/*#############################################################

Program Name    : ex1_Keypad_simple
Author          : Grant Phillips
Date Modified   : 05/04/2016
Compiler        : ARMmbed
Tested On       : STM32F4-Discovery

Description     : Example program that demonstrates the use of
                  the Keypad class to use when a 4x4 keypad 
                  using a polling method.  
                  As the user presses a key, that character will 
                  be display via the Serial Wire Viewer as 
                  demonstration.  When the user presses
                  the '*' key, a newline will be displayed.
                  
                  The output is displayed on a PC using the
                  Serial Wire Viewer (SWV).  See the SWV examples
                  for an explanation of the use of this feature.

Requirements    : * STM32F4-Discovery Board
              
Circuit         : * 4x4 Keypad connected as follows:
                    COL1 (pin1)     -       PE15
                    COL2 (pin2)     -       PE14
                    COL3 (pin3)     -       PE13
                    COL4 (pin4)     -       PE12
                    ROW1 (pin5)     -       PE11
                    ROW2 (pin6)     -       PE10
                    ROW3 (pin7)     -       PE9
                    ROW4 (pin8)     -       PE8

                  * A wire link between PB3 and pin6 of the SWD
                    connector (CN2) as explained in the SWV
                    examples section

##############################################################*/

#include "mbed.h"
#include "Keypad.h"
#include "SWO.h"

Keypad kpad(PE_15, PE_14, PE_13, PE_12, PE_11, PE_10, PE_9, PE_8);
          //col1, col2, col3, col4, row1, row2, row3, row4
SWO_Channel SWO;

int main() {
    char key;
    int released = 1;                           //flag for indicating if a key was released (=1) or not (=0)
    
    while(1) {
        key = kpad.ReadKey();                   //read the current key pressed, but don't wait for a key to be pressed
        
        if(key == '\0')                         //if no key is pressed
            released = 1;                       //set the flag when all keys are released
            
        if((key != '\0') && (released == 1)) {  //if a key is pressed AND previous key was released
            if(key == '*')
                SWO.printf("\n");               //print newline when '*' is pressed
            else
                SWO.printf("%c", key);          //otherwise print the key pressed
                
            released = 0;                       //clear the flag to indicate that key is still pressed
        }
    }
}