| 0,0 → 1,125 |
|---|
| /* |
| * Copyright (C) 2004 Darren Hutchinson (dbh@gbdt.com.au) |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU Library General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or (at your |
| * option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public |
| * License for more details. |
| * |
| * You should have received a copy of the GNU Library General Public License |
| * along with this software; see the file COPYING. If not, write to |
| * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| * MA 02111-1307, USA. |
| * |
| * $Id: pguide.c,v 1.1.1.1 2004/02/22 08:12:42 dbh Exp $ |
| */ |
| |
| /* This file contains the code that takes inputs from a parallel output |
| * guider (such as the SBIG ST-4) and uses them to make guiding |
| * adjustments. |
| */ |
| |
| #include <avr/io.h> |
| #include <avr/interrupt.h> |
| #include <inttypes.h> |
| |
| #include "eq6.h" |
| #include "combine.h" |
| #include "pguide.h" |
| |
| #define GUIDE_BITS (_BV(G_UP) | _BV(G_DN) | _BV(G_RT) | _BV(G_LT)) |
| |
| /* This module polls the input bits from the guider, applies some |
| * crude debouncing, and then applies the requested speed adjustment. |
| * |
| * This code assumes that the inputs are active low (i.e. they are connected |
| * to a relay or optocoupler connecting the "active" input to ground). |
| * |
| * The polling rate is generated by a 8-bit timer with /256 |
| */ |
| |
| /* pguideInit() initializes the timer used to poll the parallel guiding |
| * input bits and sets those bit as inputs. |
| * |
| * Passed: |
| * Nothing |
| * |
| * Returns: |
| * Nothing |
| * |
| */ |
| void |
| pguideInit(void) |
| { |
| /* Set guide bits as inputs with pullups */ |
| GUIDE_DDR &= ~GUIDE_BITS; |
| GUIDE_PORT |= GUIDE_BITS; |
| |
| /* Setup timer 2 to generate interrupts for PWM to the selected |
| * rate (in CTC mode) |
| */ |
| OCR2 = (CLK_RATE / GUIDE_RATE / 1024); |
| TCCR2 = _BV(WGM21) | _BV(CS22) | _BV(CS20); |
| |
| /* Enable interrupt generation from timer 2 */ |
| TIMSK |= _BV(OCIE2); |
| } |
| |
| /* pguideInt() is called whenever a timer 2 overflow interrupt occurs |
| * |
| * Passed: |
| * Nothing |
| * |
| * Returns: |
| * Nothing |
| */ |
| SIGNAL(SIG_OUTPUT_COMPARE2) |
| { |
| uint8_t guideBits; |
| |
| static uint8_t lastState = GUIDE_BITS; |
| static uint8_t lastUsed = GUIDE_BITS; |
| |
| /* Get the guide bits */ |
| guideBits = GUIDE_PIN & GUIDE_BITS; |
| |
| /* See if they're the same as the last set. If they are then we |
| * assume that the guide bits are stable |
| */ |
| if (guideBits != lastState) |
| { |
| /* Bits are changing */ |
| lastState = guideBits; |
| } |
| else if (lastUsed != lastState) |
| { |
| /* They're stable and different from the last used set, so |
| * update the guiding information |
| */ |
| |
| if ((guideBits & _BV(G_UP)) == 0) |
| rateInput.guideDecRate = SPEED_0_33_X; |
| else if ((guideBits & _BV(G_DN)) == 0) |
| rateInput.guideDecRate = -SPEED_0_33_X; |
| else |
| rateInput.guideDecRate = SPEED_0_X; |
| |
| if ((guideBits & _BV(G_RT)) == 0) |
| rateInput.guideRaRate = SPEED_0_33_X; |
| else if ((guideBits & _BV(G_LT)) == 0) |
| rateInput.guideRaRate = -SPEED_0_33_X; |
| else |
| rateInput.guideRaRate = SPEED_0_X; |
| |
| /* Update the overall rate */ |
| updateMountSpeed(); |
| |
| /* Update the last used state ('cuz we used it) */ |
| lastUsed = lastState; |
| } |
| } |