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...
The HD44780 is a controller for display developed by Hitachi commonly used to manage alphanumeric dot matrix LCD. This controller is a standard de-facto for this kind of display. It is often used in industrial test equipment, networking equipment, vending machine and in embedded projects.
Compatible LCD screens are manufactured in several standard configurations. Common sizes are one row of eight characters (1×8), as well as 16×2, 20×2 and 20×4 formats. Larger custom sizes are made with 32, 40 and 80 characters and with 1, 2, 4 or 8 lines. The most commonly manufactured continue reading...