Edited version june 2019

This is a usefull and easy to build VFO/DDS generator for Chinese AD9850/51 DDS modules

* Attention: be aware, i have tested only the AD9850 type module.

Design based on VK5TM  with PIC 16F628 and LCD 2x16 characters

Software modification by G4FDN - added band frequency's.

Specifications :

- Frequency from 0 to theoretically 62MHz (Software go to 62MHz, usefull limit for AD9850 is +/- 45MHz)
- Step size 1Hz, 10Hz, 100Hz, 1kHz, 10kHz, 100kHz, 1MHz
- Band frequency 0Hz, 137.5kHz, 472 kHz, 1.800 kHz, 3.500 kHz, 5.258 kHz, 7.000 kHz, 10.100 kHz, 14.000 kHz, 18.068 kHz, 21.000 kHz, 24.890kHz
- Remember the last used frequency
- Rotary encoder (mechanical)
- LCD 2x16 digits in 4-bit mode
- 3 push buttons : step size, Bandfreq, spare
- PIC 16F628 programmable µ-processor

My PCB board without the Chinese Module	Chinese Module details

The Intention was to control and to use of the cheap Chinese modules on the market.
Based original op the Pic-El Board, modifyed by VK5TM  and whithout the various extra's.

Circuit:

Print circuits :
I made a new circuit board so i can connect the LCD module directly on the board.
A Chinese module can be placed on the board. Power consumtion is abbout 120mA,
so a power-adaptor 240V to 9V AC 1A  is recommanded.

DDS Module + CPU Board	The LCD Display, rotary en PB's

DDS VFO in an old RS-232 switch-box - working state	DDS VFO   inside box

** The original GREEN backlight LED's in the LCD are replaced by WHITE LED's to have lower current consumption **

Software :

All software and print circuit in one ZIP file (after click, see in your Folder "Downloads") :  DDS_VFO_9850.zip