Diff: main.cpp

Revision:

4:9b7ea5528a5c

Parent:

3:b7df72682b81

Child:

5:e785b9cd58c9

--- a/main.cpp	Wed Apr 01 16:25:32 2020 +0000
+++ b/main.cpp	Tue Apr 07 18:56:28 2020 +0000
@@ -8,7 +8,7 @@
 Username: el18loc
 Student ID Number: 201225242
 Start Date: 06/02/2020
-Last Edited: 12/03/2020
+Last Edited: 07/04/2020
 */
 
 // Includes
@@ -19,7 +19,10 @@
 // Objects
 Gamepad pad;
 N5110 lcd;
-Timer t;
+Ticker down;
+Ticker period;
+
+DigitalOut rca(PTC4);
 
 Serial pc(USBTX, USBRX);
 
@@ -27,29 +30,33 @@
 void startup();
 void squareWave();
 void wavetable();
-void sinspeak();
+//void sinspeak();
+void down_isr();
+void up_isr();
 
 //Arrays for startup
-const int notes[8] = {330,0,330,294,330,247,294,392};
-const int duration[8] = {4,8,4,8,8,4,8,4};
 const char CART[4] = {'C','A','R','T'};
-const char SYNTH[5] = {'S','Y','N','T','H'};
 
 //Global Variables
-volatile unsigned short o[4096];
+volatile double wavtable[4096]; //Wavetable array
+// all times drastically slowed to attempt debugging in teraterm
+float g_period = 0.002;
+float g_unused= g_period*1000000.0f;
+int g_period_us=g_unused;
+volatile uint64_t g_uptime_us = g_period_us/2; // placeholder value
+//isr interrupt flags
+volatile int g_upflag=1;
+volatile int g_downflag=1;
 
 int main()
 {
     printf("RUNNING CODE \n");
-    startup();
-    wavetable();
-    pad.leds_on();
-    sinspeak();
-    pad.leds_off();
-    for (int rep=0; rep<10; rep++) {
-    sinspeak();
-    }
-//  squareWave();
+    startup(); //initialises board and displays start screen
+    wavetable(); //generates wavtable array
+    //pad.leds_on();
+    squareWave(); //generates pulse wave modulated by sin wave
+    //pad.leds_off();
+    //sinspeak();
 }
 
 
@@ -58,19 +65,15 @@
     pad.init(); //initiate Gamepad
     pad.leds_on(); //turn LEDS on to show starting up
     printf("Initialising Pad\n");
-    pad.play_melody(8,notes,duration,108,0); //play startup tune
     lcd.init(); //intitates screen
     lcd.clear();
-    lcd.setContrast(0.4f); //contrast setting
+    lcd.setContrast(0.5); //contrast setting
     lcd.inverseMode(); //puts screen in -ve
-    //positions for CART SYNTH
+    //position for CART
     const int x = 10;
     const int y = 2;
-    const int a = 40;
-    const int b = 4;
     //Prints CART SYNTH to display
     lcd.printString(CART,x,y);
-    lcd.printString(SYNTH,a,b);
     lcd.refresh();
     wait_ms(1800); //timer to allow theme to play out
     lcd.clear();
@@ -81,27 +84,84 @@
 
 void wavetable()
 {
-    int samples= 4096;
-    float sinfl[samples];
-    int sinf[samples];
+    double sin_d[4096];
 
-    pad.leds_on(); //shows computating
+    pad.leds_on(); //shows computating (debug)
     printf("Generating Wavetable \n");
-    wait_ms(500); //shows reaches stage
-
-    float ifl=0.0; //creates fl type incramenter
 
     for (int i=0; i<4096; i++) {
-        sinfl[i] = 65536.0f*sin(2.0f*PI*(ifl/4096.0f));
-        sinf[i] = sinfl[i];
-        o[i]= sinf[i]+32767; //generates wave table in uint
-       // printf("o[i]= %u \n", o[i]); // Used for Debug
-        ifl=i+1.0f;
+        sin_d[i] = 0.5f*sin(2.0f*PI*(i/4096.0f));
+        wavtable[i]= sin_d[i]+0.5; //generates wave table 0<1 in double
+        //printf("wav[i]= %f \n", wavtable[i]); // Used for Debug
     }
     pad.leds_off();
 }
 
 
+void squareWave()
+{
+    printf("Generating SIN PWM \n");
+
+    int i=0; //int based iterator
+    float ifl=0; //float based itterator
+    float f=50; //frequency of sin wave produced
+    period.attach_us(&up_isr,g_period_us); //ticker to write 1 to rca
+    down.attach_us(&down_isr,g_uptime_us); //ticker to write 0 to rca
+    
+    
+    printf("g_period_us: %d \n", g_period_us);
+    printf("sin Frequency: %f \n", f);
+
+    while (1) { //continual loop for pulse production
+        float dutyratio = wavtable[i]; //calcualtes duty ratio of pulse
+        
+        g_uptime_us= dutyratio*g_period_us; //calculates duty ratio in usecs
+        if (g_uptime_us<1) {
+            g_uptime_us=g_period_us/100;
+            } //sets to be value for timebeing to eliminate 0 error
+        //float f=440*(pad.read_pot1()+1); //removed for simplification
+        
+        if (g_upflag==0) {
+            
+            ifl = ifl + (4096*f*g_period); //once rca=1 itterate sin function
+            if (ifl>4096) {
+                ifl= ifl-4096;
+                }
+            i=ifl;
+            
+            g_upflag=1; //reset flag
+            //printf("iterate i: i= %d, ifl= %f \n", i, ifl);
+        }
+        
+        //printf("DR: %f \n",dutyratio);
+        //printf("sleep \n");
+        sleep(); //sleeps till next isr
+    }
+}
+
+void down_isr() //sets rca to 0
+{
+    //printf("downISR \n");
+    if (g_downflag==0) {//stops error trigger
+        rca.write(0);
+        g_downflag=1;
+        g_uptime_us= g_uptime_us+g_period_us; // eliminates it calling if =0
+        //printf("0 \n");//print only in while v. slow freguency
+    }
+}
+
+void up_isr() //sets rca=1
+{
+    //printf("upISR \n");
+    rca.write(1);
+    down.attach_us(&down_isr,g_uptime_us); //timer to set rca=0 after elapsed
+    g_upflag=0; //sets flag to iterate
+    g_downflag=0; //sets flag to allow set to 0
+    //printf("1 \n"); //only in while at v low frequency
+}
+
+
+/*
 void sinspeak ()
 {
     float f1=440.0;
@@ -116,8 +176,8 @@
     while (inc<3000) {
         int inti = i;
         v = o[inti];
-        //printf("OUTPUT: %u \n", v);
-        pad.write_u16(v);
+        printf("OUTPUT: %u \n", v);
+        //pad.write_u16(v);
         wait_us(230); //fs= 4k Ts=250us
 
         i = i + ((4096.0f*f1)/4000.0f); //i+((samples*f)*Ts)
@@ -125,31 +185,9 @@
             i=i-4096.0f;
         }
         else {
-            wait_us(3);
+            wait_us(3); // used to attempt note stabilisation to match other loop
             }
         inc++;
     }
 }
-
-void squareWave()
-{
-    // defines local variables
-    float v = 0.0;
-    float f = 440.0;
-    float p1 = 0;
-    // continual loop for square production
-    while (1) {
-        pad.write_dac(v); //wite out value (1/0)
-        //Statements for switch of out
-        if (v == 0.0f) {
-            v=0.1;
-        } else {
-            v=0.0;
-        }
-        p1 = pad.read_pot1(); //read pot 1 value
-        f = 440 + 440*p1; //convert to freq (A4->A5)
-        float T=1/f; //calc Period of wave
-        wait(T); //timer for switch value (T)
-    }
-
-}
+*/
\ No newline at end of file