Diff: main.cpp

Revision:

0:c19d2c6de515

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Jul 13 20:05:26 2017 +0000
@@ -0,0 +1,106 @@
+#include "mbed.h"
+void setcolhigh(void);
+void setcol1(void);
+void setcol2(void);
+void setcol3(void);
+char key_pressed(void);
+
+//Set up the pins for the keypad
+DigitalOut col1     (PTA16);    // pin 3 on keypad
+DigitalOut col2     (PTE31);    // pin 1 on keypad
+DigitalOut col3     (PTC16);    // pin 5 on keypad
+
+DigitalIn row1      (PTA17);    // pin 2 on keypad
+DigitalIn row2      (PTC12);    // pin 7 on keypad
+DigitalIn row3      (PTC13);    // pin 6 on keypad
+DigitalIn row4      (PTC17);    // pin 4 on keypard
+//Set up the serial communication link
+Serial pc(USBTX, USBRX); // tx, rx
+
+
+
+int main()
+{
+    char my_char;
+    while(1) //infinate loop
+    {
+       my_char = key_pressed(); //Read the value of the key pressed
+       if (my_char !='N')
+       pc.printf("key pressed is %c\n\r",my_char);//print out the key pressed over the serial link
+        wait(0.2);
+    }
+}
+
+char key_pressed(void)
+{
+    char result ='N'; 
+    setcolhigh();
+    wait(0.2);
+    //check col 0
+    setcol1();
+    wait(0.2);
+    if (row1==0)
+        result = '1';
+    if (row2 ==0)
+        result = '4';
+    if (row3 ==0)
+        result ='7';
+    if (row4 ==0)
+        result = '*';
+        
+    //check col 1
+    setcol2();
+    wait(0.2);
+    if (row1==0)
+        result = '2';
+    if (row2 ==0)
+        result = '5';
+    if (row3 ==0)
+        result ='8';
+    if (row4 ==0)
+        result = '0';
+    
+    //check col 2
+    setcol3();
+    wait(0.2);
+    if (row1==0)
+        result = '3';
+    if (row2 ==0)
+        result = '6';
+    if (row3 ==0)
+        result ='9';
+    if (row4 ==0)
+        result = '?';
+    return result;
+}
+
+void setcolhigh()
+{
+    //Set all the columns high
+
+    col1 = 1;
+    col2 = 1;
+    col3 = 1;
+
+}
+void setcol1()
+{
+    //Set column 1 low
+    col1 = 0;
+    col2 = 1;
+    col3 = 1;
+}
+void setcol2()
+{
+    //Set column 2 low
+    col1 = 1;
+    col2 = 0;
+    col3 = 1;
+}
+void setcol3()
+{
+    //set column 3 low
+    col1 = 1;
+    col2 = 1;
+    col3 = 0;
+}