In my previous tutorial I explained how to use the I2C driver included in the esp-idf framework to communicate with I2C devices. Today I’ll show you a pratical example: the use of a temperature/humidity sensor. The sensor For this tutorial I chose the HTU21D sensor by Te Connectivity. This sensor offers a good level of accuracy and…
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 addition to the love for electronics, in my (little) spare time I’m working with my friend Davide on a model railway in H0 scale; in particular my main task is to take care of the digital control of locos, turnouts and accessories. The de facto standard to digitally control a model railway is named DCC (Digital Command Control);…
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…
After having published my post about how to implement a webserver on the esp32 chip, some readers correctly warned me that everyone, once connected to the wifi network, could control the relay and asked me how to limit access to the webpage. A classic solution (that I also used in this previous tutorial) is to ask the user…
If you follow my blog, you probably noticed that I use different online services to make my PCBs… it’s a way to test them in terms of quality and production time. On the advice of my friend Mauro, I recently chose PCBWay to produce some PCBs for my future projects. The procedure for sending a new order is…
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…
Some weeks ago I blogged about my project of a minimal board based on the CH340G chip. After some tests, I slightly modified the project: [checklist] I added two leds that blink when data are transmitted/received I added a jumper that allows to decide if you want power supply (5V) in the connector or not added a 10nF capacitor to make…
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…