Design and Implementation of A Signal Generator By Using Direct Digital Synthesis Technique

Abstract

A PIC microcontroller is a main processor to generate four types of waveforms. This device has two channels output which not only provides user’s editable waveform (sine, square, triangular, sawtooth etc) but also indicates user’s frequency. The waveform synthesis is based on the Direct Digital Synthesis (DDS) technique to provide high stability and accuracy. The synthesized digital values at the port of the microcontroller are converted to an analog waveform by an 8-bit DAC. This signal generator can generate Sine, Square, Triangle and Sawtooth waveforms. It can operate standalone or with a personal computer (PC). A dot-matrix LCD is used to display the information about the waveform and the frequency selection. The type of waveform and the frequency selection can be selected from the embedded keypad or PC. The waveform table can be uploaded from the PC to the generator. The generator stores the received waveform table in the FLASH memory and uses it to generate waveform.