Diff: main.cpp

Revision:

0:0981765e0a06

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sat Mar 03 02:53:19 2018 +0000
@@ -0,0 +1,201 @@
+
+/* 
+ * ENGR E 210 - CYBER PHYSICAL SYSTEMS (DIGITAL SYSTEMS)
+ * LAB 3 - ANALOG FILTERS AND OSCILLOSCOPE
+ * CODE BY KRISH HEMANT MHATRE AND ETHAN ZHANG
+ */
+#include "mbed.h"
+#include <string.h>
+
+#if !DEVICE_ANALOGOUT
+#error You cannot use this example as the AnalogOut is not supported on this device.
+#else
+AnalogOut my_output(PA_4);
+#endif
+
+#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)
+
+// Configuration for sinewave output
+#define BUFFER_SIZE (360)
+uint16_t buffer[BUFFER_SIZE];
+
+Serial pc(USBTX, USBRX);
+DigitalOut led1(LED1);
+DigitalIn button(PC_13);
+
+void Led(int a)
+{
+    led1 = a;
+}
+
+void Blink(int n)
+{
+    int i = 0;
+    for(i=0; i<n; i++)
+    {
+        led1 = 1;
+        wait(0.5);
+        led1= 0;
+        wait(0.5);
+    }
+}
+
+
+void Button()
+{
+    if(button.read() == 1)
+    {
+        pc.printf("RELEASED\n\r");
+    }
+    else
+    {
+        pc.printf("PRESSED\n\r");
+    }
+}
+
+void calculate_sinewave(float amp){
+  for (int i = 0; i < BUFFER_SIZE; i++) {
+     double rads = (PI * i)/180.0; // Convert degree in radian
+     buffer[i] = (uint16_t)(amp * (RANGE * (cos(rads + PHASE))) + OFFSET);
+  }
+}
+
+int main() 
+{
+    pc.printf("Nucleo is running\n\r");
+    pc.printf("cps%\n\r");
+    int size = 32;
+    char str[size];
+    int i = 0;
+    while(1)
+    {
+        str[i] = pc.getc();
+        pc.putc(str[i]);
+        
+        if (i >= size)
+        {
+            pc.printf("OVER BUFFER\n\r");
+            i = 0;
+            for(int j = 0; j < size; j++)
+            {
+                str[j] = 0;
+            }
+            pc.printf("cps%\n\r");
+        }
+        if(str[i] == 13)
+        {
+            pc.printf("\n\rOK\n\r");
+            str[i] = '\0';
+            pc.printf("Command Recieved: %s\n\r", str);
+            char s[5];
+            sscanf(str, "%s", s);
+            if(strcmp(str, "BUTTON") == 0)
+            {
+                Button();
+                pc.printf("Button checked.\n\r");
+            }
+            else if(strcmp("LED ON", str) == 0)
+            {
+                Led(1);
+                pc.printf("LED is on\n\r");
+            }
+            else if(strcmp("LED OFF", str) == 0)
+            {
+                Led(0);
+                pc.printf("LED is off\n\r");
+            }
+            else if(strcmp(s, "BLINK") == 0)
+            {
+                pc.printf("Reading a blink\n\r");
+                char *a = strtok(str, " ");
+                a = strtok(NULL, " ");
+                pc.printf("Start blink\n\r");
+                int n;
+                sscanf(a, " %d", &n);
+                if(n>=1 && n<=10)
+                {
+                   Blink(n);
+                   pc.printf("Blink complete\n\r");
+                }
+                else
+                {
+                    pc.printf("ERROR: Blink cycle should be between 1 and 10\n\r");
+                }
+            }
+            else if(strncmp(str, "DC", 2) == 0)
+            {
+                   pc.printf("Reading DC\n\r");
+                   char *s1 = strtok(str, " ");
+                   s1 = strtok(NULL, " ");
+                   float volt;
+                   sscanf(s1, " %f", &volt);
+                   
+                   if((volt < (float)0.5) || (volt > (float)3.0))
+                   {
+                       pc.printf("Voltage out of range\n\r");    
+                   }
+                   else 
+                   {  
+                       float adjust = 19720;
+                       
+                       pc.printf("Voltage is %f\n\r", volt);
+                       my_output.write_u16(volt*adjust);
+                       pc.printf("Voltage changed\n\r");
+                   }
+            }
+            else if(strncmp(str, "SINE", 4) == 0)
+            {
+                   float x, amp, freq;
+                   char tmp[5];
+
+                   sscanf(str, "%s %f %f\n", tmp, &amp, &freq);
+                   pc.printf("Reading data\n\r");
+                   if((amp < (float)0.5) || (amp > (float)3.0) || (freq < (float)100) || (freq > (float)500))
+                   {
+                       pc.printf("Data out of range\n\r");    
+                   }
+                   else 
+                   {  
+                       pc.printf("Generating sine wave of amplitude %fV and frequency %fHz\n\r", amp, freq);
+                       x = (float)((float)amp/(float)3.3); //3.3V is the given voltage
+                       calculate_sinewave(x);
+                       while(1) 
+                       {      
+                          for (int i = 0; i < BUFFER_SIZE; i++) 
+                          {
+                             my_output.write_u16(buffer[i]);
+                             float delay;
+                             if(freq <= 200)
+                             {
+                                delay = (float)((float)((float)4000-(float)((float)5*freq))/(float)(freq*(float)(PI/2)));
+                             }
+                             else
+                             {
+                                delay = (float)((float)((float)5000-(float)((float)12*(float)freq))/(float)(freq));   
+                             }
+                             delay = ((float)(delay/1000000)); //converting microseconds to seconds
+                             wait(delay);
+                          }
+                       }
+                   }
+            }
+            else
+            {
+                pc.printf("ERR\n\r");
+            }
+            i = 0;
+            for(int j = 0; j < size; j++)
+            {
+                str[j] = '\0';
+            }
+            pc.printf("cps%\n\r");
+        }
+        i++;
+    }
+}
+
+