Diff: main.cpp

Revision:

0:b12e0784b4b4

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Oct 21 15:58:36 2016 +0000
@@ -0,0 +1,142 @@
+#include "mbed.h"
+
+DigitalOut led_red(LED_RED);
+DigitalOut led_green(LED_GREEN);
+DigitalOut led_blue(LED_BLUE);
+DigitalIn sw2(SW2);
+DigitalIn sw3(SW3);
+Serial pc(USBTX, USBRX);
+AnalogOut my_output(DAC0_OUT);
+
+char newFreq[3];
+int Freq = 60;
+//int bufferSize = 0;
+
+#define PI        (3.141592653589793238462)
+#define AMPLITUDE (1.0)    // x * 3.3V
+#define PHASE     (PI * 1) // 2*pi is one period
+#define RANGE     (0x7FFF)
+#define OFFSET    (0x7FFF)
+#define STEP_US   (49)
+#define FREQ_HZ   (60)
+#define STEP      (0.00005)
+#define BUFFER_SIZE ( (int) ( 1 / ( FREQ_HZ * STEP )))
+
+int bufferSize = ( (int) ( 1 / ( Freq * STEP )));
+int sw2_data = 0;
+
+void calculate_sinewave(void);
+void calculate_squarewave(void);
+void calculate_triwave(void);
+void check_sw2(void)
+{
+    if (sw2 == 0) {
+        //sw2_data++;
+        //pc.printf("SW2 button pressed. \n");
+        if (sw2_data == 0) {
+            led_green = 1;
+            led_blue = 0;
+            led_red = 1;
+            calculate_triwave();
+            pc.printf("TRIANGLE - Blue\n");
+            sw2_data = 1;
+            }
+        else if (sw2_data == 1) {
+            led_green = 1;
+            led_blue = 1;
+            led_red = 0;
+            calculate_squarewave();
+            pc.printf("SQUARE - Red\n");
+            sw2_data = 2;
+            }        
+        else if (sw2_data == 2) {
+            led_green = 0;
+            led_blue = 1;
+            led_red = 1;
+            calculate_sinewave();
+            pc.printf("SINE - Green\n");
+            sw2_data = 0;
+            }
+        wait_us(1000000);
+    }
+}
+
+void check_sw3(void)
+{
+    if (sw3 == 0) {
+        //pc.printf("SW3 button pressed. \n");
+        led_green = 1;
+        led_red = 1;
+        led_blue = 0;
+        pc.printf("Enter a 3 digit frequency. Start typing. \n");
+        for (uint32_t i = 0; i < 3; i++) {
+            newFreq[i] = pc.putc(pc.getc());
+        }
+        pc.putc(13); /* CR */
+        pc.putc(10); /* LF */
+//        pc.printf("Freq: %s\n",newFreq);
+        sscanf(newFreq, "%d", &Freq);
+        pc.printf("Freq: %d Hz\n",Freq);
+        bufferSize = ( (int) ( 1 / ( Freq * STEP )));
+        pc.printf("Buffer: %d\n",bufferSize);
+        uint16_t *buffer = new uint16_t[bufferSize];
+        calculate_sinewave();
+        sw2_data = 0;
+    }
+}
+
+uint16_t *buffer = new uint16_t[bufferSize];
+
+int main() {
+    led_green = 1;
+    led_red = 1;
+    led_blue = 0;
+    pc.baud(115200);
+    pc.printf("\nNXP FRDM-K22F board.\n");
+    pc.printf("Frequency Generator\n");
+    pc.printf("Freq: %d Hz\n",FREQ_HZ);
+    pc.printf("Buffer: %d\n",bufferSize);
+    pc.printf("\n");
+    calculate_sinewave();
+
+    while(1) {              
+        // sinewave output
+        for (int i = 0; i < bufferSize; i++) {
+            my_output.write_u16(buffer[i]);
+            wait_us(STEP_US);
+        }
+        check_sw3();
+        check_sw2();
+    }
+}
+
+// Create the sinewave buffer
+void calculate_sinewave(void){
+  for (int i = 0; i < bufferSize; i++) {
+     double rads = (PI * i)/(bufferSize / 2); // Convert degree in radian
+     buffer[i] = (uint16_t)(AMPLITUDE * (RANGE * (cos(rads + PHASE))) + OFFSET);
+  }
+}
+
+// Create the squarewave buffer
+void calculate_squarewave(void){
+  for (int i = 0; i < (bufferSize / 2); i++) {
+     buffer[i] = (uint16_t)(AMPLITUDE * (RANGE * (1)) + OFFSET);
+  }
+  for (int i = (bufferSize / 2); i < (bufferSize); i++) {
+       buffer[i] = 0; //(uint16_t)(AMPLITUDE * (RANGE * (0.0)) + OFFSET);
+  }
+}
+
+// Create the trianglewave buffer
+void calculate_triwave(void){
+  for (int i = 0; i < (bufferSize/2); i++) {
+     double triPlus = (double) i / (bufferSize/2);
+     double triMinus = (double) (1.0 - (triPlus));
+     buffer[i] = (uint16_t)(AMPLITUDE * ((RANGE*2) * (triPlus)));
+     buffer[(i + ((bufferSize / 2)))] = (uint16_t)(AMPLITUDE * ((RANGE*2) * (triMinus)));
+     //pc.printf("Buffer: %E\n",triPlus);
+     //pc.printf("Buffer: %E\n",triMinus);
+  }
+  buffer[bufferSize - 1] = 0;
+}
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