Digital Function Generator (MEGA16-P)

Posted on Jun 8, 2012

The function generator features two BNC outputs : one for the high speed [1 to 8 MHz] square signal (BNC1) and another for the DDS signal (BNC2). Offset and amplitude can be regulated by two potentiometers : offset in range of +5V to -5V (POT1) and amplitude in range of 0 to 10V (POT2). Up and down arrow buttons are used for changing the function type (sine, triangle etc.) while left and right arrow buttons are used for changing the frequency value. There is also a separate menu for changing frequency step. When the middle button is pressed, the signal generation starts. Middle button is pressed again for stopping the signal. More details can be found in the original site.

Digital Function Generator (MEGA16-P)
Click here to download the full size of the above Circuit.

Because of the present LCD character orientation, which is different from the original implementation (180 degrees), the following changes in main.c were made : Buttons LEFT and RIGHT were reversed : #define LEFT 3//PORTD #define RIGHT 1//PORTD Buttons TOP and BOTTOM were reversed : #define DOWN 4//PORTD #define UP 0//PORTD For the latest version of AVR-GCC compiler, the following changes should be made (according to Geoff comment on : struct signal{ volatile uint8_t mode; //signal volatile uint8_t fr1; //Frequency [0..7] volatile uint8_t fr2; //Frequency [8..15] volatile uint8_t fr3; //Frequency [16..31] volatile uint32_t freq; //frequency value volatile uint8_t flag; //if 0 generator is OFF, 1 is ON volatile uint32_t acc; //accumulator volatile uint8_t ON; volatile uint8_t HSfreq; //high speed frequency [1...4Mhz] volatile uint32_t deltafreq; //frequency step value }SG; The ATMEGA16 fuses should be : HIGH = 0×59 LOW = 0xCF This is interpreted to the following options checked (all others unchecked) : OCDEN SPIEN BOOTSZ1 BOOTSZ2 SUT1 SUT0

Leave Comment

characters left:

New Circuits



Popular Circuits

Synchronous Stepdown Switching Regulator Circuit
Audio Oscillator with Frequency Counter
TV remote control blocker/jammer circuit diagram
Im trying to repair a Samsung SCR-3000 DVR COMBO for my security
Low Voltage to 30 kV Out
Constant Current LED Drive
LED Dance Pad
Audio AGC amplifier circuit