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#define __16f628a
#include"pic/pic16f628a.h"
/* Code to produce a wheel with one tooth. Why? 'Cos we'll
* beat everyone to a non-circular object. */
typedef unsigned int word;
//__CONFIG = 0x3f72;
//word at 0x2007 __CONFIG = 0x3D18;
typedef unsigned int config;
config at 0x2007 __CONFIG = _CP_OFF &
_WDT_OFF &
_BODEN_OFF &
_PWRTE_ON &
_INTRC_OSC_NOCLKOUT & // <--- this is the important one
_MCLRE_OFF &
_LVP_OFF;
unsigned char count; // Step shift for stepper 1
unsigned char count2; // Step shift for stepper 2
unsigned char inport;
unsigned char portFinal;
unsigned char tempa; // For fixing unwanted ADD to PORTA
unsigned char tempb; // For fixing broken (>>2)
unsigned char portFinal2;
unsigned int cdelay;
unsigned int goneForward;
unsigned int xStepCount=0;
unsigned char direction;
unsigned char direction2;
unsigned char xState;
#define XSTATE_INITIALISE 0
#define XSTATE_SYNC_BACKWARDS 1
#define XSTATE_SEEK_ENDSTOP 2
#define XSTATE_SEEK_CENTRE 3
#define XSTATE_AWAIT_BRS 4
#define XSTATE_START_GOING_ROUND 5
#define XSTATE_GOING_FORWARD 6
#define XSTATE_GOING_BACKWARD 7
#define XSTATE_GOING_ROUND 8
#define XSTATE_ROTATE_TOOTH 9
#define DIRECTION_NONE 0
#define DIRECTION_FORWARD 1
#define DIRECTION_BACKWARD 2
#define FORWARD_ENDSTOP_SENSOR 16 // A2
#define MAGNETIC_SENSOR 8 // A3
#define BRS_SENSOR 4 // A4
void main(void) {
// Set PORTA pins to input
CMCON=7;
// Set the I/O Direction magick
TRISB = 0;
TRISA = BRS_SENSOR+MAGNETIC_SENSOR+FORWARD_ENDSTOP_SENSOR;
count = 1;
count2 = 1;
xStepCount=0;
direction = DIRECTION_NONE;
direction2 = DIRECTION_NONE;
xState=XSTATE_INITIALISE;
while(1) {
switch (xState) {
case XSTATE_INITIALISE:
// First, set counters etc. so we traverse 100 steps back.
xState=XSTATE_SYNC_BACKWARDS;
direction = DIRECTION_BACKWARD;
direction2 = DIRECTION_NONE;
xStepCount=100;
break;
case XSTATE_SYNC_BACKWARDS:
// Until our step count is zero, we keep going.
if (xStepCount>0) {
xStepCount-=1;
} else {
// We hit zero. Seek the endstop
xState=XSTATE_SEEK_ENDSTOP;
direction = DIRECTION_FORWARD;
}
break;
case XSTATE_SEEK_ENDSTOP:
// If we bump into it, start our long march back.
inport=PORTA;
inport=inport&FORWARD_ENDSTOP_SENSOR;
if (inport==FORWARD_ENDSTOP_SENSOR) {
xState=XSTATE_SEEK_CENTRE;
direction = DIRECTION_BACKWARD;
xStepCount=3000;
}
break;
case XSTATE_SEEK_CENTRE:
// When our long march is done, start going around.
if (xStepCount>0) {
xStepCount--;
} else {
// We hit zero. Now we can draw ovals etc.
direction = DIRECTION_NONE;
xState=XSTATE_AWAIT_BRS;
}
break;
case XSTATE_AWAIT_BRS:
// Hang fire until the user hits the big, red switch (BRS)
inport=PORTA;
inport=inport&BRS_SENSOR;
if (inport==BRS_SENSOR) {
xState=XSTATE_START_GOING_ROUND;
}
break;
case XSTATE_START_GOING_ROUND:
direction = DIRECTION_NONE;
direction2 = DIRECTION_FORWARD;
xState=XSTATE_GOING_ROUND;
// Drop in to state below...
case XSTATE_GOING_ROUND:
/* See if someone is waving a magnet. */
inport=PORTA;
inport&=MAGNETIC_SENSOR;
if (inport!=0) {
direction=DIRECTION_FORWARD;
goneForward=0;
// Stop the turntable.
direction2=DIRECTION_NONE;
xState=XSTATE_GOING_FORWARD;
}
break;
case XSTATE_GOING_FORWARD:
goneForward+=1;
/* One revolution of the turntable is 20x57 steps = 1140
* So 1/4 that is 285. Coming back 285 gives an ovoid
* bulge over 1/2 a revolution. */
if (goneForward > 130) {
direction=DIRECTION_NONE;
direction2=DIRECTION_FORWARD;
xState=XSTATE_ROTATE_TOOTH;
xStepCount=130;
}
break;
case XSTATE_ROTATE_TOOTH:
/* Revolve a little. */
xStepCount--;
if (xStepCount == 0) {
direction=DIRECTION_BACKWARD;
direction2=DIRECTION_NONE;
xState=XSTATE_GOING_BACKWARD;
}
break;
case XSTATE_GOING_BACKWARD:
// Backtrack to complete tooth.
goneForward-=1;
if (goneForward == 0) {
// Start the turntable again.
direction2=DIRECTION_NONE;
xState=XSTATE_START_GOING_ROUND;
break;
}
break;
}
// Shift back or forth, depending on direction.
portFinal=0;
switch (direction) {
case DIRECTION_BACKWARD:
portFinal = count;
count<<=1;
break;
case DIRECTION_FORWARD:
portFinal = count;
count>>=1;
break;
case DIRECTION_NONE:
portFinal=0;
break;
}
// At the moment, we can only move forwards with stepper 2
if (direction2==DIRECTION_NONE) {
portFinal2=0;
} else {
count2<<=1;
// Only change the first 4 bits of steppers 1 & 2.
if (count2>8) {
count2=1;
}
portFinal2=count2;
}
// Only change the first 4 bits of steppers 1 & 2.
if (count>8) {
count=1;
} else if (count==0) {
count=8;
}
/* Put 2 stepper outputs on separate ports.
* Drive in this order: A6,A7,A0,A1
* tempa is for hiding a compiler bug. PORTA is read only!
*/
tempa=portFinal&3; // These two go to A6 & A7
tempa=tempa<<6;
// Mask off the lower 2 bits and add them into the mix.
tempb=(portFinal>>2);
tempa=tempa|tempb;//((portFinal>>2)&3);
PORTA=tempa;
PORTB=(portFinal2<<4);
// Fast, or slow?
//cdelay=4000;
cdelay=650; // 500 is maximum speed, I think.
while ((--cdelay)>0);
}
}
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