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#include "xc.h"
void initKeyPad(void) {
TRISA = 0b0000000000011111; //set port A to inputs,
LATA = 0x0000; //Set all of port A to LOW
CNPU1bits.CN11PUE = 1;
CNPU1bits.CN12PUE = 1;
CNPU1bits.CN13PUE = 1;
CNPU1bits.CN14PUE = 1;
}
void padDelay(long n) {
for (n=n; n>0; n--) {
asm("nop");
}
}
// 1 2 3 4 5 6 7 8
// RA0 RA1 RA2 RA3 RB15 RB14 RB13 RB12
char readKeyPadRAW(void) {
int i;
char num;
num = '\0';
LATB |= (0b1111 << 12);
padDelay(5);
for (i = 0; i < 4; i++) {
LATB ^= 0b1 << (15 - i);
padDelay(10);
switch (i) {
case 0:
switch (num) {
case 0b1110:
return 'A';
break;
case 0b1101:
return '3';
break;
case 0b1011:
return '2';
break;
case 0b111:
return '1';
break;
} break;
case 1:
switch (num) {
case 0b1110:
return 'b';
break;
case 0b1101:
return '6';
break;
case 0b1011:
return '5';
break;
case 0b111:
return '4';
break;
} break;
case 2:
switch (num) {
case 0b1110:
return 'C';
break;
case 0b1101:
return '9';
break;
case 0b1011:
return '8';
break;
case 0b111:
return '7';
break;
} break;
case 3:
switch (num) {
case 0b1110:
return 'd';
break;
case 0b1101:
return 'E';
break;
case 0b1011:
return '0';
break;
case 0b111:
return 'F';
break;
} break;
} //END switch(i);
LATB |= (0b1111 << 12);
}
return '\0';
}
/*
Outputs<8:5> = 0b0111; // Set Row 1 output Low
delay(1us); // this delay could be lower, probably 2-3 cycles
RowOne = Inputs<4:1>; // returns 0b1111 (no buttons pressed in row 1)
Outputs<8:5> = 0b1011; // Set Row 2 output Low
delay(1us);
RowTwo = Inputs<4:1>; // returns 0b1101 (the ?6? key was pressed!)
...
Outputs<8:5> = 0b1110; // Set Row 4 output Low
delay(1us);
RowFour = Inputs<4:1>; // returns 0b1111 (no buttons pressed in row 4)
*/
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