In today’s tutorial I’ll explain you how to interface the esp32 chip to external devices (sensors, displays…) using a very widespread bus: the I2C bus. I2C I2C (pronounced i-squared-c) is a serial communication bus – invented by Philips in 1982 – that allows two or more devices to communicate. The devices connected to the bus can…
In some of the previous tutorials, I explained how to include “external” items (images, SSL certificates…) in your program thanks to the embedding binary data feature of the esp framework. Today I’ll show you how to use part of the flash memory to store data, like it was an hard drive or a memory card. Partitions and filesystem You’ve…
In this tutorial, divided in two posts, I’ll show you how to use RFID (Radio-frequency Identification) tags with Arduino. In the first part you’ll learn how to connect the reader to your Arduino and how to write a simple sketch to display the tag’s ID, while in the second part you’ll learn how to build a complete access control…
Wemos is a chinese manufacturer of IoT products, well known for its D1 Mini family, that includes boards based on the ESP-8266EX chip and expansion shields. Some weeks ago, Wemos announced a board based on the new ESP32 chip, named LOLIN32. This board hosts an ESP-WROOM-32 module and can be powered by a single cell (1S) LiPo battery. The board can…
STM32 is a family of 32bit microcontrollers manufactured by STMicroelectronics and based on the ARM Cortex M core. The STM32 family is divided into different lines of microcontrollers (L0-1-4, F0-1-2…) depending on their features and the use they are designed for: These microcontroller are widely used in the industrial world… for example both Pebble watches and Fitbit bracelets are based on STM32…
One of the most popular projects among the ones included in my tutorial about the enc28j60 chip is fore sure WebRelay. This project allows to control an output pin of Arduino using a simple web page, designed to be accessed also using your smartphone. Today I’m going to show you how to implement a similar project with the…
In today’s tutorial you’ll learn how to permanently store information, so that they are preserved even if the esp32 chip is reset or power is removed. NVS NVS (Non Volatile Storage) is a library included in the esp-idf framework that allows to store information (in the form of key/value) in the flash memory, the content of which is not erased…
On this blog I published several electronic projects and tutorials but I realized that none of those is about robotics; for this reason I’m going to start – with this post – a tutorial for dummies to teach how to build a small robot and how to program it to do different tasks, like avoid obstacles, follow a line, receive commands… To…
In all the examples so far, we used the esp32 chip in STAtion Mode, that is as a client which connects to an existing wifi network. In a previous article I explained in details how the different components of the esp-idf framework interact to establish the connection and how to use events to syncronize the tasks of your program. Today…
In embedded applications it’s often necessary a clock, as accurate as possible. For example, imagine a device that has to activate an output at a given time or a logger that has to store values (temperature…) at precise intervals. A solution widely adopted is the use of an RTC (Real Time Clock) chip. The problem…