Final version of TuningFork.c

Labware/Lab12_TuningFork/TuningFork.c

-// TuningFork.c Lab 12
-// Runs on LM4F120/TM4C123
-// Use SysTick interrupts to create a squarewave at 440Hz.  
-// There is a positive logic switch connected to PA3, PB3, or PE3.
-// There is an output on PA2, PB2, or PE2. The output is 
-//   connected to headphones through a 1k resistor.
-// The volume-limiting resistor can be any value from 680 to 2000 ohms
-// The tone is initially off, when the switch goes from
-// not touched to touched, the tone toggles on/off.
-//                   |---------|               |---------|     
-// Switch   ---------|         |---------------|         |------
-//
-//                    |-| |-| |-| |-| |-| |-| |-|
-// Tone     ----------| |-| |-| |-| |-| |-| |-| |---------------
-//
-// Daniel Valvano, Jonathan Valvano
-// January 15, 2016
-
-/* This example accompanies the book
-   "Embedded Systems: Introduction to ARM Cortex M Microcontrollers",
-   ISBN: 978-1469998749, Jonathan Valvano, copyright (c) 2015
-
- Copyright 2016 by Jonathan W. Valvano, valvano@mail.utexas.edu
-    You may use, edit, run or distribute this file
-    as long as the above copyright notice remains
- THIS SOFTWARE IS PROVIDED "AS IS".  NO WARRANTIES, WHETHER EXPRESS, IMPLIED
- OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
- MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
- VALVANO SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL,
- OR CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
- For more information about my classes, my research, and my books, see
- http://users.ece.utexas.edu/~valvano/
- */
-
-
-#include "TExaS.h"
-#include "..//tm4c123gh6pm.h"
-
-
-// basic functions defined at end of startup.s
-void DisableInterrupts(void); // Disable interrupts
-void EnableInterrupts(void);  // Enable interrupts
-void WaitForInterrupt(void);  // low power mode
-
-unsigned long flag = 0;
-unsigned long temp = 0;
-unsigned long lastState = 0;
-
-// input from PA3, output from PA2, SysTick interrupts
-void Sound_Init(void){ 
-  unsigned long delay;
-  SYSCTL_RCGC2_R |= 0x00000001; // activate port A
-  delay = SYSCTL_RCGC2_R;
-  GPIO_PORTA_AMSEL_R &= ~0x20;      // no analog
-  GPIO_PORTA_PCTL_R &= ~0x000F0000; // regular function
-  GPIO_PORTA_DIR_R |= 0x20;     // make PA5 out
-  GPIO_PORTA_DR8R_R |= 0x20;    // can drive up to 8mA out
-  GPIO_PORTA_AFSEL_R &= ~0x20;  // disable alt funct on PA5
-  GPIO_PORTA_DEN_R |= 0x20;     // enable digital I/O on PA5
-  NVIC_ST_CTRL_R = 0;           // disable SysTick during setup
-  NVIC_ST_RELOAD_R = 39999;     // reload value for 500us (assuming 80MHz)
-  NVIC_ST_CURRENT_R = 0;        // any write to current clears it
-  NVIC_SYS_PRI3_R = NVIC_SYS_PRI3_R&0x00FFFFFF; // priority 0               
-  NVIC_ST_CTRL_R = 0x00000007;  // enable with core clock and interrupts
-  EnableInterrupts();
-}
-
-// called at 880 Hz
-void SysTick_Handler(void){
-  if(flag==1)
-		GPIO_PORTA_DATA_R ^= 0x04;
-	else GPIO_PORTA_DATA_R &= ~0x04;
-}
-
-int main(void){// activate grader and set system clock to 80 MHz
-  TExaS_Init(SW_PIN_PA3, HEADPHONE_PIN_PA2,ScopeOn); 
-  Sound_Init();         
-  EnableInterrupts();   // enable after all initialization are done
-  while(1){
-    // main program is free to perform other tasks
-    // do not use WaitForInterrupt() here, it may cause the TExaS to crash
-    temp = GPIO_PORTA_DATA_R & 0x08;
-		if(temp == 0x08 && lastState == 0x00)
-		{
-			flag ^= 1;
-		}
-		lastState = temp;
-  }
-}
+// TuningFork.c Lab 12
+// Runs on LM4F120/TM4C123
+// Use SysTick interrupts to create a squarewave at 440Hz.  
+// There is a positive logic switch connected to PA3, PB3, or PE3.
+// There is an output on PA2, PB2, or PE2. The output is 
+//   connected to headphones through a 1k resistor.
+// The volume-limiting resistor can be any value from 680 to 2000 ohms
+// The tone is initially off, when the switch goes from
+// not touched to touched, the tone toggles on/off.
+//                   |---------|               |---------|     
+// Switch   ---------|         |---------------|         |------
+//
+//                    |-| |-| |-| |-| |-| |-| |-|
+// Tone     ----------| |-| |-| |-| |-| |-| |-| |---------------
+//
+// Daniel Valvano, Jonathan Valvano
+// January 15, 2016
+
+/* This example accompanies the book
+   "Embedded Systems: Introduction to ARM Cortex M Microcontrollers",
+   ISBN: 978-1469998749, Jonathan Valvano, copyright (c) 2015
+
+ Copyright 2016 by Jonathan W. Valvano, valvano@mail.utexas.edu
+    You may use, edit, run or distribute this file
+    as long as the above copyright notice remains
+ THIS SOFTWARE IS PROVIDED "AS IS".  NO WARRANTIES, WHETHER EXPRESS, IMPLIED
+ OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
+ MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
+ VALVANO SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL,
+ OR CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
+ For more information about my classes, my research, and my books, see
+ http://users.ece.utexas.edu/~valvano/
+ */
+
+
+#include "TExaS.h"
+#include "..//tm4c123gh6pm.h"
+
+
+// basic functions defined at end of startup.s
+void DisableInterrupts(void); // Disable interrupts
+void EnableInterrupts(void);  // Enable interrupts
+void WaitForInterrupt(void);  // low power mode
+
+unsigned long Switch = 0;
+unsigned char switchPressedLastTime = 0;
+unsigned char toggle = 0;
+
+// input from PA3, output from PA2, SysTick interrupts
+void Sound_Init(void){ 
+	unsigned long volatile delay;
+	SYSCTL_RCGC2_R |= 0x01;
+	delay = SYSCTL_RCGC2_R;
+	GPIO_PORTA_DEN_R &= ~0x08;
+	GPIO_PORTA_DIR_R &= ~0x08; // MAKE PA2 A OUTPUT
+	GPIO_PORTA_DIR_R |= 0x04; // MAKE PA3 A INPUT
+	GPIO_PORTA_AFSEL_R &= ~0x08; //DIASBLE ALT FUNCTION ON PA2 AND PA3
+	GPIO_PORTA_AFSEL_R &= ~0x04;
+	GPIO_PORTA_DEN_R |= 0x0C; // ENABLE DIGITAL I/O ON PA2 AND PA3
+	GPIO_PORTA_AMSEL_R &= ~0x08; /// DISABLE ANALOG FUNCTIONALITY OF PA
+	GPIO_PORTA_AMSEL_R &= ~0x04;
+	GPIO_PORTA_PCTL_R &= ~0x0000FF00;
+	NVIC_ST_CTRL_R = 0; // disable SysTick during setup
+	NVIC_ST_RELOAD_R = 90908; // reload value
+	NVIC_ST_CURRENT_R = 0; // any write to current clears it
+	NVIC_SYS_PRI3_R = (NVIC_SYS_PRI3_R&0x00FFFFFF)|0x40000000;
+	NVIC_ST_CTRL_R = 0x07;
+	EnableInterrupts();
+}
+
+// called at 880 Hz
+void SysTick_Handler(void){
+		if (toggle) {
+			GPIO_PORTA_DATA_R ^= 0x04;
+		}
+		else {
+			GPIO_PORTA_DATA_R &= ~0x04;
+		}
+}
+
+int main(void){// activate grader and set system clock to 80 MHz
+	unsigned char flag = 0;
+	
+  TExaS_Init(SW_PIN_PA3, HEADPHONE_PIN_PA2,ScopeOn); 
+  Sound_Init();
+	Switch = (GPIO_PORTA_DATA_R &0x08);
+  EnableInterrupts();   // enable after all initialization are done
+
+  while(1){
+		// main program is free to perform other tasks
+    // do not use WaitForInterrupt() here, it may cause the TExaS to crash
+
+		while (Switch == 0x08 && flag ==0) {
+			Switch = (GPIO_PORTA_DATA_R &0x08);
+			GPIO_PORTA_DATA_R = 0x00;  
+			toggle = 0 ;
+		}
+		while (Switch == 0x00 && flag == 0) {
+			Switch = (GPIO_PORTA_DATA_R &0x08);
+			toggle = 0 ;
+		}
+		
+		flag = 1;
+		while (Switch == 0x08 && flag == 1) {
+			Switch = (GPIO_PORTA_DATA_R &0x08);
+			toggle = 1; // Loop till switch pressed off
+		}
+
+		while (Switch == 0x00 && flag == 1){
+			Switch = (GPIO_PORTA_DATA_R &0x08);
+			toggle = 1; // Sound
+		}
+
+		flag = 0;
+	}
+}