Library Description

The library covers all the necessary functions to control 2x2 Key click board. 2x2 Key click
communicates with the target board through the AN, RST, CS, PWM and INT line. This library 
offers functions for detecting the states of any and every of the four keys on this click board.

Key functions:

• uint8_t c2x2key_t1State(); - Function gets state of AN pin on 2X2_Key Click board.
• uint8_t c2x2key_t2State();- Function gets state of RST pin on 2X2_Key Click board.
• uint8_t c2x2key_t3State(); - Function gets state of CS pin on 2X2_Key Click board.

Examples description

The application is composed of three sections:

• System Initialization - Initializes GPIO and LOG structures, sets AN, RST, CS, PWM and INT pins as input.
• Application Initialization -  Initialization driver enables GPIO and also starts write log.
• Application Task - (code snippet) This example demonstrates the use of 2X2 Key Click board.
       Detects whether any of the keys is pressed. Results are being sent to the Usart Terminal,
       where you can track changes.

void applicationTask() 
{
    t1State = c2x2key_t1State();

    if ( t1State == 1 && t1StateOld == 0 )    
    {
        mikrobus_logWrite( "  Key 1 pressed  ", _LOG_LINE );
        mikrobus_logWrite( "- - - - - - - - -", _LOG_LINE );
        t1StateOld = 1;
    }
       if ( t1State == 0 && t1StateOld == 1 )
    {
        t1StateOld = 0;
    }

    t2State = c2x2key_t2State();

    if ( t2State == 1 && t2StateOld == 0 )
    {
        mikrobus_logWrite( "  Key 2 pressed  ", _LOG_LINE );
        mikrobus_logWrite( "- - - - - - - - -", _LOG_LINE );
        t2StateOld = 1;
    }

    if ( t2State == 0 && t2StateOld == 1 )
    {
        t2StateOld = 0;
    }
    t3State = c2x2key_t3State();

    if ( t3State == 1 && t3StateOld == 0 )
    {
        mikrobus_logWrite( "  Key 3 pressed  ", _LOG_LINE );
        mikrobus_logWrite( "- - - - - - - - -", _LOG_LINE );
        t3StateOld = 1;
    if ( t3State == 0 && t3StateOld == 1 )
    {
        t3StateOld = 0;
    }

    t4State = c2x2key_t4State();

    if ( t4State == 1 && t4StateOld == 0 )
    {
        mikrobus_logWrite( "  Key 4 pressed  ", _LOG_LINE );
        mikrobus_logWrite( "- - - - - - - - -", _LOG_LINE );
        t4StateOld = 1;
    }
    if ( t4State == 0 && t4StateOld == 1 )
    {
        t4StateOld = 0;
    }
}   

Other mikroE Libraries used in the example:

• UART

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 click or RS232 click to connect to your PC, for development systems with no UART to USB interface available on the board. The terminal available in all MikroElektronika compilers, or any other terminal application of your choice, can be used to read the message