c1351.h File Reference

C1350 and C1351 interface. More...

#include <inttypes.h>

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Enumerations
enum	_potmode { POTMOUSE_C1351 = 0, POTMOUSE_JOYSTICK }
Functions
void	potmouse_init ()
	Init all C1351-related I/O and interrupts, but don't start yet.
void	potmouse_start (uint8_t mode)
	Set mode and start working.
void	potmouse_movt (int16_t dx, int16_t dy, uint8_t button)
	Report movement from PS2 mouse.
void	potmouse_zero (uint16_t zero)
	Define zero-point in time (normally 320us).

---

Detailed Description

C1350 and C1351 interface.

---

Enumeration Type Documentation

enum _potmode

Mouse mode: 1351 (analog, proportional) or joystick

See potmouse_start()

Enumerator:

POTMOUSE_C1351
POTMOUSE_JOYSTICK

              {
    POTMOUSE_C1351 = 0,             //<! proportional mode
    POTMOUSE_JOYSTICK               //<! joystick mode
};

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Function Documentation

void potmouse_init

(

)

Init all C1351-related I/O and interrupts, but don't start yet.

                     {
    // Joystick outputs, all to Z and no pullup
    JOYPORT &= ~(_BV(JOYFIRE) | _BV(JOYUP) | _BV(JOYDOWN) | _BV(JOYLEFT) | _BV(JOYRIGHT)); 
    JOYDDR  &= ~(_BV(JOYFIRE) | _BV(JOYUP) | _BV(JOYDOWN) | _BV(JOYLEFT) | _BV(JOYRIGHT));
    
    // SID sensing port
    SENSEDDR  &= ~_BV(POTSENSE); // SENSE is input
    SENSEPORT &= ~_BV(POTSENSE); // pullup off, hi-biased by OC1B

    // SID POTX/POTY port
    POTPORT &= ~(_BV(POTX) | _BV(POTY));
    POTDDR  &= ~(_BV(POTX) | _BV(POTY));

    // prepare INT1
    GICR &= ~_BV(INT1);                     // disable INT1
    MCUCR &= ~(_BV(ISC11)|_BV(ISC10));  
    MCUCR |= _BV(ISC11);                    // ISC11:ISC10 == 10, @negedge   
    
    mode = POTMOUSE_C1351;
}

void potmouse_movt	(	int16_t	dx,
		int16_t	dy,
		uint8_t	button
	)

Report movement from PS2 mouse.

                                                           {
    uint16_t a, b;
    
    switch (mode) {
        case POTMOUSE_C1351:
            potmouse_xcounter = (potmouse_xcounter + dx) & 077; // modulo 64
            potmouse_ycounter = (potmouse_ycounter + dy) & 077;
        
            (button & 001) ? (JOYDDR |= _BV(JOYFIRE)) : (JOYDDR &= ~_BV(JOYFIRE));
            (button & 002) ? (JOYDDR |= _BV(JOYUP))   : (JOYDDR &= ~_BV(JOYUP));
            (button & 004) ? (JOYDDR |= _BV(JOYDOWN)) : (JOYDDR &= ~_BV(JOYDOWN));
            
            // scale should be 2x here, but for this particular chip, 66 counts work better where
            // 64 counds should be. so 66/64=100/96 and times two
            a = ocr_zero + potmouse_ycounter*200/96;
            b = ocr_zero + potmouse_xcounter*200/96;
            
            ocr1a_load = a;
            ocr1b_load = b;
            break;
        case POTMOUSE_JOYSTICK:
            JOYDDR  &= ~(_BV(JOYFIRE) | _BV(JOYUP) | _BV(JOYDOWN) | _BV(JOYLEFT) | _BV(JOYRIGHT));

            (dx < 0) ? (JOYDDR |= _BV(JOYLEFT)) : (JOYDDR &= ~_BV(JOYLEFT));
            (dx > 0) ? (JOYDDR |= _BV(JOYRIGHT)): (JOYDDR &= ~_BV(JOYRIGHT));
            (dy < 0) ? (JOYDDR |= _BV(JOYDOWN)) : (JOYDDR &= ~_BV(JOYDOWN));
            (dy > 0) ? (JOYDDR |= _BV(JOYUP))   : (JOYDDR &= ~_BV(JOYUP));
            (button & 001) ? (JOYDDR |= _BV(JOYFIRE)) : (JOYDDR &= ~_BV(JOYFIRE));
            (button & 002) ? (POTDDR |= _BV(POTX)) : (POTDDR &= ~_BV(POTX));
  
            TCNT1 = 65535-256;
            TCCR1A = 0;
            TCCR1B = _BV(CS12)|_BV(CS10);
            TIFR |= _BV(TOV1);
            TIMSK |= _BV(TOIE1);
            break;
    }
}

void potmouse_start

(

uint8_t

mode

)

Set mode and start working.

Parameters:

mode

see _potmode

                               {
    mode = m;
    switch (mode) {
        case POTMOUSE_C1351:
            // Initialize Timer1 and use OC1A/OC1B to output values
            // don't count yet    
            TCCR1B = 0; 
            
            // POTX/Y normally controlled by output compare unit
            // initially should be pulled up to provide high bias on SENSE pin
            POTDDR  |= _BV(POTX) | _BV(POTY);   // enable POTX/POTY as outputs
            POTPORT |= _BV(POTX) | _BV(POTY);   // output "1" on both
            
            GIFR |= _BV(INTF1);                     // clear INT1 flag
            GICR |= _BV(INT1);                      // enable INT1
            break;
        case POTMOUSE_JOYSTICK:
            // Joystick emulation
            // close directional pins for ~20ms while there is movement
            TCCR1B = 0;
            TCCR1A = 0;
            
            break;
    }
}

void potmouse_zero

(

uint16_t

zero

)

Define zero-point in time (normally 320us).

                                  {
    ocr_zero = zero;
}