Diff: main.cpp

Revision:

0:15b3f9279b88

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Jul 07 02:03:22 2014 +0000
@@ -0,0 +1,166 @@
+/////////////////////////////////////////////////////////////////////////
+// AD9833 control code
+// Create by Po-Cheng Chen 07-04-2014
+// Version 0.2 (MATLAB)
+/////////////////////////////////////////////////////////////////////////
+
+#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)
+
+Serial pc(USBTX, USBRX);    //define serial USB port
+DigitalOut myled1(LED1), myled2(LED2), myled3(LED3), myled4(LED4); //define LEDs
+
+/////////////////////////////////////////////////////////////////////////
+// ASCII to Interger function
+/////////////////////////////////////////////////////////////////////////
+unsigned int ascii2int(char c)
+{
+    unsigned int i;
+    i = 0;
+    switch(c) {
+        case 0x20:
+            i = 0;
+            break;
+        case '0' :
+            i = 0;
+            break;
+        case '1' :
+            i = 1;
+            break;
+        case '2' :
+            i = 2;
+            break;
+        case '3' :
+            i = 3;
+            break;
+        case '4' :
+            i = 4;
+            break;
+        case '5' :
+            i = 5;
+            break;
+        case '6' :
+            i = 6;
+            break;
+        case '7' :
+            i = 7;
+            break;
+        case '8' :
+            i = 8;
+            break;
+        case '9' :
+            i = 9;
+            break;
+        default:
+            i = 0;
+            break;
+    }
+    return i;
+}
+/////////////////////////////////////////////////////////////////////////
+// 8 digit function
+/////////////////////////////////////////////////////////////////////////
+unsigned int digit8(char c7, char c6, char c5, char c4,
+                    char c3, char c2, char c1, char c0)
+{
+    unsigned int k7 = 10000000*ascii2int(c7);
+    unsigned int k6 = 1000000*ascii2int(c6);
+    unsigned int k5 = 100000*ascii2int(c5);
+    unsigned int k4 = 10000*ascii2int(c4);
+    unsigned int k3 = 1000*ascii2int(c3);
+    unsigned int k2 = 100*ascii2int(c2);
+    unsigned int k1 = 10*ascii2int(c1);
+    unsigned int k0 = ascii2int(c0);
+    unsigned int k = k7 + k6 + k5 + k4 + k3 + k2 + k1 + k0;
+    return k;
+}
+/////////////////////////////////////////////////////////////////////////
+// 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;
+}
+/////////////////////////////////////////////////////////////////////////
+// Calculate desired frequency
+/////////////////////////////////////////////////////////////////////////
+long calFreq(long freq)
+{
+    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)(freq))/25000000);
+    freq_cal = freq_val*0x10000000;
+    return freq_cal;
+}
+/////////////////////////////////////////////////////////////////////////
+// Set frequency register
+/////////////////////////////////////////////////////////////////////////
+void setFreq(long frequency)
+{   
+    int freq_MSB;   //define freq MSB reg value
+    int freq_LSB;   //define freq LSB reg value
+    
+    long freq_cal = calFreq(frequency); //calculate the frequency register
+    
+    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);
+    //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()
+{
+    char buf[128];     // assign buffer for the command from PC
+    SPI_INITIALIZATION(); // initialized the SPI
+    while(true) {
+        if (pc.readable()) {
+            //WAV AAAA BBBB CCCC DDDD EEEE FFFF GGGG HHHH END \n \0
+            //A, B, C, D ,E, F, G, H are frequency numbers
+            //need 3 + (32) + 3 + 1 + 1 = 40
+            pc.gets(buf, 16);
+            if ((buf[0] == 'W')&&(buf[1] == 'A')&&(buf[2] == 'V')&&(buf[11] == 'E')&&(buf[12] == 'N')&&(buf[13] == 'D')) {
+                myled1 = !myled1;
+                int freq_pc = digit8(buf[3], buf[4], buf[5], buf[6], buf[7], buf[8], buf[9], buf[10]);
+                setFreq(freq_pc);
+                
+            } // end of if( buffer read)
+        } // end of if(pc.readable())        
+    }// end of while()
+} // end of main()
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