The STM32 is equipped with an extremely flexible General Purpose Input Output (or GPIO) peripheral allowing to configure each Input/Output independently. The IO is the simplest interface between the STM32 and the outside world.
As we said in the article “From 0 to STM32“, there are many versions of the same peripherals across the various STM32’s sub-families and this is way each sub-family usually has its own Reference Manual. In this document it is possible to find all the functional information about GPIO and reading many RM we can notice that GPIO peripheral has three continue reading...
In this article, we are going to take a deep look to ChibiOS default demos explaining how they work. We will also see how to create a new project and how to modify it in in order to create our own applications.
A ChibiOS’ default demo is usually composed of some different folders and files. For example, in figure, we can see the resources of the default demo for STM32 Nucleo F401RE. In general, all the ChibiOS’ projects are characterized by similar anatomy.
All demos have some folders, some configuration headers, a source file named main.c and a makefile. Additional continue reading...
Nowadays, we are surrounded by smart objects capable to do incredible things. These objects, known as Smart Things, are now able to communicate over different wired and wireless communication channels. The obvious consequence is that these objects are able to get and to push data through the Internet: this phenomenon, this network of Smart Things, is commonly known as the Internet of Things or IoT.
The spreading of the IoT is substantially due to two main con-causes:
the evolution of Microcontrollers which are increasing their performances while their price is continue reading...
HC-SR04 is a commonly used ultrasonic sensor which is capable to detect obstacles in a range of 2-300cm. The sensor looks like a small PCB having two metal cylinders on the front-side and a small circuit on the back-side (see Fig.1).
In this article we will provide a simple demo to use HC-SR04. This requires a preliminary read of the sensor user manual:
HC-SR04 User Manual
The sensor has 4 PIN:
VCC, which must be connected to 5V;
Trig, which is an input PIN to trigger the measurement;
Echo, which is an output PIN which sent out a square wave;
GND, which must be continue reading...
The HD44780 is a de-facto standard controller for display. We have already use it providing a source code to use a 16×2 LCD with a STM32. In this article we will step over introducing an I2C backpack for that display. Of course we will explain how to edit old code in order to get it work with this new hardware configuration.
Even if it is still popular, this controller was made commercially available in the late eighties. At that time serial communications were not so widespread because their were costly and involved constraint about clock speed. Because of that, the continue reading...