Revision 1:bb422b8b8285, committed 2020-08-08

Comitter:

liammchale

Date:

Sat Aug 08 09:36:15 2020 +0000

Parent:

0:7de212f91ff4

Commit message:

saved with comments attached, previously not included

Changed in this revision

--- a/main.cpp	Sat Aug 08 09:04:49 2020 +0000
+++ b/main.cpp	Sat Aug 08 09:36:15 2020 +0000
@@ -1,46 +1,52 @@
+//embedded systems lab question 1
+//Write a program using interrupts on digital pins 12-16 (Joystick on Application board).
+// Use printf to print to terminal the direction the jostick is moved.
+// pin defined for Joystick Inputs and LED outputs as per Appliciation board.
+//improve the performace of the program by using a debounce function
+
 #include "mbed.h" //preprocessor demands
 
 Serial pc(USBTX,USBRX);//serial communication to PC via the tx,rx
 
-InterruptIn down(p12);//global declaration
-InterruptIn left(p13);//global declaration
-InterruptIn center(p14);//global declaration
-InterruptIn up(p15);//global declaration
-InterruptIn right(p16);//global declaration
+InterruptIn down(p12);//down
+InterruptIn left(p13);//left
+InterruptIn center(p14);//center
+InterruptIn up(p15);//up
+InterruptIn right(p16);//right
 
-float debounce(0.5);
+float debounce(0.5);//new mechancial bounce on the switch contacts
 
 
 void Down(){
-    pc.printf("DOWN\r\n");
-    wait (debounce);
+    pc.printf("DOWN\r\n");//print new line, return to start of new line
+    wait (debounce);//waits the value of half a second set in above float
     }
 void Left(){
-    pc.printf("LEFT\r\n");
-    wait (debounce);
+    pc.printf("LEFT\r\n");//print new line, return to start of new line
+    wait (debounce);//waits the value of half a second set in above float
     }
 void Center(){
-    pc.printf("CENTER\r\n");
-    wait (debounce);
+    pc.printf("CENTER\r\n");//print new line, return to start of new line
+    wait (debounce);//waits the value of half a second set in above float
     }
 void Up(){
-    pc.printf("UP\r\n");
-    wait (debounce);
+    pc.printf("UP\r\n");//print new line, return to start of new line
+    wait (debounce);//waits the value of half a second set in above float
     }
 void Right(){
-    pc.printf("RIGHT\r\n");
-    wait (debounce);
+    pc.printf("RIGHT\r\n");//print new line, return to start of new line
+    wait (debounce);//waits the value of half a second set in above float
     }
     
-int main(){
+int main(){//main program
     while (1){
         wait(5);
-        down.rise(&Down);
-        left.rise(&Left);
-        center.rise(&Center);
-        up.rise(&Up);
-        right.rise(&Right);
-        down.rise(&Down);
+        down.rise(&Down);//interrupt the rising edge (0>1)
+        left.rise(&Left);//interrupt the rising edge (0>1)
+        center.rise(&Center);//interrupt the rising edge (0>1)
+        up.rise(&Up);//interrupt the rising edge (0>1)
+        right.rise(&Right);//interrupt the rising edge (0>1)
+        down.rise(&Down);//interrupt the rising edge (0>1)
         }
 }