1 /* $Id: ircontrol.c,v 1.5 2010/06/30 19:38:28 simimeie Exp $
2 * Functions for the infrared receiver
4 * The infrared receiver is connected to PB0 / PCINT0.
8 #include <avr/interrupt.h>
13 /* NOTE1: Note that the signal we get from the sensor is inverted. If we
14 * read a zero, it means there was infrared on, if we read a one, infrared
16 * NOTE2: Only NEC is implemented here right now, because MY remote uses
17 * that protocol. However, there may be references to RC5 because I had
18 * already thought about that and just left them for possible future use. */
20 /* For RC5, one bit length is 1778 us, when it toggles we see half
22 * that equals around 7100 cpu cycles at 8 MHz. */
23 #define RC5HALFLENINCYCLES ((CPUFREQ * 889UL) / 1000000UL)
25 /* For NEC, we start with a 9000 us pulse, then 4500 us silence.
26 * Then the bits follow:
27 * a 1 is a 560 us pulse followed by 1690 us of silence (=2250 us total).
28 * a 0 is a 560 us pulse followed by 560 us of silence (=1120 us total).
29 * These values equal the following cpu cycle counts:
30 * 9000 us = 72000 cc, 4500 us = 36000 cc, 560 us = 4480, 1690 us = 13520 cc
31 * When the key stays pressed, it is not resubmitted, but instead a special
32 * "repeat" code is sent. That is: 9000 us pulse, 2250 us silence, 560 us
35 #define NECSTARTLEN1 ((CPUFREQ * 9UL) / 1000UL)
36 #define NECSTARTLEN2 ((CPUFREQ * 45UL) / 10000UL)
37 #define NECPULSELEN ((CPUFREQ * 56UL) / 100000UL)
38 #define NECZEROLEN ((CPUFREQ * 112UL) / 100000UL)
39 #define NECONELEN ((CPUFREQ * 225UL) / 100000UL)
40 #define NECREPEATLEN ((CPUFREQ * 225UL) / 100000UL)
42 /* the NEC code contains 4 bytes, sent with LSB first:
43 * 0+1 are either the "extended address" or "address and inverted address".
44 * 2 is the command code
45 * 3 is the inverted command code
48 static struct timestamp last0irqts;
49 static struct timestamp last1irqts;
50 static uint8_t lastpin = 0xff;
51 static uint8_t codebytes[4];
52 static uint8_t curcodebit = 0xff;
53 static uint8_t lastcommand = 0xff;
54 static uint8_t repeatcommand = 0xff;
55 static uint16_t repeatticks = 0;
56 /* Repeat after this many ticks (70 = 0.5s) */
57 #define REPEATAFTERTICKS 100
60 root@moodlight# !NSB! 11111111 00001000 11011111 00100000 (r)
61 root@moodlight# !NSB! 11111111 00001000 01011111 10100000 (g)
62 root@moodlight# !NSB! 11111111 00001000 10011111 01100000 (b)
63 root@moodlight# !NSB! 11111111 00001000 00011111 11100000 (w)
68 struct timestamp curirqts;
69 uint32_t ts1diff; /* distance from last 1 */
70 uint32_t ts0diff; /* distance from last 0 */
73 if (v == lastpin) { /* No change visible - spurious interrupt */
76 curirqts = gettimestamp_noirq();
77 ts1diff = ((uint32_t)curirqts.ticks << 16) + curirqts.partticks;
79 ts1diff -= ((uint32_t)last1irqts.ticks << 16) + last1irqts.partticks;
80 ts0diff -= ((uint32_t)last0irqts.ticks << 16) + last0irqts.partticks;
81 if (v) { /* Infrared just went away! */
82 if ((ts1diff >= (( 8 * NECSTARTLEN1) / 10))
83 && (ts1diff <= ((12 * NECSTARTLEN1) / 10))) {
85 /* console_printpgm_P(PSTR("!NSB!")); */
86 curcodebit = 0xfe; /* Wait for second part of start sequence */
88 if (curcodebit <= 32) { /* We're in a decoding attempt, so */
89 /* Check pulse length */
90 if ((ts1diff < (( 8 * NECPULSELEN) / 10))
91 || (ts1diff > ((12 * NECPULSELEN) / 10))) {
96 if (curcodebit == 32) {
97 if (codebytes[2] != (codebytes[3] ^ 0xff)) {
98 console_printpgm_P(PSTR("!CRC!"));
100 /* Successful decode! */
101 lastcommand = codebytes[2];
102 repeatcommand = codebytes[2];
103 repeatticks = curirqts.ticks;
104 console_printpgm_P(PSTR(" DEC>"));
105 console_printhex8(codebytes[0]);
106 console_printhex8(codebytes[1]);
107 console_printhex8(codebytes[2]);
108 console_printhex8(codebytes[3]);
112 last0irqts = curirqts;
113 } else { /* Infrared went on */
114 if ((ts1diff >= (( 8 * NECZEROLEN) / 10))
115 && (ts1diff <= ((12 * NECZEROLEN) / 10))) {
116 /* console_printpgm_P(PSTR("0")); */
117 if (curcodebit < 32) {
120 } else if ((ts1diff >= (( 8 * NECONELEN) / 10))
121 && (ts1diff <= ((12 * NECONELEN) / 10))) {
122 /* console_printpgm_P(PSTR("1")); */
123 if (curcodebit < 32) {
124 codebytes[curcodebit >> 3] |= (1 << (curcodebit & 0x07));
129 } else if ((ts0diff >= (( 8 * NECSTARTLEN2) / 10))
130 && (ts0diff <= ((12 * NECSTARTLEN2) / 10))) {
131 if (curcodebit == 0xfe) { /* voila, correct start sequence */
133 codebytes[0] = codebytes[1] = codebytes[2] = codebytes[3] = 0;
135 } else if ((ts0diff >= (( 8 * NECREPEATLEN) / 10))
136 && (ts0diff <= ((12 * NECREPEATLEN) / 10))) {
137 if (curcodebit == 0xfe) {
138 console_printpgm_P(PSTR(".REP."));
139 if ((curirqts.ticks - repeatticks) > REPEATAFTERTICKS) {
140 if ((repeatcommand == 0x00) || (repeatcommand == 0x01)) {
141 /* Only the up/down arrows are allowed to be repeated */
142 lastcommand = repeatcommand;
147 last1irqts = curirqts;
150 console_printpgm_P(PSTR("!"));
151 console_printhex8(tsdiff >> 24);
152 console_printhex8(tsdiff >> 16);
153 console_printhex8(tsdiff >> 8);
154 console_printhex8(tsdiff >> 0);
155 console_printpgm_P(PSTR("!"));
158 if (tsdiff > ((24 * HALFRC5LENINCYCLES) / 10)) {
159 /* Start of new transmission */
160 console_printpgm_P(PSTR("!1["));
161 console_printhex8(v);
163 } else if (tsdiff > ((15 * HALFRC5LENINCYCLES) / 10)) {
164 /* Different bit than last time */
167 console_printpgm_P(PSTR("1"));
169 console_printpgm_P(PSTR("0"));
171 } else if ((tsdiff < ((15 * HALFRC5LENINCYCLES) / 10))
172 && (tsdiff > (( 5 * HALFRC5LENINCYCLES) / 10))) {
173 /* Same bit as last time */
175 console_printpgm_P(PSTR("1"));
177 console_printpgm_P(PSTR("0"));
184 void ircontrol_init(void)
186 /* Activate pullup */
190 /* Enable pin change interrupt 0 (=PB0) in pcint0 */
191 PCMSK0 |= _BV(PCINT0);
194 uint8_t ircontrol_getlastcommand(void)