how to decode raw IR data using lirc on raspberry pi 3 - raspberry-pi

Question

I've been trying to decode my IR raw data but always getting unknown code. i used
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#define SHORT 600
#define LONG 300
#define MARGIN 200
#define INTRO 3500
#define INTRO2 1700
#define SEPARATOR 9880
char decode(int val1, int val2){
if (abs(val1 - INTRO) < MARGIN && abs(val2 -
INTRO2) < MARGIN)
return '[';
if (abs(val1 - SHORT) < MARGIN && abs(val2 -
SHORT) < MARGIN)
return '0';
if (abs(val1 - SHORT) < MARGIN && abs(val2 -
LONG) < MARGIN)
return '1';
if (abs(val1 - SHORT) < MARGIN && abs(val2 -
SEPARATOR) < MARGIN)
return ']';
}
int abs(int val){
if (val < 0)
return -val;
else
return val;
}
int main(int argc, char** argv){
if (argc < 3){
printf("usage = %s fileName output\n",
argv[0]);
exit(0);
}
int val1, val2;
char delims[] = " ";
char *result = NULL;
FILE* f = fopen(argv[1],"r");
FILE* out = fopen(argv[2],"w");
char line[256];
int index = 0;
char* nIndex = 0;
while (fgets(line, 256, f) != NULL){
result = strtok( line, delims );
index = 0;
while( result != NULL ) {
//printf( "result[%d] is \"%s\"\n",
index, result );
if (index & 1){
if (nIndex = strchr(result,'\n')){
//printf("New line detected in result\n");
*nIndex = '\0';
}
val2 = atoi(result);
char dec = decode(val1,val2);
fprintf(out,"%c",dec);
}else{
val1 = atoi(result);
}
result = strtok( NULL, delims );
index++;
}
//printf (line);
}
fprintf(out, "]\n");
fclose(f);
fclose(out);
}
and my Raw data are
3596 1598 574 298 574 1166
572 301 603 268 576 295
573 298 600 271 610 260
577 295 572 299 573 298
573 299 603 268 577 1164
574 298 574 296 573 299
543 329 575 295 571 301
573 298 569 1173 576 1165
546 1197 662 184 636 261
544 1198 600 271 573 299
573 297 574 297 544 328
605 266 573 299 544 326
573 298 605 266 575 296
576 296 543 327 575 296
604 268 575 297 515 356
599 272 572 298 601 271
571 299 574 301 573 295
576 295 573 279 561 329
545 325 546 325 573 300
573 297 573 1169 572 1170
574 298 544 327 575 296
547 325 511 359 603 76167
3599 1625 548 322 553 1189
552 321 523 348 550 321
551 320 517 354 574 297
551 320 551 321 577 293
547 325 550 321 521 1219
525 348 552 319 550 321
549 322 552 320 549 322
550 321 548 1193 551 1191
584 1159 518 353 549 322
580 1170 546 317 551 321
552 319 579 292 551 320
552 320 551 320 553 318
549 322 579 292 547 324
550 321 555 317 550 320
581 1160 587 286 543 1198
552 1190 552 1191 550 321
551 321 581 290 547 324
549 322 550 321 548 1193
552 1191 550 319 583 292
550 320 576 295 579 292
551 320 519 353 551 319
548 323 553 1189 522 1220
550 1192 550 1192 551 1192
523 1219 551 1191 451 1291
522 350 550 321 553 318
548 323 555 316 551 320
553 319 552 319 554 316
584 300 566 294 550 320
552 319 549 322 550 321
553 321 552 317 549 321
550 1192 523 1219 550 1192
558 314 549 322 552 319
551 321 552 318 552 320
551 320 549 322 551 320
550 1192 548 1194 550 1192
551 320 613 258 526 346
554 319 549 322 522 348
576 294 522 350 522 348
555 317 523 348 552 319
552 319 550 321 548 323
552 319 580 1161 551 322
553 318 551 320 549 322
608 263 582 289 525 1216
550 322 521 350 552 320
551 320 552 319 549 322
581 290 551 321 550 320
552 319 555 317 523 348
548 324 551 319 546 325
551 321 479 391 572 1169
551 1192 554 1188 555 1188
551 321 549 1191 557 1187
551
and i got
[1�11111111111�1111111��#11#111111111111111111111111111111��11111�[1
11111111111+1111111##�11�11111111111111�1###111111##111111111
,###+#s111111111111111111#+#111111111###1111111111111111�111111(11111111111111111�#
please help me, thank you!

Answer 1

I am not used to playing with IR, but ...
If you want to use lirc you should configure it : http://lirc.org/html/configuration-guide.html.
You do not need to develop a specific utility to decode data.
You can use mode2 to get output form driver http://www.lirc.org/html/mode2.html
mode2 --driver default --device /dev/lirc0
Using driver default on device /dev/lirc0
Trying device: /dev/lirc0
Using device: /dev/lirc0
pulse 2750
space 800
pulse 500
space 350
pulse 550
space 350
pulse 550
Then lircd.conf is used to map data to key http://www.lirc.org/html/lircd.conf.html and with irw you get the result :
$ irw
000000037ff07bef 00 KEY_VOLUMEUP Acer_Aspire_6530G_MCE
000000037ff07bef 01 KEY_VOLUMEUP Acer_Aspire_6530G_MCE
000000037ff07bdd 00 KEY_ENTER Acer_Aspire_6530G_MCE
000000037ff07bdd 02 KEY_ENTER Acer_Aspire_6530G_MCE

Answer 2

It looks like you may be reading a remote intended for a Mitsubishi air conditioning system. Unlike most remotes, which just send a short signal corresponding to the button pressed and rely on the device being controlled to remember its previous state, Mitsubishi decided to transmit the entire desired state of the machine -- all the mode, fan, vane, and other settings get sent Every Time, as an 18-byte data block with checksum (which the remote then repeats once, as insurance against optical noise).
If you websearch "Mitsubishi minisplit IR protocol", you'll find some pages where people have at least partially analyzed this protocol.
This isn't the kind of approach LIRC's higher-level tools were designed to handle. You can still use the LIRC drivers, but they have to be accessed in "raw" mode and separate tools are used to interpret incoming signal or generate outgoing signal.
Searching Github finds libraries/tools others have written to work with this protocol. I haven't found one in a language I actually like working with, though, so I'm assuming I'm going to have to access the LIRC api calls to read/write the data and interpret/generate it myself.
RELATED: If you're using the ir-ctl program to do basic "raw" reading and writing while you test your hardware, be aware that ir-ctl's transmit mode has a line-length limit which this protocol sometimes exceeds if you put it all on a single line of text. The workaround is to insert line breaks every so often, so no single line of the input exceeds that hardcoded limit. (Yes, I've filed a bug report.)