INPUT SWITCH Reading

simple example to show how to read input button attached to PortA. Led on when button pressed

Author: abdul-rehman-2050

SWITCH_READ_EX01.c

@@ -0,0 +1,47 @@
+#include <iostm8s103.h>
+
+  #define SW1	1
+	#define SW_DDR PA_DDR
+	#define SW_CR1 PA_CR1
+	#define SW_CR2 PA_CR2
+	#define SW_IDR PA_IDR
+  
+  
+  #define SW1_HIGH ((SW_IDR)&(1<<SW1))
+  
+  
+  #define LED_HIGH	PB_ODR |= (1<<5)    //ON BOARD LED 
+	#define LED_LOW		PB_ODR &= ~(1<<5)
+	
+  
+  void delay(long x);
+  
+main()
+{
+	unsigned int d;
+	
+	CLR_BIT(SW_DDR,SW1);	//SET SW1 AS INPUT
+	SET_BIT(SW_CR1,SW1);	//input pullup without interrupt
+  PB_DDR = 255;		//PORTB AS OUTPUT
+  PB_CR1 = 255;
+  while (1){
+		int cnt = 0;
+		if(!SW1_HIGH){
+			LED_HIGH;   //LED OFF
+			do{
+				delay(10);
+			}while(!SW1_HIGH);
+			LED_LOW;  //LED ON 
+		}
+		delay(100);
+	}
+   
+}
+  
+  
+  void delay(long x){
+	char d=0;
+	for(;x>0;x--)
+		for (d = 0; d < 10; d++); //Delay ~ 1 second
+	
+}