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Getting started with mikroe BUZZ Click using ChibiOS/HAL

Getting started with mikroe BUZZ Click using ChibiOS/HAL

BUZZ Click is a click board with a mikroBus form factor. It is substantially composed of a piezoelectric speaker having a resonant frequency at 3.8 kHz: this means we should expect best performances at this frequency. Let’s take a look to the principle of operation of DC and AC buzzer.

A piezoelectric loudspeaker also known as buzzer uses the inverse piezoelectric effect for generating sound. The piezoelectricity is a phenomena where mechanical stress produces the accumulation of electrical charges and then a voltage across the material. The inverse principle is true continue reading...

Capacitive touchpad and ST Nucleo

Capacitive touchpad and ST Nucleo

The TTP229 is an integrated circuit for capacitive sensing designed specifically for touch pad controls. It provides stable sensing method covering different conditions.

The chip is a TSSOP-28 deigned to work with 8 or 16 key. It provide a direct interface if we use it in 8 key mode providing an output for pin for every key (So 8 direct output). When we want to use it in 16 key mode, the TSP229 provides a serial interface. We can find two different version of the TTP229: BSF and LSF. Main difference is in serial communication: TTP229BSF uses a 2 wire serial, TTP229LSF continue reading...

How to use an HD44780 based Liquid Crystal Display

How to use an HD44780 based Liquid Crystal Display

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...

Sampling and dimming (ADC and PWM)

Sampling and Dimming

An Analog to digital converter is a device that converts a continuous physical quantity (usually voltage) to a digital number that represents the quantity’s amplitude.

In this demo, we are sampling voltage across a potentiometer to establish its position. A potentiometer is a three-pin knob that provides a variable resistance between W-A and W-B pins (Fig.1). Amount of resistance between A and B is constant, but by turning the shaft of the potentiometer, we change the amount of resistance on either side of W.

Connecting A to 3 V, B to GND (or vice versa) and sampling continue reading...