1 #ifndef QMSK_SWITCH_H

     2 #define QMSK_SWITCH_H

     3 

     4 #include "stdlib.h"

     5 

     6 extern byte switch_mask;

     7 

     8 /*

     9  * Setup switch input triggering on SWITCH_DDR/PORT/PIN using SWITCH_PCMSK/PCIE/PCIF interrupts.

    10  */

    11 void switch_init (void)

    12 {

    13     switch_mask = SWITCH_MASK;

    14 

    15     // input mode

    16     byte bit = 1;

    17 

    18     for (byte i = 0; i < 8; i++) {

    19         if (SWITCH_MASK & bit) {

    20             cbi(SWITCH_DDR, i);

    21 

    22             // pull-up

    23             sbi(SWITCH_PORT, i);

    24         }

    25 

    26         bit <<= 1;

    27     }

    28 

    29     // interrupt mask for port

    30     *SWITCH_PCMSK = SWITCH_MASK;

    31 

    32     // enable interrupts

    33     sbi(&PCICR, SWITCH_PCIE);

    34 }

    35 

    36 /*

    37  * Update switch state if changed.

    38  *

    39  * Returns 1 if changed, 0 if no changes.

    40  *

    41  * TODO: debouncing

    42  */

    43 byte switch_read (byte *sp);

    44 

    45 #endif