Diff: main.cpp

Revision:

4:b242f4206894

Parent:

3:19bb7c30c354

--- a/main.cpp	Mon Jul 23 17:47:22 2018 +0000
+++ b/main.cpp	Sun Aug 19 01:07:58 2018 +0000
@@ -1,5 +1,5 @@
 /*
-   Nucleo F767 DCO
+   Nucleo F767 DCO Test01
    2018.07.22
 
 */
@@ -10,20 +10,22 @@
 
 #define PIN_CHECK   (1)
 #define UART_TRACE  (0)
-#define TITLE_STR1  ("Nucleo F767 DCO")
-#define TITLE_STR2  ("20180724")
+#define TITLE_STR1  ("Nucleo F767 DCO Test01")
+#define TITLE_STR2  ("20180819")
+
 
 // Pin Assign
 AnalogOut Dac1(PA_4);
 AnalogOut Dac2(PA_5);
 
 #if (PIN_CHECK)
-DigitalOut CheckPin(D4);
+DigitalOut CheckPin1(D4);
+DigitalOut CheckPin2(D5);
 #endif
 
 // Parameter
-double drate = 440.0;         // initial output rate (Hz)
-const double refclk = 200000;  // Hz
+double drate = 1000.0;         // initial output rate (Hz)
+const double refclk = 100000;  // 100kHz
 
 // Interruput
 Ticker ticker;
@@ -41,8 +43,9 @@
 //   val: 0 .. 4095
 void InternalDacWrite(int ch, uint16_t val)
 {
-    // avoid distortion of built-in DAC
-    uint16_t v = ((val + 1024) << 3);
+    //uint16_t v = val << 4;
+    // avoid distortion of the built-in DAC
+    uint16_t v = (val + 256) * 14;
     
     switch(ch) {
     case 1:
@@ -57,17 +60,17 @@
 void update()
 {
 #if (PIN_CHECK)
-    CheckPin.write(1);
+    CheckPin1.write(1);
 #endif
 
     phaccu = phaccu + tword_m;
     uint16_t idx = phaccu >> 17;  // use upper 15 bits
     
     InternalDacWrite(1, sin_12bit_32k[idx]);
-    InternalDacWrite(2, sin_12bit_32k[idx]);
+    //InternalDacWrite(2, sin_12bit_32k[idx]);
 
 #if (PIN_CHECK)
-    CheckPin.write(0);
+    CheckPin1.write(0);
 #endif
 }
 
@@ -79,10 +82,17 @@
 {
     tword_m = pow(2.0, 32) * drate / refclk;  // calculate DDS tuning word;
     
+    // 1.0s / 1.0us = 1000000.0
     float interruptPeriodUs = 1000000.0 / refclk; 
     ticker.attach_us(&update, interruptPeriodUs);
     
     while (1) {
+#if (PIN_CHECK)
+    CheckPin2.write(1);
+    wait_us(1);
+    CheckPin2.write(0);
+    wait_us(1);
+#endif
     }
 }