A very practical and easy to follow book to get first hand IoT knowledge using Raspberry Pi Pico. It teaches you how to add simple sensors like temperature sensor (AHT20) and use it for a gardening project. Likewise, it teaches you how to build air quality monitoring application. Very useful book for those seeking hands on knowledge.

Review written for Chapter 2 Serial Interfaces and ApplicationsBook Target Audience: Raspberry Pi Pico beginnersBeginner Note 1: Raspberry Pi Foundation released the Raspberry Pi Pico W with Bluetooth and 2.4GHz WiFi capabilities. The chapter reviewed uses ESP32 micro-controller to provide wireless communication capabilities to the then wireless version of the Raspberry Pi Pico on the market. Not much will change for beginners with the introduction of the Raspberry Pi Pico W as the Python programming frameworks used in this book will soon support the Raspberry Pi Pico W chip they chose to provide wireless capabilities, the Infineon CYW43439 chip natively.Beginner Note 2: As a beginner you may not possess much skills in programming micro controllers. This is why this book has made the decision to use the Python frameworks available for common micro controllers including the Raspberry Pi Pico. This book also uses sensor modules and displays that as a beginner you will need to purchase to complete the example projects. Prices are listed in the chapter but with the supply chain issues that are ongoing during the publishing of this book the prices you pay as a beginner may fluctuate from the printed prices within the book until the supply chain issues resolve. Prices for a given sensor can be indicative of but not necessarily relied on as a predictor of quality of a particular sensor as the less expensive mass produced sensors may be less precise but less expensive to purchase. As a beginner be aware that use of any given sensor is a design decision for whatever the end product or end purpose is. If you only need general temperature information for example a less expensive and less precise temperature sensor would suffice.Serial Interfaces are the most common interfaces users of micro controllers will use to communicate with the various sensor modules and even to other micro controllers such as the ESP32 used in this chapter to provide WiFi communication capabilities to any micro controller that does not already possess them. This is a very important chapter to pay attention to as a beginner.Wiring diagrams are provided in the form of Fritzing schematics which are at a high level and show color coded wire connections for the beginner to easily understand,. Rest assured there are no complicated circuit diagrams to learn.Serial communications technologies taught in this chapter include UART which will teach you asynchronous communications communications where there is no reference clock signal so both the micro controller and the device being communicated with must speak at an identical given speed, known as baud rate and then moves on to I2C invented by Philips Semiconductors in 1982 where one wire will carry the clock signal that all devices can reference so no need to separately set up a separate baud rate configuration and then covers the SparkFun QWIIC and AdaFruit STEMMA 3.3 volt and 5 volt respectively connector standards that build on top of I2C that allows users to daisy-chain different sensor boards together instead of using breadboards and wires to connect everything. The final serial communications standard covered is Serial Peripheral Interface (SPI) used by memory devices, sensors, displays and so on. As a beginner do not worry the coverage is not in depth to the point you will get lost but if you do wish to learn more there are links to external resources that are provided for those hungry for more information. The chapter ends with the interfacing a Raspberry Pi Pico with an ESP32 micro controller using SPI so that the Raspberry Pi Pico can borrow the wireless capabilities of the ESP32 micro controller to send and receive data on its behalf.The programming code is short. As a beginner most of it should be easy enough to understand, just be aware that some of the numbers provided will be in hexadecimal format, those with start with a "0x" before the actual number itself and then you will have normal numbers that will be easier for a beginner to comprehend.The heavy lifting of connecting the Raspberry Pi Pico to various sensors will already be done for you within the Python framework and any of the various libraries that have been written for a given sensor. You will not be required to understand lower level concepts in programming. If you do wish to further your education then the beginner is recommended to explore the Arduino Framework and Arduino IDE which give you some more control at a lower level of the micro controller and sensors.The writing style used in the chapter was clear and comprehensible.Overall as a book targeted towards the beginner the book provides enough for someone new to Raspberry Pi Pico to get their feet wet and experience various technologies used in the micro controller space. The program code provides the bare minimum to accomplish the communication technology being explained. There will not be completed complex applications, that is left to the beginner to analyze what their own specific problems or desires are and then try to make the Raspberry Pi Pico and any chosen sensors do what the beginner dreams up. If you are intermediate to advanced in IOT or micro controllers this is not written for you, it is for the beginners just getting their feet wet.

This book provides clear and concise guidance for audiences from beginner to advanced levels that wish to expand their knowledge of the Raspberry Pi pico platform. For the new learner you will be up and running code within hours and for the advanced learner the book provides code examples and instructions for many complex and advanced builds. Jason Russell - Gray Hat Guy LLC