Textbook in PDF format The main aim of this book is to teach the Arduino IDE and MicroPython programming languages in ESP32 based projects, using the highly popular ESP32 DevKitC development board. Many simple, basic, and intermediate level projects are provided in the book using the Arduino IDE with ESP32 DevKitC. All projects have been tested and work. Block diagrams, circuit diagrams, and complete program listings of all projects are given with explanations. In addition, several projects are provided for programming the ESP32 DevKitC using MicroPython. Microcontrollers are very popular electronic chips and are commonly used in many domestic, commercial, and industrial electronic monitoring and control applications. It is estimated that there are more than 50 microcontrollers in every house in developed countries. Some domestic equipments that have embedded microcontrollers are microwave ovens, printers, keyboards, computers, tablets, washing machines, dish washers, smart televisions, mobile phones, and many more. A tiny chip called the ESP8266 has recently made it possible to interface any type of microcontroller to a Wi-Fi AP. The ESP8266 is a low-cost tiny Wi-Fi chip that has a full built-in TCP/IP stack and a 32-bit microcontroller unit. This chip, produced by Shanghai based Chinese manufacturer Espressif System is IEEE 802.11 b/g/n Wi-Fi compatible with on-chip program and data memory, and general purpose input-output ports. Several manufacturers have incorporated the ESP8266 chip in their hardware products (e.g. ESP-xx, NodeMCU etc) and offer these products as a means of connecting a microcontroller system such as the Android, PIC microcontroller or others to a Wi-Fi. The ESP8266 is a low-power chip and costs only a few dollars. In addition to their ESP8266 chip, the same company has recently developed a new microcontroller chip named the ESP32. This is big brother of the ESP8266 and can be used in all projects that the ESP8266 is currently used. In addition to all the ESP8266 features, the ESP32 provides Bluetooth communications capability, larger SRAM data memory, more GPIOs, more interface signals, touch sensor, temperature sensor, higher CPU speed, CAN bus connectivity, higher resolution ADC converters, DAC converters, and security features. The projects provided in this book are designed to teach the following features of the ESP32 processor: GPIOs Touch sensors External interrupts Timer interrupts I?C and I?S SPI PWM ADC DAC UART Hall sensor Temperature sensor Infrared controller Reading and writing to SD card Reading and writing to flash memory RTC timer Chip ID Security and encryption Wi-Fi and network programming Bluetooth BLE programming Communication mobile devices Low power design ESP-IDF programming The projects have been organized with increasing levels of difficulty. Readers are encouraged to tackle the projects in the order given. A specially prepared hardware kit (SKU 18305) is available from Elektor. With the help of this hardware, it should be easy and fun to build the projects in this book