git.zerfleddert.de Git - fnordlicht-mini/blob - firmware/fnordlicht-controller/ir.c

   1 /*
   2  *   ox - infrared to usb keyboard/mouse adapter
   3  *
   4  *   by Alexander Neumann <alexander@lochraster.org>
   5  *
   6  * inspired by InfraHID by Alex Badea,
   7  * see http://vamposdecampos.googlepages.com/infrahid.html
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  *
  22  * For more information on the GPL, please go to:
  23  * http://www.gnu.org/copyleft/gpl.html
  24  */
  25
  26 #include <avr/io.h>
  27 #include <avr/interrupt.h>
  28 #include <avr/pgmspace.h>
  29 #include <stdbool.h>
  30 #include <util/crc16.h>
  31 #include "config.h"
  32 #include "globals.h"
  33 #include "../common/common.h"
  34 #include "usb.h"
  35 #include "ir.h"
  36 #include "ir-cluster.h"
  37 #include "ui.h"
  38
  39 /* macro magic */
  40 #define IR_DDR      _DDRPORT(IR_PORTNAME)
  41 #define IR_PORT     _OUTPORT(IR_PORTNAME)
  42
  43 #if IR_INTNUM < 8
  44 #   define IR_BANK      0
  45 #   define IR_VECT      PCINT0_vect
  46 #elif IR_INTNUM < 16
  47 #   define IR_BANK      1
  48 #   define IR_VECT      PCINT1_vect
  49 #else
  50 #   define IR_BANK      2
  51 #   define IR_VECT      PCINT2_vect
  52 #endif
  53
  54 #define IR_INT          (IR_INTNUM - IR_BANK * 8)
  55 #define IR_PCIE         _PCIE(IR_BANK)
  56 #define IR_PCIF         _PCIF(IR_BANK)
  57 #define IR_PCMSK        _PCMSK(IR_BANK)
  58
  59 /* 8 should be enough for everybody! */
  60 #define MAX_CLUSTERS 8
  61
  62 /* internal state machine */
  63 static enum {
  64     READY = 0,
  65     LISTEN = 1,
  66     DONE = 2,
  67 } state;
  68
  69 volatile struct ir_global_t ir_global;
  70
  71 void ir_init(void)
  72 {
  73     /* initialize input pin (with pullup) */
  74     IR_DDR &= ~_BV(IR_PIN);
  75     IR_PORT |= _BV(IR_PIN);
  76
  77     /* configure timer1 with prescaler 64 and CTC for measuring ir timings */
  78     TCCR1B = _BV(CS11) | _BV(CS10) | _BV(WGM12);
  79     /* configure timer action after 20ms: 20mhz/64/50 */
  80     OCR1A = F_CPU/50/64;
  81 }
  82
  83 void ir_set_mode(enum ir_mode_t mode)
  84 {
  85     if (ir_global.mode != IR_DISABLED && mode == IR_DISABLED) {
  86         /* disable pin change interrupt */
  87         IR_PCMSK &= ~_BV(IR_INT);
  88         PCICR &= ~_BV(IR_PCIE);
  89
  90         /* clear interrupt flags */
  91         TIFR1 = TIFR1;
  92     } else if (ir_global.mode == IR_DISABLED && mode != IR_DISABLED) {
  93         /* clear interrupt flags */
  94         TIFR1 = TIFR1;
  95
  96         /* reset variables */
  97         ir_global.pos = 0;
  98         state = READY;
  99
 100         /* enable pin change interrupt */
 101         IR_PCMSK |= _BV(IR_INT);
 102         PCICR |= _BV(IR_PCIE);
 103     }
 104
 105     ir_global.mode = mode;
 106
 107     if (mode == IR_DECODE || mode == IR_RAW)
 108         ui_blink(0, 0x5);
 109 }
 110
 111 ISR(IR_VECT, ISR_NOBLOCK)
 112 {
 113     /* store code */
 114     uint16_t value = TCNT1;
 115     TCNT1 = 0;
 116
 117     /* do not store the first 'off' timing value */
 118     if (state == READY)
 119         state = LISTEN;
 120     else if (state == LISTEN) {
 121         ir_global.time[ir_global.pos++] = value;
 122
 123         /* check if we reached the end of the array */
 124         if (ir_global.pos == MAX_CODE_LENGTH)
 125             state = DONE;
 126     }
 127 }
 128
 129 void ir_poll(void)
 130 {
 131     if (ir_global.mode == IR_DISABLED)
 132         return;
 133
 134     /* check for timeout */
 135     if (TIFR1 & _BV(OCF1A)) {
 136         /* clear interrupt flag */
 137         TIFR1 = _BV(OCF1A);
 138
 139         /* if ir has been detected, process code, else return to listening */
 140         if (ir_global.pos > 1) {
 141             state = DONE;
 142
 143             /* set last timing to zero */
 144             if (ir_global.pos % 2 == 0)
 145                 ir_global.time[ir_global.pos-1] = 0;
 146             else
 147                 ir_global.time[ir_global.pos++] = 0;
 148         } else
 149             state = READY;
 150     }
 151
 152     /* if code is complete, process! */
 153     if (state == DONE) {
 154         /* compute clusters */
 155         if (ir_global.mode == IR_RECEIVE || ir_global.mode == IR_DECODE) {
 156             uint16_t cluster_on[MAX_CLUSTERS];
 157             uint16_t cluster_off[MAX_CLUSTERS];
 158
 159             uint8_t con = ir_cluster(&ir_global.time[0], ir_global.pos/2, &cluster_on[0], MAX_CLUSTERS);
 160             uint8_t coff = ir_cluster(&ir_global.time[1], ir_global.pos/2-1, &cluster_off[0], MAX_CLUSTERS);
 161
 162             for (uint8_t i = 0; i < ir_global.pos/2; i++) {
 163                 uint8_t data_on = ir_min_cluster(ir_global.time[2*i], cluster_on, con);
 164                 uint8_t data_off = ir_min_cluster(ir_global.time[2*i+1], cluster_off, coff);
 165
 166                 ir_global.time[i] = data_on | (data_off << 8);
 167             }
 168
 169             ir_global.pos /= 2;
 170         }
 171
 172         if (ir_global.mode == IR_RECEIVE) {
 173             uint16_t crc = 0;
 174             for (uint8_t i = 0; i < ir_global.pos; i++) {
 175                 crc = _crc16_update(crc, LO8(ir_global.time[i]));
 176                 crc = _crc16_update(crc, HI8(ir_global.time[i]));
 177             }
 178
 179             /* remember code and length */
 180             ir_global.last = crc;
 181             ir_global.length = ir_global.pos/2;
 182
 183             /*
 184              *  insert code evaluation here...
 185              */
 186
 187             ui_blink(0x1, 0);
 188
 189             ir_global.pos = 0;
 190             state = READY;
 191         } else {
 192             ui_blink(0, 0x1);
 193             ir_set_mode(IR_DISABLED);
 194         }
 195     }
 196 }