MORE ABOUT Arduino

Sensors are a worthwhile topic to write about: They bring electronics projects in contact with the real world and facilitate all kinds of practical applications. Dogan Ibrahim describes more than 40 projects in this comprehensive book.

This circular wall clock comes as a partially assembled kit. It is presented in the form of a simple ring of about 25 cm (10 inches) diameter, to hang on the wall. In fact, all you see is this sober black crown a few centimetres in size, which acts as the dial. No display, no hands, no second hand, no pendulum, nothing like that. And yet, like all good timepieces, this one does have hands, a second hand, and even a pendulum.

This new Elektor book describes how an Android mobile device can communicate with a variety of hardware platforms — including Raspberry Pi, Arduino, and the ESP32 processor — over a Wi-Fi link or by using SMS text messages. All the Android projects in this book were developed using the B4A programming language.

Single-board computers such as the Raspberry Pi and the Arduino are now commonplace whether in industry or at home, and are gaining popularity. Espressif's ESP8266 has also established itself both within the scene and at Elektor with its comprehensive functionality at a low price. The ESP32 is the new big brother sporting a dual-core processor, Bluetooth, more RAM and I/O extensions.

In the last episode, we configured the ESP32 to set up its own local Wi-Fi network. With a PC, smartphone or tablet, we are able to log into this network called ‘ESP32_MyJourneyIoT’ and request a configuration page from the ESP32 web server using a web browser. To show successful hook up we light up an LED. In this episode we change the indicator light to a pulsing LED and write our own class library.

The Pretzel board is a really useful tool especially when you are starting out with networks. Now however it was time to try out a different type of board. We took a look at the ESP32 which is the more powerful cousin of the ESP8266 with many more peripheral functions built-in...

The ESP8266 from Espressif has made waves in the maker community with its low price: you can get one from AliExpress for just two or three euros/ dollars/pounds. Its big brother, the ESP32, is the result of Espressif’s efforts to make their WLAN SoCs fit for the future. Along with a dual-core processor, it has onboard Bluetooth, more RAM, and IO extensions. In this article we talk about programming the ESP32 with the Arduino IDE. In the next issue of Elektor we will turn our attention to the native development tool IDF.