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

Program Name    : ex6_sw_leds_truth
Author          : Grant Phillips
Date Modified   : 12/01/2016
Compiler        : ARMmbed
Tested On       : STM32F4-Discovery

Description     : Reads the value of 3 switches and then 
                  controls the output of 8 LEDs as follows:
                  SW2 SW1 SW0 LEDs (0=OFF, 1=ON)
                   0   0   0  00000000
                   0   0   1  00001111
                   0   1   0  11110000
                   0   1   1  11111111
                   1   0   0  10101010
                   1   0   1  10101010
                   1   1   0  10101010
                   1   1   1  10101010    

Requirements    : * STM32F4-Discovery Board
              
Circuit         : * 8 LEDs connected to PD15 - PD8
                  * 3 switches connected to PE10(SW2), PE9(SW1) 
                    and PE8(SW0) with pullup resitors

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

#include "mbed.h"

BusOut myleds(PD_8, PD_9, PD_10, PD_11, PD_12, PD_13, PD_14, PD_15);
//            bit0  bit1  bit2   bit3   bit4   bit5   bit6   bit7 . . . 

DigitalIn switch2(PE_10);
DigitalIn switch1(PE_9);
DigitalIn switch0(PE_8);

int main() {
    uint8_t SW2, SW1, SW0;
    
    while(1) {
        /* due to the inverse logic of the input switch wiring, we need to invert the values
           read from the actual switches too to fit our truth table for this example    */
        SW2 = 1 - switch2;
        SW1 = 1 - switch1;
        SW0 = 1 - switch0;
        
        /* apply if..else for truth table outputs */
        if((SW2==0) && (SW1==0) && (SW0==0))
            myleds = 0x00;
        else if((SW2==0) && (SW1==0) && (SW0==1))
            myleds = 0x0f;
        else if((SW2==0) && (SW1==1) && (SW0==0))
            myleds = 0xf0;
        else if((SW2==0) && (SW1==1) && (SW0==1))
            myleds = 0xff;
        else                        
            myleds = 0xaa;   
    }
}