DDS Signal generator Based on AVR

This AVR DDS generator was designed to generate signals from 1Hz up to 65535Hz with various waveform and frequency.

The AVR DDS signal generator consist of the 8-bit Atmel ATmega8 microcontroller which contains 8kb of flash program memory and 16MHz of maximum frequency used for reaching DDS generators maximum resolution. The generator contains a 2×16 standard LCD that is controlled using 3 wires through shift register 74HC164. To save microcontroller pins, this shift register is used as serial to parallel converter while the LCD is controlled in 8-bit mode.

The generator contains 3 outputs including universal DAC output through R-2R ladder that forms various signals like sawtooth, sine, square, and triangle. The timer directly forms the PWM signal output. The square pulse or second PWM signal will be formed by the additional SQ channel or impulse. A 9V battery is used to power the DDS AVR generator as the voltage is stabilized and reduced by the 7805 voltage regulator to 5V. There are 7 control buttons used that manipulates the device.

C language is used to write the program as the programming is done by using AVR ISP and PonyProg programming software.

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