Diff: main.cpp

Revision:

3:3bef1c4e42d4

Parent:

2:0baf535ed8f8

Child:

4:235e50314809

--- a/main.cpp	Mon Sep 22 04:29:44 2014 +0000
+++ b/main.cpp	Mon Sep 22 06:23:35 2014 +0000
@@ -25,7 +25,7 @@
 // check if the input is valid
 bool si_check_valid(const char & input)
 {
-    if ( ( ( int(input) > 57) || ( int(input) < 48) ) && (input != '+') && (input != '-') && (input != '*') && (input != '/') && (input != '=') ) {
+    if ( ( ( int(input) > 57) || ( int(input) < 48) ) && (input != '+') && (input != '-') && (input != '*') && (input != '/') && (input != '^') && (input != '=') ) {
         return FALSE;
     } else {
         return TRUE;
@@ -42,23 +42,23 @@
     }
 }
 
+char c;
+char op = '=';
+char operand [100];
+char buf[10];
+int result =0;
+int result_copy=0;
+int index = 0;
+int ioperand =0;
+bool first = TRUE;
+bool sign_check = TRUE;
+bool neg_operand = FALSE;
+bool error=FALSE;
 
 
-int main()
+// serial interrup callback function
+void callback()
 {
-    char c;
-    char op = '=';
-    char operand [100];
-    char buf[10];
-    int result =0;
-    int index = 0;
-    int ioperand =0;
-    bool first = TRUE;
-    bool sign_check = TRUE;
-    bool neg_operand = FALSE;
-
-    pc.printf("LPC Integer Calculator!\n");
-
     while(1) {
 
         c=pc.getc();  //get serial input
@@ -84,8 +84,8 @@
                 } else {
                     ioperand = char_to_int(operand,index);
                 }
-                neg_operand=FALSE;
-                
+
+
                 if (first) {  //First Operator
                     result = ioperand;
                     first = FALSE;
@@ -99,22 +99,36 @@
                         result = int (result / ioperand);
                     } else if (op == '*') {
                         result = int (result * ioperand);
+                    } else if (op == '^') {
+                        if(!neg_operand) {
+                            result_copy = result;
+                            for(int i = (abs(ioperand) -1); i>0; i--) {
+                                result *=result_copy;
+                            }
+                        } else {
+                            pc.printf("ERROR:Negative exponent");
+                            error = TRUE;
+                        }
                     }
 
                     if (c == '=') { // Operator = has been entered--> Print result and reset calculator
                         for (int j =9; j>=0; j--) {
                             buf[j]='\0';
                         }
-                        sprintf(buf, "%d", result);
-                        pc.printf("%s", buf);
+                        if(!error) {
+                            sprintf(buf, "%d", result);
+                            pc.printf("%s", buf);
+                        }
                         pc.printf("\n\n");
                         pc.printf("Please enter a new operation\n");
                         first = TRUE;
+                        error = FALSE;
                     }
                 }
                 op = c;  // assign the Operator
                 index=0; // reset the operand
                 sign_check = TRUE; // sign check activated
+                neg_operand=FALSE;
             } else {
                 pc.putc(c);
                 if (c=='-') {
@@ -123,11 +137,19 @@
                 } else if (c=='+') {
                     neg_operand=FALSE;
                     sign_check = FALSE;
-                } else { 
-                pc.printf("ERROR:Two consecutive Operators entered");               
+                } else {
+                    pc.printf("ERROR:Two consecutive Operators entered");
+                    error = TRUE;
                 }
             }
         }
     }
 }
 
+int main()
+{
+    pc.attach(&callback,Serial::RxIrq);
+
+    pc.printf("LPC Integer Calculator!\n");
+    while (1) {}
+}
\ No newline at end of file