Lesson nr.06-Push Button

Hardware setup:
In this experiment we will make a demonstration with button library. The PORTB is used for this experiment (as output, for a leds) and RA6 (as imput, for button S2).
As usualy, button S1 and (pull-up) resistance with value of 4.7 K will provide the manual reset mode to the microcontroller. This arangement provides a standard schematic when we whant to include a button as input, current mode is with pull-up resistance, but also exist and with pull-down resistance which will not be used in our experiments, at least for the moment.
ICSP connector provides the connection between the programmer (PicKit 2) and microcontroller (PIC16F628A).



Circuit Diagram:
For those who want to build it on their own breadboard or other platform, here is the electronic scheme built in Eagle Cad, free version:

Software:
Here's a page from Button Library that specify buttons routines:

And as usualy, here is the C program written for MikroC PRO for PIC 2010 (version v4.15).

/*
'*******************************************************************************
'  Lesson nr.06:
'          Push Button
'  Written by:
'          Aureliu Raducu Macovei, 2010.
'  Description:
'          In this experiment we will make a demonstration with button library
'          The PORTB is used for this experiment (as output, for a leds)
'          and RA6 (as imput, for button).
'  Test configuration:
'    MCU:                        PIC16F628A
'    Test.Board:                 WB-106 Breadboard 2420 dots
'    SW:                         MikroC PRO for PIC 2010 (version v4.15)
'  Configuration Word
'    Oscillator:                 INTOSC:I/O on RA.6, I/O on RA.7
'    Watchdog Timer:             OFF
'    Power up Timer:             Disabled
'    Master Clear Enable:        Enabled
'    Browun Out Detect:          Enabled
'    Low Voltage Program:        Disabled
'    Data EE Read Protect:       Disabled
'    Code Protect:               OFF
'*******************************************************************************
*/
unsigned short oldstate;
void main()
{                                     // Main;
 TRISB = 0;                           // Set PORTB direction to be output;
 PORTB = 0xFF;                        // Turn OFF LEDs on PORTA;

 TRISA6_bit = 1;                      // Set PORT RB1 input for button;
 oldstate = 0;                        // Define value of oldstate;

do {
    if (Button(&PORTA,6,1,1)) oldstate = 1;
    Delay_ms(100);                                              //delay for prevent crash
    if (oldstate &&Button(&PORTA,6,1,0)) {
                                          PORTB = ~PORTB;       //invert state of PORTB
                                          oldstate = 0;
                                          }
    } while(1);                                                 //Infinite loop.
}