Monthly Archives: January 2011


PIC microcontroller based audio spectrum analyzer

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This project introduces a real-time audio spectrum analyzer based on a PIC18F4550 microcontroller. The spectrum frequency analysis is done with a 16-bit Fast Fourier Transformation (FFT) routine coded in C. It uses a 128×64 GLCD to display the FFT waveform of a live audio signal. “In order to perform a FFT calculation on an audio signal it is necessary to prepare the audio so the PIC18F4550 can sample the signal. The PIC18F4550 provides several analogue to digital converters (ADCs) which can be used to measure a voltage from 0V to 5V with 10-bit accuracy (0-1023). A typical audio line-out signal

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Programmable digital timer switch using a PIC Microcontroller

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Digital timer switches are used to control the operation of electrical devices based on a programmed schedule. This project describes a programmable digital timer based on the PIC16F628A microcontroller that can be programmed to schedule the on and off operation of an electrical appliance. The appliance is controlled through a relay switch. This timer switch allows you to set both on and off time. That means, you can program when do you want to turn the device on and for how long you want it to be remained on. The maximum time interval that you can set for on and

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Lab 9: Pulse Width Modulation (PWM) using PIC CCP module

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Description Pulse width modulation (PWM) is a technique of controlling the amount of power delivered to an electronic load using an on-off digital signal. The fraction of the period for which the signal is on is known as the duty cycle. The average DC value of the signal can be varied by varying the duty cycle. The duty cycle can be anywhere between 0 (signal is always off) to 1 (signal is constantly on). Suppose, if the signal has +5 V while it is on and 0 V during off condition, then by changing the duty cycle of the signal,

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