicroPython and Fundamental C: Getting Closer To The Machine.

There is a new edition of this book. The Raspberry Pi makes an ideal match for the Internet of Things. To put it to good use in IoT you need two areas of expertise, electronics and programming, and this presents a barrier to getting started. However, there is an overlooked route that can provide a shortcut. Pi OS, the Raspberry Pi’s operating system, is Linux- based and Linux drivers are available for many off-the-shelf IoT devices. These provide a very easy-to-use, high-level, way of working. The problem that this book solves is that there is very little documentation to help you get started.

Throughout this book you will find a practical approach to understanding electronic circuits and datasheets and translating this to code, specifically using Python. Python is an excellent language for learning about the IoT or physical computing. It might not be as fast as C, but it is much easier to use for complex data processing. The emphasis in this book is on understanding how things work so that you can apply your new knowledge to your own projects. You can use any Python development system that you know, but the programs in the book have been developed using Visual Studio Code and its remote development facilities. The first IoT program anyone writes is “Blinky” to flash an LED and this book is no exception, but it might not be quite what you expect. Instead of using a GPIO line, it uses the Linux LED driver – no hardware and no fuss. The GPIO isn’t left out, however, as the next three chapters focus on its use via the new GPIO character driver, which replaces the old and very common sysfs GPIO driver. This is the way to do modern GPIO. A key component in any look at Linux and its relationship to hardware is the relatively new Device Tree. While most accounts of this resource are aimed at device driver writers, this one is aimed at device driver users and to this end we look at several devices, including the DHT22 temperature and humidity sensor. After a brief detour into some basic electronics, we see how Pulse Width Modulation is supported via a driver. From here we tackle the two standard buses, I2C and SPI, first going through the basics and then looking at the two attempts to impose a higher organization, the hardware monitoring system, Hwmon, and Industrial I/O, IIO. The third standard bus, although generally not supported in hardware, is the 1-Wire bus. This is covered in detail and even includes an introduction to using Netlink, which uses the sockets API to send messages to and from the kernel to access the driver. The final chapter takes things to the next level and considers creating your own custom overlays by writing fragments to the device tree. This is the second title jointly authored by Harry Fairhead and Mike James and can be seen as the alternative approach to that outlined in Raspberry Pi IoT In Python Using GPIO Zero. For both books, Harry brings his expertise in electronics and the IoT and Mike contributes the Python code. Harry Fairhead is the author of other IoT-related titles including Raspberry Pi IoT in C, Second Edition; Micro:bit IoT in C, Second Edition; Applying C For The IoT With Linux and Fundamental C: Getting Closer To The Machine. Mike James is the author of Programmer's Python: Everything is an Objectand other programming and computer science titles in the I Programmer Library.