Overview A Pulse Width Modulation (PWM) output from a PIC microcontroller can be used to play tones on a piezo speaker. With this, musical scales and simple songs can be played on the piezo speaker. Piezoelectric speakers operate by the converse piezoelectric effect: when a voltage is applied across the terminals, the piezoelectric material in …
Driving a piezo speaker with a PIC using pic-microcontroller, Read More »
Introduction This project implements a real-time audio spectrum analyser using a PIC18F4550 8-bit microcontroller. The spectrum frequency analysis is performed by a highly optimised 16-bit Fast Fourier Transformation (FFT) routine coded entirely in C. The output from the FFT is displayed using a 128×64 graphical LCD to allow a real-time view of an audio signal. …
Recently a cell phone ring tone was in the news – it’s 17,000 Hertz and meant to be heard by teenagers, but inaudible to adults. Really got some people upset for some reason. It got me wondering – what frequencies can I hear? I made the shrieker. It can generate tones from 10,000 Hz to …
We’ve implemented an autonomous pursuit vehicle capable of chasing a designated target using ultrasonic transmissions. The system is demonstrated by chasing a second, human-controlled, RC car. The pursuit unit is equipped with a 24kHz transmitter and two 40kHz receivers, while the target unit has a 24kHz receiver and a 40kHz transmitter. The target unit responds …
Introduction This project visually displays the frequency content of an audio signal using an 8X3 grid of LEDs. A microphone and amplifier collect analog audio input which is sampled digitized using the MCU’s analog-digital converter. The samples are buffered and and a 32 point discrete cosine transform is performed in real time to obtain 32 …
In this project we built a sketchpad based on LED matrix display with microcontroller and resistive touch screen control. We used a single point resistive touch screen to detect the user’s gesture and microcontroller’s analog/digital converter (ADC) ports collects the data and convert it to coordinates. We designed a LED drive circuit with shift registers …
