40MHz DDS VFO Programable Module

This board will control one of the small AD9850 DDS modules available on eBay. It supports a 16x2 line LCD display showing the operating frequency, band and step size. The frequency can be adjusted using either a rotary encoder or two push buttons. Two additional buttons are used to select the frequency band and frequency step size.

Menu system allowing setting the

• IF Frequency
• IF Offset (VFO+IF, VFO-IF, IF-VF0)
• Minimum Frequency & Maximum Frequency
• Reference Oscillator Calibration and Factory Reset
• Additional Band settings

You need to add the following items to this kit

• The AD9850 (5 volt) module (available on eBay)
• Two or four push-buttons

All the components are mounted on a high quality double sided silk-screened fiber glass printed circuit board. Full set of instructions with circuit and wiring

• operating frequency range 0-40MHz in 1Hz-1MHz steps (assumes VFO+IF mode)
• frequency setting by rotary encoder or two push buttons
• frequency band setting by push button (LOW,160M,80M,40M,30M,20M,17M,15M,12M,10M)
• frequency step setting by push button (1Hz,10Hz, 100Hz,1KHz,5KHz,10KHz,100KHz,1MHz)
• full menu system for setting user defined parameters
• IF frequency and IF offset (VFO+IF, VFO-IF, IF-VFO), minimum and maximum frequency range
• restores last frequency, last band, last step size and all user settings, on power up
• 32 bit arithmetic calculations for highest accuracy
• calibration function implemented in software and factory reset
• designed to control the 20 pin plug-in AD9850 DDS 5 Volt Modules (user supplied)
• designed to control a 16x2 line LCD display (user supplied)
• PIC Processor with EEPROM, software written in assembler using Microchip MPLAB

• pcb size 85mm x 40mm
• high quality double side pcb with solder mask and silk screen
• pre-programed PIC16F628A micro-controller
• on-board voltage regulator for 5v plug-in module
• input voltage 9 to 12 volts DC (polarity protected)