src/ignitionISRs.c

   1 /*      FreeEMS - the open source engine management system
   2
   3         Copyright 2008 Fred Cooke
   4
   5         This file is part of the FreeEMS project.
   6
   7         FreeEMS software is free software: you can redistribute it and/or modify
   8         it under the terms of the GNU General Public License as published by
   9         the Free Software Foundation, either version 3 of the License, or
  10         (at your option) any later version.
  11
  12         FreeEMS software is distributed in the hope that it will be useful,
  13         but WITHOUT ANY WARRANTY; without even the implied warranty of
  14         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15         GNU General Public License for more details.
  16
  17         You should have received a copy of the GNU General Public License
  18         along with any FreeEMS software.  If not, see http://www.gnu.org/licenses/
  19
  20         We ask that if you make any changes to this file you email them upstream to
  21         us at admin(at)diyefi(dot)org or, even better, fork the code on github.com!
  22
  23         Thank you for choosing FreeEMS to run your engine! */
  24
  25
  26 /**     @file ignitionISRs.c
  27  * @ingroup interruptHandlers
  28  *
  29  * @brief Turn ignition channels on and off
  30  *
  31  * This currently semi-working but broken code is intended to one day provide
  32  * multi-channel ignition capabilities. The basic method will be to turn a pin
  33  * or set of pins on or another pin or set of pins off during each run of the
  34  * appropriate handler. Each run will be triggered either by the scheduler and
  35  * possibly this code itself as well. Currently it does not work correctly and
  36  * isn't suitable for actual use as an ignition control solution.
  37  */
  38
  39
  40 #define IGNITIONISRS_C
  41 #include "inc/freeEMS.h"
  42 #include "inc/interrupts.h"
  43
  44
  45 /* Summary of intended ignition timing scheme
  46  *
  47  * Set TWO PIT timers based on a reference point (probably single cam trigger or optionally toggle bit based on missing tooth on crank)
  48  * Arm one PIT timer interrupt to trigger when we need to start dwelling
  49  * Arm the other PIT timer interrupt to trigger when we need to fire
  50  * Configure a variable to point to the next pin to turn on for dwell
  51  * Configure a variable to point to the next pin to turn off to fire
  52  * On PIT interrupt for dwell check to see that spark should have finished
  53  * If so, turn on coil to dwell
  54  * If not, reset dwell timer interrupt for end of spark event
  55  * On PIT interrupt for spark, turn off coil (amything else?)
  56  * Repeat for each cylinder.
  57  */
  58
  59 /* Further consideration to spark duration and dwell starting possibly needs to be done. */
  60
  61 /* further reading : ftp://ftp-sop.inria.fr/esterel/pub/papers/FDL99-camready.pdf section 4.1 has a nice diagram */
  62
  63
  64 /**     @brief Ignition dwell control
  65  *
  66  * This function turns ignition pins on to dwell when required.
  67  *
  68  * @author Fred Cooke
  69  *
  70  * @todo TODO make this actually work.
  71  */
  72 void IgnitionDwellISR(void)
  73 {
  74         // clear flag
  75         PITTF = DWELL_ENABLE;
  76
  77         // start dwelling asap
  78         PORTS_BA |= dwellStartMasks[nextDwellChannel];
  79
  80         if(dwellQueueLength == 0){
  81                 // turn off the int
  82                 PITINTE &= DWELL_DISABLE;
  83
  84                 // disable channels
  85                 PITCE &= DWELL_DISABLE;
  86         }else{
  87                 // reduce queue length by one
  88                 dwellQueueLength--;
  89
  90                 // increment channel counter to next channel
  91                 if(nextDwellChannel < (fixedConfigs2.combustionEventsPerEngineCycle - 1)){
  92                         nextDwellChannel++; // if not the last channel, increment
  93                 }else{
  94                         nextDwellChannel = 0; // if the last channel, reset to zero
  95                 }
  96
  97                 // if the queue length after decrement is greater than 0 then we need to load the timer, if it is zero and we decremented, the timer was already loaded.
  98                 if(dwellQueueLength > 0){
  99                         if(dwellQueueLength > 8){ // TODO ???? why 8 ???? 12 or combustion events per... or ?
 100                                 //throw a nasty error of some sort for index out of range issue that should never occur (for now just light a LED)
 101                                 PORTS |= 0x20;
 102                         }else{
 103                                 // load the timer if the index is good
 104                                 PITLD0 = queuedDwellOffsets[dwellQueueLength - 1];
 105                         }
 106                 }
 107         }
 108
 109         // blink a led
 110         PORTS ^= 0x80;
 111 }
 112
 113
 114 /**     @brief Ignition discharge control
 115  *
 116  * This function turns ignition pins off to discharge when required.
 117  *
 118  * @author Fred Cooke
 119  *
 120  * @todo TODO make this actually work.
 121  */
 122 void IgnitionFireISR(void)
 123 {
 124         // clear flag
 125         PITTF = IGNITION_ENABLE;
 126
 127         // fire the coil asap
 128         PORTS_BA &= ignitionMasks[nextIgnitionChannel];
 129
 130         if(ignitionQueueLength == 0){
 131                 // turn off the int
 132                 PITINTE &= IGNITION_DISABLE;
 133
 134                 // disable channels
 135                 PITCE &= IGNITION_DISABLE ;
 136         }else{
 137                 // reduce queue length by one
 138                 ignitionQueueLength--;
 139
 140                 // increment channel counter to next channel
 141                 if(nextIgnitionChannel < (fixedConfigs2.combustionEventsPerEngineCycle - 1)){
 142                         nextIgnitionChannel++; // if not the last channel, increment
 143                 }else{
 144                         nextIgnitionChannel = 0; // if the last channel, reset to zero
 145                 }
 146
 147                 // if the queue length after decrement is greater than 0 then we need to load the timer, if it is zero and we decremented, the timer was already loaded.
 148                 if(ignitionQueueLength > 0){
 149                         if(ignitionQueueLength > fixedConfigs2.combustionEventsPerEngineCycle){ // TODO as above!!!!!!!!!!
 150                                 //throw a nasty error of some sort for index out of range issue that should never occur (for now just light a LED)
 151                                 PORTS |= 0x10;
 152                         }else{
 153                                 // load the timer if the index is good
 154                                 PITLD0 = queuedIgnitionOffsets[ignitionQueueLength - 1];
 155                         }
 156                 }
 157         }
 158
 159         // blink a led
 160         PORTS ^= 0x40;
 161 }