SonicMEMS@Cornell / Mbed 2 deprecated mBed_AD9833

Basic AD9933

Dependencies:   mbed

main.cpp@0:c5d5930ea5e7, 2014-11-26 (annotated)

Committer:
pc445
Date:
Wed Nov 26 18:21:15 2014 +0000
Revision:
0:c5d5930ea5e7
AD9833

Who changed what in which revision?

UserRevisionLine numberNew contents of line
pc445 0:c5d5930ea5e7 1 /////////////////////////////////////////////////////////////////////////
pc445 0:c5d5930ea5e7 2 // AD9833 control code
pc445 0:c5d5930ea5e7 3 // Create by Po-Cheng Chen 07-04-2014
pc445 0:c5d5930ea5e7 4 // Version 0.1
pc445 0:c5d5930ea5e7 5 /////////////////////////////////////////////////////////////////////////
pc445 0:c5d5930ea5e7 6
pc445 0:c5d5930ea5e7 7 #include "mbed.h"
pc445 0:c5d5930ea5e7 8 #include "SPI.h"
pc445 0:c5d5930ea5e7 9 #include "DigitalOut.h"
pc445 0:c5d5930ea5e7 10
pc445 0:c5d5930ea5e7 11 SPI AD9833_SPI(p5, p6, p7); //mosi, miso, sclk --> don't need MISO
pc445 0:c5d5930ea5e7 12 DigitalOut fSync(p8); //use p8 as FSync data pin (same as chip select)
pc445 0:c5d5930ea5e7 13
pc445 0:c5d5930ea5e7 14 /////////////////////////////////////////////////////////////////////////
pc445 0:c5d5930ea5e7 15 // SPI initialization
pc445 0:c5d5930ea5e7 16 /////////////////////////////////////////////////////////////////////////
pc445 0:c5d5930ea5e7 17 void SPI_INITIALIZATION()
pc445 0:c5d5930ea5e7 18 {
pc445 0:c5d5930ea5e7 19 //Setup the spi for 16 bit data, with 25MHz clock rate, mode 2
pc445 0:c5d5930ea5e7 20 // Note: mBed is MSB first SPI protocol
pc445 0:c5d5930ea5e7 21 AD9833_SPI.format(16,2);
pc445 0:c5d5930ea5e7 22 AD9833_SPI.frequency(25000000);
pc445 0:c5d5930ea5e7 23 fSync = 1;
pc445 0:c5d5930ea5e7 24 wait_ms(10);
pc445 0:c5d5930ea5e7 25 }
pc445 0:c5d5930ea5e7 26 /////////////////////////////////////////////////////////////////////////
pc445 0:c5d5930ea5e7 27 // SPI writing
pc445 0:c5d5930ea5e7 28 /////////////////////////////////////////////////////////////////////////
pc445 0:c5d5930ea5e7 29 void write_SPI(short dat)
pc445 0:c5d5930ea5e7 30 {
pc445 0:c5d5930ea5e7 31 fSync = 0;
pc445 0:c5d5930ea5e7 32 AD9833_SPI.write(dat);
pc445 0:c5d5930ea5e7 33 fSync = 1;
pc445 0:c5d5930ea5e7 34 }
pc445 0:c5d5930ea5e7 35 /////////////////////////////////////////////////////////////////////////
pc445 0:c5d5930ea5e7 36 // Set desired frequency
pc445 0:c5d5930ea5e7 37 // Comments:Calculate the desired frequency accrodingly
pc445 0:c5d5930ea5e7 38 // Do it in Matlab or mBed?
pc445 0:c5d5930ea5e7 39 /////////////////////////////////////////////////////////////////////////
pc445 0:c5d5930ea5e7 40 void setFreq(long FREQ)
pc445 0:c5d5930ea5e7 41 {
pc445 0:c5d5930ea5e7 42 int freq_MSB; //define freq MSB reg value
pc445 0:c5d5930ea5e7 43 int freq_LSB; //define freq LSB reg value
pc445 0:c5d5930ea5e7 44
pc445 0:c5d5930ea5e7 45 long freq_cal; //define freq calculated value
pc445 0:c5d5930ea5e7 46 float freq_val = 0.00000000; //define ferq calculate tempotary value
pc445 0:c5d5930ea5e7 47
pc445 0:c5d5930ea5e7 48 //calculate the frqe reg value
pc445 0:c5d5930ea5e7 49 //((desired frequency)/(reference frequency)) x 0x10000000.
pc445 0:c5d5930ea5e7 50 freq_val = (((float)(frequency))/25000000);
pc445 0:c5d5930ea5e7 51 freq_cal = freq_val*0x10000000;
pc445 0:c5d5930ea5e7 52
pc445 0:c5d5930ea5e7 53 freq_MSB = (int)((freq_cal & 0xFFFC000)>>14); // shift 14 bits
pc445 0:c5d5930ea5e7 54 freq_LSB = (int)(freq_cal & 0x3FFF);
pc445 0:c5d5930ea5e7 55
pc445 0:c5d5930ea5e7 56 freq_MSB = freq_MSB | 0x4000; //assign freq reg address
pc445 0:c5d5930ea5e7 57 freq_LSB = freq_LSB | 0x4000;
pc445 0:c5d5930ea5e7 58 ///////////////////////////////////////////////////////////////////////////////////
pc445 0:c5d5930ea5e7 59 //print the data from the serial port to verifiy the function
pc445 0:c5d5930ea5e7 60 printf("freq_LSB 0x%x\n\r", freq_LSB);
pc445 0:c5d5930ea5e7 61 //print the data from the serial port to verifiy the function
pc445 0:c5d5930ea5e7 62 printf("freq_MSB 0x%x\n\r", freq_MSB);
pc445 0:c5d5930ea5e7 63 ///////////////////////////////////////////////////////////////////////////////////
pc445 0:c5d5930ea5e7 64 write_SPI(0x2100); //write control reg - apply reset
pc445 0:c5d5930ea5e7 65 write_SPI(freq_LSB); //write freq reg - LSB
pc445 0:c5d5930ea5e7 66 write_SPI(freq_MSB); //write freq reg - MSB
pc445 0:c5d5930ea5e7 67 write_SPI(0xC000); //write phase reg - 0 for now
pc445 0:c5d5930ea5e7 68 write_SPI(0x2000); //write control reg - disable reset
pc445 0:c5d5930ea5e7 69 }
pc445 0:c5d5930ea5e7 70
pc445 0:c5d5930ea5e7 71 /////////////////////////////////////////////////////////////////////////
pc445 0:c5d5930ea5e7 72 // Main function
pc445 0:c5d5930ea5e7 73 // Comments:include the command line from Matlab
pc445 0:c5d5930ea5e7 74 // Control from COM port
pc445 0:c5d5930ea5e7 75 /////////////////////////////////////////////////////////////////////////
pc445 0:c5d5930ea5e7 76 int main()
pc445 0:c5d5930ea5e7 77 {
pc445 0:c5d5930ea5e7 78 SPI_INITIALIZATION(); // initialized the SPI
pc445 0:c5d5930ea5e7 79 setFreq(100000);
pc445 0:c5d5930ea5e7 80 }