Invalid signal disables RC decoding ability permanently

[hazarkarabay]

Hi,

I'm using IRLib2 for RC6 (RC6-6-32 [MCE Remote] to be exact) decoding. When it works, it works beautifully, so first of all thanks for the hard work!

I have a CCFL desk lamp which have ability to break IR decoding. When it's first starting up, it can generate some garbage on my TSOP38238's output (checked with a scope). Sometimes, this garbage signal can completely break IRLib2's decoding ability. When this issue occurs, for the rest of the session I can't receive any IR commands; only a power cycle / reset restores functionality.

Test sketch:

/* Includes */
#include <avr/wdt.h>
#include <IRLibRecv.h>
#include <IRLibDecodeBase.h>
#include <IRLib_P04_RC6.h>
#include <IRLibCombo.h>

/* Library init */
IRrecv myReceiver(2);  // pin number for the IR receiver
IRdecode myDecoder;

void setup() {
  // Setup WDT
  wdt_enable(WDTO_2S);
  myReceiver.enableIRIn(); // Start the receiver
  Serial.begin(115200);
}

void loop() {
  // IR receive and decode stuff
  if (myReceiver.getResults()) {
    if (myDecoder.decode()) {
      Serial.println(myDecoder.value);
    }

    myReceiver.enableIRIn();
    myDecoder.dumpResults(true);
  }
}

Output when this issue happens:

Decoded Unknown(0): Value:0 Adrs:0 (0 bits) 
Raw samples(100): Gap:1838
  Head: m14546  s1838
0:m6354 s-22738 1:m-26414 s-14546        2:m22738 s1838 3:m-26414 s-6354         
4:m30930 s1838  5:m-1838 s-6354      6:m-18222 s18222   7:m-26414 s-14546        
8:m-18222 s-30930   9:m-18222 s-6354         10:m30930 s-6354   11:m30930 s1838      
12:m6354 s-22738    13:m6354 s-6354      14:m22738 s18222   15:m-1838 s-30930        

16:m-1838 s-30930   17:m-10030 s-14546       18:m-10030 s26414  19:m-18222 s-30930       
20:m-1838 s-22738   21:m-18222 s-30930       22:m30930 s26414   23:m-18222 s1838         
24:m-10030 s26414   25:m-26414 s-22738       26:m14546 s-6354   27:m30930 s-22738        
28:m14546 s-14546   29:m-26414 s1838         30:m30930 s1838    31:m30930 s10030         

32:m6354 s18222 33:m14546 s18222         34:m-18222 s-30930 35:m30930 s1838      
36:m-26414 s-6354   37:m14546 s26414         38:m-10030 s-14546 39:m30930 s-30930        
40:m30930 s-22738   41:m-26414 s18222        42:m-10030 s-6354  43:m-18222 s26414        
44:m22738 s1838 45:m30930 s18222         46:m-26414 s1838   47:m-10030 s26414        

48:m-26414
Extent=4294842578
Mark  min:-26414     max:30930
Space min:1838   max:26414

Decoded Unknown(0): Value:0 Adrs:0 (0 bits) 
Raw samples(100): Gap:26414
  Head: m6354  s26414
0:m-10030 s-22738   1:m-10030 s-6354         2:m22738 s26414    3:m-10030 s10030         
4:m-26414 s26414    5:m-26414 s10030         6:m6354 s-6354 7:m-10030 s-6354         
8:m6354 s26414  9:m6354 s10030       10:m-26414 s10030  11:m-26414 s26414        
12:m-10030 s-22738  13:m-10030 s10030        14:m22738 s-6354   15:m-26414 s26414        

16:m-26414 s26414   17:m22738 s-6354         18:m22738 s10030   19:m6354 s26414      
20:m-26414 s-22738  21:m6354 s26414      22:m-26414 s10030  23:m6354 s26414      
24:m22738 s10030    25:m-10030 s-22738       26:m6354 s10030    27:m-26414 s-22738       
28:m6354 s-6354 29:m-10030 s26414        30:m-26414 s26414  31:m-26414 s-22738       

32:m-10030 s-6354   33:m6354 s-6354      34:m6354 s26414    35:m-26414 s26414        
36:m-10030 s10030   37:m6354 s10030      38:m22738 s-6354   39:m-26414 s26414        
40:m-26414 s-22738  41:m-10030 s-6354        42:m22738 s10030   43:m6354 s10030      
44:m22738 s26414    45:m-26414 s-6354        46:m-10030 s26414  47:m22738 s10030         

48:m-10030
Extent=121042
Mark  min:-26414     max:22738
Space min:10030  max:26414

Decoded Unknown(0): Value:0 Adrs:0 (0 bits) 
Raw samples(100): Gap:10030
  Head: m55506  s10030
0:m22738 s-22738    1:m22738 s10030      2:m22738 s10030    3:m22738 s-22738         
4:m-10030 s10030    5:m-10030 s-22738        6:m-10030 s10030   7:m22738 s10030      
8:m-10030 s10030    9:m-10030 s-22738        10:m-10030 s-22738 11:m-10030 s10030        
12:m22738 s-22738   13:m22738 s-22738        14:m22738 s10030   15:m-10030 s10030        

16:m-10030 s10030   17:m22738 s10030         18:m22738 s-22738  19:m-10030 s10030        
20:m-10030 s-22738  21:m-10030 s10030        22:m-10030 s-22738 23:m-10030 s10030        
24:m22738 s-22738   25:m22738 s-22738        26:m-10030 s-22738 27:m-10030 s-22738       
28:m-10030 s10030   29:m22738 s10030         30:m-10030 s10030  31:m-10030 s-22738       

32:m22738 s10030    33:m-10030 s10030        34:m-10030 s10030  35:m-10030 s10030        
36:m22738 s-22738   37:m-10030 s-22738       38:m22738 s10030   39:m-10030 s10030        
40:m-10030 s-22738  41:m22738 s10030         42:m22738 s-22738  43:m-10030 s-22738       
44:m22738 s10030    45:m-10030 s10030        46:m22738 s10030   47:m22738 s-22738        

48:m22738
Extent=22738
Mark  min:-10030     max:22738
Space min:10030  max:10030

Decoded Unknown(0): Value:0 Adrs:0 (0 bits) 
Raw samples(100): Gap:42798
  Head: m22738  s42798
0:m22738 s-22738    1:m22738 s-22738         2:m22738 s-22738   3:m22738 s-22738         
4:m22738 s-22738    5:m22738 s-22738         6:m22738 s-22738   7:m22738 s-22738         
8:m22738 s-22738    9:m22738 s-22738         10:m22738 s-22738  11:m22738 s-22738        
12:m22738 s-22738   13:m22738 s-22738        14:m22738 s-22738  15:m22738 s-22738        

16:m22738 s-22738   17:m22738 s-22738        18:m22738 s-22738  19:m22738 s-22738        
20:m22738 s-22738   21:m22738 s-22738        22:m22738 s-22738  23:m22738 s-22738        
24:m22738 s-22738   25:m22738 s-22738        26:m22738 s-22738  27:m22738 s-22738        
28:m22738 s-22738   29:m22738 s-22738        30:m22738 s-22738  31:m22738 s-22738        

32:m22738 s-22738   33:m22738 s-22738        34:m22738 s-22738  35:m22738 s-22738        
36:m22738 s-22738   37:m22738 s-22738        38:m22738 s-22738  39:m22738 s-22738        
40:m22738 s-22738   41:m22738 s-22738        42:m22738 s-22738  43:m22738 s-22738        
44:m22738 s-22738   45:m22738 s-22738        46:m22738 s-22738  47:m22738 s-22738        

48:m22738
Extent=22738
Mark  min:22738  max:22738
Space min:32767  max:0

Decoded Unknown(0): Value:0 Adrs:0 (0 bits) 
Raw samples(100): Gap:42798
  Head: m22738  s42798
0:m22738 s-22738    1:m22738 s-22738         2:m22738 s-22738   3:m22738 s-22738         
4:m22738 s-22738    5:m22738 s-22738         6:m22738 s-22738   7:m22738 s-22738         
8:m22738 s-22738    9:m22738 s-22738         10:m22738 s-22738  11:m22738 s-22738        
12:m22738 s-22738   13:m22738 s-22738        14:m22738 s-22738  15:m22738 s-22738        

16:m22738 s-22738   17:m22738 s-22738        18:m22738 s-22738  19:m22738 s-22738        
20:m22738 s-22738   21:m22738 s-22738        22:m22738 s-22738  23:m22738 s-22738        
24:m22738 s-22738   25:m22738 s-22738        26:m22738 s-22738  27:m22738 s-22738        
28:m22738 s-22738   29:m22738 s-22738        30:m22738 s-22738  31:m22738 s-22738        

32:m22738 s-22738   33:m22738 s-22738        34:m22738 s-22738  35:m22738 s-22738        
36:m22738 s-22738   37:m22738 s-22738        38:m22738 s-22738  39:m22738 s-22738        
40:m22738 s-22738   41:m22738 s-22738        42:m22738 s-22738  43:m22738 s-22738        
44:m22738 s-22738   45:m22738 s-22738        46:m22738 s-22738  47:m22738 s-22738        

48:m22738
Extent=22738
Mark  min:22738  max:22738
Space min:32767  max:0

Decoded Unknown(0): Value:0 Adrs:0 (0 bits) 
Raw samples(100): Gap:42798
  Head: m22738  s42798
0:m22738 s-22738    1:m22738 s-22738         2:m22738 s-22738   3:m22738 s-22738         
4:m22738 s-22738    5:m22738 s-22738         6:m22738 s-22738   7:m22738 s-22738         
8:m22738 s-22738    9:m22738 s-22738         10:m22738 s-22738  11:m22738 s-22738        
12:m22738 s-22738   13:m22738 s-22738        14:m22738 s-22738  15:m22738 s-22738        

16:m22738 s-22738   17:m22738 s-22738        18:m22738 s-22738  19:m22738 s-22738        
20:m22738 s-22738   21:m22738 s-22738        22:m22738 s-22738  23:m22738 s-22738        
24:m22738 s-22738   25:m22738 s-22738        26:m22738 s-22738  27:m22738 s-22738        
28:m22738 s-22738   29:m22738 s-22738        30:m22738 s-22738  31:m22738 s-22738        

32:m22738 s-22738   33:m22738 s-22738        34:m22738 s-22738  35:m22738 s-22738        
36:m22738 s-22738   37:m22738 s-22738        38:m22738 s-22738  39:m22738 s-22738        
40:m22738 s-22738   41:m22738 s-22738        42:m22738 s-22738  43:m22738 s-22738        
44:m22738 s-22738   45:m22738 s-22738        46:m22738 s-22738  47:m22738 s-22738        

48:m22738
Extent=22738
Mark  min:22738  max:22738
Space min:32767  max:0

... (repeating last block indefinitely, only a power cycle / reset restores functionality at this point)

Note that when this occurs, turning the said lamp off (or toggling) doesn't change/fix this situation. So this is not a simple interference issue. Also I checked that is no electrical / EMI interference issue which directly affects the AVR or other board-level components and when issue happens rest of the code works normally, only IR decoding is broken.

Can you provide some pointers where to look at? Thanks.

[michaldie]

I see a similar issue when I send a signal from my DENON remote RC1161 the first dump output looks reasonable (unknown) but it never stops thereafter old IRremote does give me : Received unknown code, saving as raw m3300 s1800 m300 s500 m400 s450 m350 s1350 m300 s500 m350 s1350 m350 s500 m350 s1300 m350 s500 m350 s500 m350 s1300 m350 s500 m350 s500 m350 s1350 m350 s1300 m350 s500 m350 s500 m350 s450 m350 s500 m350 s500 m350 s500 m300 s500 m350 s1350 m350 s500 m350 s500 m300 s1350 m350 s500 m350 s500 m300 s500 m350 s1350 m350 s1350 m350 s450 m350 s1350 m350 s500 m350 s1300 m350 s500 m350 s500 m300 s500 m400 s450 m350 s500 m350 s500 m350 s1300 m400 s1300 m350 s500 m300 s500 m350 s1350 m350 s500 m300 s500 m350 s1350 m350

similar to Hazar, I am getting an endless stream of dump when triggering the effect. I wonder if some buffer is overrun ?

Decoded Unknown(0): Value:0 Adrs:0 (0 bits) Raw samples(100): Gap:49428 Head: m3350 s1700 0:m400 s450 1:m400 s450 2:m350 s1300 3:m400 s450
4:m400 s1250 5:m400 s450 6:m450 s1250 7:m400 s400
8:m400 s450 9:m450 s1250 10:m400 s450 11:m400 s400
12:m400 s1300 13:m400 s1250 14:m400 s450 15:m400 s450

16:m400 s450 17:m350 s500 18:m350 s450 19:m400 s450
20:m400 s450 21:m400 s1250 22:m400 s450 23:m400 s450
24:m400 s1250 25:m450 s400 26:m400 s450 27:m400 s450
28:m400 s1250 29:m400 s1300 30:m400 s450 31:m400 s1250

32:m400 s450 33:m400 s1300 34:m350 s450 35:m450 s400
36:m400 s450 37:m400 s450 38:m400 s400 39:m400 s450
40:m400 s1300 41:m400 s1250 42:m400 s450 43:m400 s450
44:m400 s1250 45:m400 s450 46:m400 s450 47:m400 s1250

48:m400 Extent=59100 Mark min:350 max:450 Space min:400 max:1300

Decoded Unknown(0): Value:0 Adrs:0 (0 bits) Raw samples(100): Gap:46618 Head: m36378 s19514 0:m19950 s22550 1:m19950 s22550 2:m17450 s-486 3:m19950 s22550
4:m19950 s-2986 5:m19950 s22550 6:m22450 s-2986 7:m19950 s20050
8:m19950 s22550 9:m22450 s-2986 10:m19950 s22550 11:m19950 s20050
12:m19950 s-486 13:m19950 s-2986 14:m19950 s22550 15:m19950 s22550

16:m19950 s22550 17:m17450 s25050 18:m17450 s22550 19:m19950 s22550
20:m19950 s22550 21:m19950 s-2986 22:m19950 s22550 23:m19950 s22550
24:m19950 s-2986 25:m22450 s20050 26:m19950 s22550 27:m19950 s22550
28:m19950 s-2986 29:m19950 s-486 30:m19950 s22550 31:m19950 s-2986

32:m19950 s22550 33:m19950 s-486 34:m17450 s22550 35:m22450 s20050
36:m19950 s22550 37:m19950 s22550 38:m19950 s20050 39:m19950 s22550
40:m19950 s-486 41:m19950 s-2986 42:m19950 s22550 43:m19950 s22550
44:m19950 s-2986 45:m19950 s22550 46:m19950 s22550 47:m19950 s-2986

48:m19950 Extent=1709766 Mark min:17450 max:22450 Space min:20050 max:25050

....

[michaldie]

going down the buffer trail - my lockup by DENON was fixed by increasing the buffer size .. 102 instead of 100 did the job... IRLib2/IRLibGlobals.h:27:#define RECV_BUF_LENGTH 102

however it would seem anything that floods the buffer when using IRLibRecv.h would be able to cause this -

[michaldie]

it seems it is IRLibRecv that struggles with any buffer overrun. IRLibRecvPCI does not show the same issue.