Alan Matheson / Mbed 2 deprecated AD9850

A port of AD9850/51 code from Arduino source. This port allows direct input of the frequency in Mega Hertz rather than a series of Hex digits as in Liam Goudges program.

Dependencies:   mbed

main.cpp@1:44d13dabc8e9, 2014-02-10 (annotated)

Committer:
alan_matheson
Date:
Mon Feb 10 00:17:37 2014 +0000
Revision:
1:44d13dabc8e9
Parent:
0:bea0000c5526 
AD9850 program ported from Arduino code by Alan Matheson

Who changed what in which revision?

UserRevisionLine numberNew contents of line
alan_matheson 0:bea0000c5526 1 #include "mbed.h"
alan_matheson 0:bea0000c5526 2
alan_matheson 0:bea0000c5526 3 /*
alan_matheson 1:44d13dabc8e9 4 * This program is a port of an AD9851 DDS Arduino sketch by Andrew Smallbone at www.rocketnumbernine.com
alan_matheson 1:44d13dabc8e9 5 * It was later modified for testing the inexpensive AD9850 ebay DDS modules
alan_matheson 0:bea0000c5526 6 * Pictures and pinouts at nr8o.dhlpilotcentral.com
alan_matheson 1:44d13dabc8e9 7 * AD9850 datasheet at http://www.analog.com/static/imported-files/data_sheets/AD9850.pdf
alan_matheson 0:bea0000c5526 8 * Use freely
alan_matheson 1:44d13dabc8e9 9 * Ported by Alan Matheson on 20 February 2014
alan_matheson 0:bea0000c5526 10 */
alan_matheson 0:bea0000c5526 11
alan_matheson 0:bea0000c5526 12
alan_matheson 0:bea0000c5526 13 //efine W2_CLK // connect to AD9850 module2 word load clock pin (CLK)
alan_matheson 0:bea0000c5526 14 //efine W1_CLK 12 // connect to AD9850 module1 word load clock pin (CLK)
alan_matheson 0:bea0000c5526 15 //efine FQ_UD p5 // connect to freq update pin (FQ)
alan_matheson 0:bea0000c5526 16 //efine DATA 10 // connect to serial data load pin (DATA)
alan_matheson 0:bea0000c5526 17 //efine RESET 9 // connect to reset pin (RST).
alan_matheson 0:bea0000c5526 18
alan_matheson 0:bea0000c5526 19 #define pulseHigh(pin) {pin = 1; pin = 0; }
alan_matheson 0:bea0000c5526 20
alan_matheson 1:44d13dabc8e9 21 // Pins used are the same as those used in the MBED driver for AD9850 digital synthesizer using hacked SPI interface
alan_matheson 1:44d13dabc8e9 22 // by Liam Goudge Sept 2013
alan_matheson 1:44d13dabc8e9 23 // This program allows the desired frequency in MegaHertz to be directly entered and uses bitbanging rather than the SPI pins.
alan_matheson 1:44d13dabc8e9 24
alan_matheson 0:bea0000c5526 25
alan_matheson 0:bea0000c5526 26
alan_matheson 0:bea0000c5526 27 // configure data pins for output
alan_matheson 0:bea0000c5526 28 DigitalOut FQ_UD(p8);
alan_matheson 0:bea0000c5526 29 DigitalOut W_CLK(p7);
alan_matheson 0:bea0000c5526 30 DigitalOut DATA(p5);
alan_matheson 0:bea0000c5526 31 DigitalOut RESET(p15);
alan_matheson 0:bea0000c5526 32
alan_matheson 0:bea0000c5526 33
alan_matheson 0:bea0000c5526 34
alan_matheson 0:bea0000c5526 35
alan_matheson 0:bea0000c5526 36 // transfers a byte, a bit at a time, LSB first to the 9850 via serial DATA line
alan_matheson 0:bea0000c5526 37 void tfr_byte_module1(char data)
alan_matheson 0:bea0000c5526 38 {
alan_matheson 0:bea0000c5526 39 for (int i=0; i<8; i++, data>>=1) {
alan_matheson 0:bea0000c5526 40 DATA = (data & 0x01);
alan_matheson 0:bea0000c5526 41 pulseHigh(W_CLK); //after each bit sent, CLK is pulsed high
alan_matheson 0:bea0000c5526 42 }
alan_matheson 0:bea0000c5526 43 }
alan_matheson 0:bea0000c5526 44
alan_matheson 0:bea0000c5526 45 void tfr_byte_module2(char data)
alan_matheson 0:bea0000c5526 46 {
alan_matheson 0:bea0000c5526 47 for (int i=0; i<8; i++, data>>=1) {
alan_matheson 0:bea0000c5526 48 DATA = (data & 0x01);
alan_matheson 0:bea0000c5526 49 pulseHigh(W_CLK); //after each bit sent, CLK is pulsed high
alan_matheson 0:bea0000c5526 50 }
alan_matheson 0:bea0000c5526 51 }
alan_matheson 0:bea0000c5526 52
alan_matheson 0:bea0000c5526 53
alan_matheson 0:bea0000c5526 54 // frequency calc from datasheet page 8 = <sys clock> * <frequency tuning word>/2^32
alan_matheson 0:bea0000c5526 55 void sendFrequency(double frequency) {
alan_matheson 0:bea0000c5526 56 int32_t freq = frequency *1e6 * 4294967295/125000000; // note 125 MHz clock on 9850
alan_matheson 0:bea0000c5526 57 for (int b=0; b<4; b++, freq>>=8) {
alan_matheson 0:bea0000c5526 58 tfr_byte_module1(freq & 0xFF);
alan_matheson 0:bea0000c5526 59 }
alan_matheson 0:bea0000c5526 60 tfr_byte_module1(0X38); // Final control byte, all 0 for 9850 chip
alan_matheson 0:bea0000c5526 61 }
alan_matheson 0:bea0000c5526 62
alan_matheson 0:bea0000c5526 63
alan_matheson 0:bea0000c5526 64 int main()
alan_matheson 0:bea0000c5526 65 {
alan_matheson 0:bea0000c5526 66 double frequency;
alan_matheson 0:bea0000c5526 67
alan_matheson 0:bea0000c5526 68 // Initialise the AD9850 module
alan_matheson 0:bea0000c5526 69 pulseHigh(RESET);
alan_matheson 0:bea0000c5526 70 pulseHigh(W_CLK);
alan_matheson 0:bea0000c5526 71 pulseHigh(FQ_UD); // this pulse enables serial mode - Datasheet page 12 figure 10
alan_matheson 0:bea0000c5526 72
alan_matheson 0:bea0000c5526 73
alan_matheson 0:bea0000c5526 74 while(1)
alan_matheson 0:bea0000c5526 75 {
alan_matheson 1:44d13dabc8e9 76 frequency = 7.080;
alan_matheson 1:44d13dabc8e9 77 sendFrequency(frequency);
alan_matheson 1:44d13dabc8e9 78 pulseHigh(FQ_UD);
alan_matheson 1:44d13dabc8e9 79 wait(5.0);
alan_matheson 1:44d13dabc8e9 80 }
alan_matheson 0:bea0000c5526 81 }
alan_matheson 0:bea0000c5526 82
alan_matheson 0:bea0000c5526 83 }
alan_matheson 0:bea0000c5526 84
alan_matheson 0:bea0000c5526 85