Diff: main.cpp

Revision:

0:c5d5930ea5e7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Nov 26 18:21:15 2014 +0000
@@ -0,0 +1,80 @@
+/////////////////////////////////////////////////////////////////////////
+// AD9833 control code
+// Create by Po-Cheng Chen 07-04-2014
+// Version 0.1
+/////////////////////////////////////////////////////////////////////////
+
+#include "mbed.h"
+#include "SPI.h"
+#include "DigitalOut.h"
+
+SPI AD9833_SPI(p5, p6, p7); //mosi, miso, sclk --> don't need MISO
+DigitalOut fSync(p8); //use p8 as FSync data pin (same as chip select)
+
+/////////////////////////////////////////////////////////////////////////
+// SPI initialization
+/////////////////////////////////////////////////////////////////////////
+void SPI_INITIALIZATION()
+{
+    //Setup the spi for 16 bit data, with 25MHz clock rate, mode 2
+    // Note: mBed is MSB first SPI protocol
+    AD9833_SPI.format(16,2);
+    AD9833_SPI.frequency(25000000);
+    fSync = 1;
+    wait_ms(10);
+}
+/////////////////////////////////////////////////////////////////////////
+// SPI writing
+/////////////////////////////////////////////////////////////////////////
+void write_SPI(short dat)
+{
+    fSync = 0;
+    AD9833_SPI.write(dat);
+    fSync = 1;
+}
+/////////////////////////////////////////////////////////////////////////
+// Set desired frequency
+// Comments:Calculate the desired frequency accrodingly
+//          Do it in Matlab or mBed?
+/////////////////////////////////////////////////////////////////////////
+void setFreq(long FREQ)
+{
+    int freq_MSB;   //define freq MSB reg value
+    int freq_LSB;   //define freq LSB reg value
+    
+    long freq_cal;  //define freq calculated value
+    float freq_val = 0.00000000;    //define ferq calculate tempotary value
+    
+    //calculate the frqe reg value
+    //((desired frequency)/(reference frequency)) x 0x10000000.
+    freq_val = (((float)(frequency))/25000000);
+    freq_cal = freq_val*0x10000000;
+    
+    freq_MSB = (int)((freq_cal & 0xFFFC000)>>14); // shift 14 bits
+    freq_LSB = (int)(freq_cal & 0x3FFF);
+    
+    freq_MSB = freq_MSB | 0x4000;  //assign freq reg address
+    freq_LSB = freq_LSB | 0x4000;
+    ///////////////////////////////////////////////////////////////////////////////////    
+    //print the data from the serial port to verifiy the function
+    printf("freq_LSB 0x%x\n\r", freq_LSB);
+    //print the data from the serial port to verifiy the function
+    printf("freq_MSB 0x%x\n\r", freq_MSB);
+    ///////////////////////////////////////////////////////////////////////////////////
+    write_SPI(0x2100);      //write control reg - apply reset
+    write_SPI(freq_LSB);    //write freq reg - LSB
+    write_SPI(freq_MSB);    //write freq reg - MSB
+    write_SPI(0xC000);      //write phase reg - 0 for now
+    write_SPI(0x2000);      //write control reg - disable reset
+}
+
+/////////////////////////////////////////////////////////////////////////
+// Main function
+// Comments:include the command line from Matlab
+//          Control from COM port
+/////////////////////////////////////////////////////////////////////////
+int main()
+{
+    SPI_INITIALIZATION(); // initialized the SPI
+    setFreq(100000);
+}
\ No newline at end of file