After having published my tutorial about sending SMS with the ESP32, I received some comments via the contact form of my website asking a way to send notifications for free. Today I’ll show you a way to do it; it will be also the occasion to write about IFTTT service and about developing custom components for the…
When you surf on the Internet, the DNS (Domain Name System) service has the job of “translating” (resolve) the hostnames to the corresponding IP addresses. If, for example, you type www.google.com in your favorite browser, your computer queries the DNS server – usually the one managed by your provider – and gets from it the IP…
On 6th of April, Espressif published version 2.0 of the esp-idf framework. The complete list of the new features and the bugs fixed is available on Github, let’s see the most important ones (in my opinion ;)): [checklist] they included or made stable new drivers for peripherals like I2C, I2S, SPI Master, SDMMC you can now run a serial…
When designing and developing an embedded application, you often need to implement a way to notify the user if a specific event or condition is reached. Let’s imagine for example an house alarm system that must inform the owner if the front door is open when he’s away… In today’s tutorial I’ll show you how…
In a previous blog post, I started explaining how to use the esp32 pins for Input/Output operations. Today I’ll show you how to take advantage of the interrupts the pins can generate. Interrupts In computer technology, an interrupt is a signal that indicates the occurrence of a specific event which requires immediate attention. The interrupt signal therefore blocks the normal…
After having published my previous article, I received some comments asking what was the purpose of a random number generator, like the one included in the esp32 chip. Random numbers are widely used in cryptography and a good random number generator is very important to assure an high level of security, as well-explained in Cloudflare’s…
Today a short tutorial that will explain how to use the random number generator, a peripheral included in the esp32 chip. It’s also an opportunity to show how to interact with internal peripherals and to understand some additional details about how the framework is designed. Address space Both the esp32 CPUs (PRO e APP) share (with some minor…
With this tutorial we’re going to start using the I/O pins of the esp32 chip. The chip features 40 General Purpose I/O pads (GPIO), that are 40 “contacts” you can use in different ways, both for input and output functions. The setup of those pads is quite complex: the esp32 chip allows indeed to “map” the internal…
After having learned how to connect your esp32 chip to a wifi network, today I’m going to show you how to send and receive data. lwIP The esp-idf framework includes the lwIP library to implement the TCP/IP stack protocol. This library, originally developed by Adam Dunkels and now maintained by a community of developers with an opensource license, is very…
You’ve already learned in the previous tutorials that all the configuration of the esp-idf framework is done using a configuration menu: You can use the same menu to set options/parameters for the program you’re developing: in today’s tutorial I’m going to explain how to do it! Kconfig The framework‘s config menu is configured via some…