How to Program the DDS Function Signal Generator

In principle, you can use any of the nominal value from 8 MHz to 16 MHz - you just have to put in a program the desired frequency. Resistor in the circuit 5 ohms. (From the left edge of the 7 pieces obtained by parallel connection of resistors 10 ohm - sealed sandwich). On board there are 4 jumpers 1206 a variable resistor to adjust the contrast of the display after the measurement is replaced by two fixed resistors. Due to the relative simplicity of the circuit elements on the circuit board and the pin numbers are not signed - easy to understand. On the right side of the chip displayed three pads for analog legs - two ADC inputs - just in case.

Now about the program. For the source program of Italian colleagues, mentioned in the first part of the article about the DDS signal generator kit has been applied. I removed most of the Italian words, changing them into more understandable English counterparts, and changed the principle of data output to the display. The main body of the program (cycle DO LOOP) consists of a reference to display the sub-programs, the survey keyboard and navigation on the display). For each menu item has its own sub-program uses the destination buttons, well, and, if desired, the user can tailor them to your wishes. As a conclusion of the data used to display an array of two strings of 16 characters in length, each of which I change values - numbers, letters, etc. The current position is indicated by a blinking cursor.

LF DDS generator currently generates 8 signals: standard - sine, square, sawtooth, triangle, and not very - pseudonoise, of cos-type function (x) * sin (5x) , damped sine wave and a square wave signal with a variable duty cycle increments ≈ 1%. The last three tables were accidentally found in the depths of the internet, and are inserted for collection - if desired, they can be changed to something more useful. The rectangular signal with variable duty cycle - a useful thing, and the subroutine was written under it. BTW, you can select the DDS signal generator kit at Banggood. Besides, you can easily get other electrical accessories (e.g. security tag hook key) there with high quality and reasonable prices.