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@cnlohr
Last active October 17, 2024 00:04
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HTC Vive Watchman Hacking Codes!
So, the way this goes is I post my AVR code, then I post what the HTC Vive does.
The output is: POST 0: (# of bytes) (IMU Timecode MSBs) (All raw light data)
(All raw light data ends with [3 bytes, LSB timecode] [OTA CRC (probably ignore)])
Events (TIME): (LED CODE 1)/(TIME CODE 1/TIMECODE 2)/(LED CODE 2)/(TIME CODE 3/TIMECODE 4)...
//NOTICE: The funky encoding of the numbers, and the fact that paramters are read from the end of the data going forward.
//We know we're done when the # of parameters read is (# of bytes left*2)-1
tikingfritsthecat suggests reading: https://en.wikipedia.org/wiki/Variable-length_quantity
For all of the following we will use _delay_ms(10) between messages.
PARAMETER FIELDS are encoded, read from end going forward. If MSB is 1 (i.e. 0x80) it is done! If not, then need to read next byte.
// First look at 0x04. There will be another byte because it is less than
// 128!
// 0x04<<7 = 0x200
// Because 0x81 is >= 128, it's a terminator.
// 0x200 | 0x81 = 0x281 << The actual value
//
marker = 40;
do{ PORTB = LED48;
marker--; PORTB = 0; } while( marker );
_delay_us(10);
marker = 40;
do{ PORTB = LED50;
marker--; PORTB = 0; } while( marker );
_delay_us(10);
marker = 40;
do{ PORTB = LED40;
marker--; PORTB = 0; } while( marker );
Produces:
POST 0: 16 (f62d) - 40 50 48 b0 05 a2 02 c1 05 c7 03 f1 03 65 9b 2f 80 03 2b 58
Events (-164652187): 48/( 688/ 290)50/( 705/ 455)40/( 497/ -1)
POST 0: 16 (f633) - 40 50 48 b0 05 a2 02 c2 05 cb 03 ec 03 63 f4 33 28 40 ed c5
Events (-164367261): 48/( 688/ 290)50/( 706/ 459)40/( 492/ -1)
POST 0: 16 (f636) - 40 50 48 b2 05 a3 02 c3 05 c5 03 f5 03 57 4e 38 d2 2e c9 30
Events (-164082089): 48/( 690/ 291)50/( 707/ 453)40/( 501/ -1)
POST 0: 16 (f63b) - 40 50 48 b2 05 a3 02 c4 05 c6 03 f4 03 c6 a8 3c fe bd ca c1
Events (-163796794): 48/( 690/ 291)50/( 708/ 454)40/( 500/ -1)
POST 0: 16 (f63e) - 40 50 48 b1 05 a3 02 c3 05 c1 03 f8 03 40 02 41 fd 6d e0 08
Events (-163511744): 48/( 689/ 291)50/( 707/ 449)40/( 504/ -1)
marker = 40; //Length of time for following
do{ PORTB = LED48;
marker--; PORTB = 0; } while( marker );
vvvvvvvv
Events (-890299908): 48/( 683/ -1)
POST 0: 6 (caf1) - 48 ac 05 bd 6b f3 9e 3b ab c6
Events (-890016835): 48/( 684/ -1)
POST 0: 6 (caf6) - 48 ac 05 f2 bd f7 dc 46 0e 7f
Events (-889733646): 48/( 684/ -1)
POST 0: 6 (caf9) - 48 ac 05 73 10 fc 7a 78 6d 93
Events (-889450381): 48/( 684/ -1)
marker = 40; //Length of time for following
do{ PORTB = LED48;
marker--; PORTB = 0; } while( marker );
marker = 40; //Length of time for following
do{ PORTB = LED50 | LED48;
marker--; PORTB = 0; } while( marker );
marker = 40; //Length of time for following
do{ PORTB = LED48;
marker--; PORTB = 0; } while( marker );
PRODUCES:::::
POST 0: 11 (b03d) - 4a 50 b8 05 c1 05 b4 05 b6 b1 3d e8 dc 86 2e
Events (-1338134090): 50/( 696/ 705)4a/( 692/ -1)
POST 0: 11 (b040) - 4a 50 b6 05 c0 05 b2 05 bf 09 42 5f 9b a8 e3
Events (-1337849409): 50/( 694/ 704)4a/( 690/ -1)
POST 0: 11 (b046) - 4a 50 b7 05 c0 05 b1 05 1d 61 46 9e d5 b2 5b
Events (-1337564899): 50/( 695/ 704)4a/( 689/ -1)
marker = 40; //Length of time for following
do{ PORTB = LED50;
marker--; PORTB = 0; } while( marker );
marker = 40; //Length of time for following
do{ PORTB = LED50 | LED48;
marker--; PORTB = 0; } while( marker );
marker = 40; //Length of time for following
do{ PORTB = LED50;
marker--; PORTB = 0; } while( marker );
PRODUCES:
POST 0: 11 (f21f) - 52 48 cb 05 ac 05 c1 05 21 5b 20 fe 55 89 00
Events (-232760543): 48/( 715/ 684)52/( 705/ -1)
POST 0: 11 (f222) - 52 48 cb 05 ac 05 c0 05 13 b2 24 2b 65 ee 99
Events (-232476141): 48/( 715/ 684)52/( 704/ -1)
POST 0: 11 (f228) - 52 48 cb 05 ab 05 c1 05 ee 08 29 56 7b 9e 70
Events (-232191762): 48/( 715/ 683)52/( 705/ -1)
POST 0: 11 (f22b) - 52 48 ca 05 ab 05 c0 05 97 5f 2d c4 01 c6 5c
Events (-231907433): 48/( 714/ 683)52/( 704/ -1)
marker = 255; //Length of time for following
for( k = 0; k < 12; k++ )
do{ PORTB = LED50;
marker--; PORTB = 0; } while( marker );
POST 0: 7 (6ea8) - 50 c5 7b 03 f7 a7 a0 f1 12 65 81
Events (1856022519): 50/(64965/ -1)
POST 0: 7 (6eae) - 50 c5 7b 03 81 f3 a5 37 cd 97 f1
Events (1856369537): 50/(64965/ -1)
BUT
marker = 255; //Length of time for following
for( k = 0; k < 13; k++ )
do{ PORTB = LED50;
marker--; PORTB = 0; } while( marker );
PRODUCES NOTHING AT ALL!!!!
Looks like maximum for timing is 65536.
marker = 80; //Length of time for following
do{ PORTB = LED50;
marker--; PORTB = 0; } while( marker );
marker = 90; //Length of time for following
do{ PORTB = LED50 | LED48;
marker--; PORTB = 0; } while( marker );
marker = 100; //Length of time for following
do{ PORTB = LED50;
marker--; PORTB = 0; } while( marker );
produces;
POST 0: 12 (e16d) - 48 50 fe 24 cd 25 11 91 0c 6a 24 6f b8 5a fd 69
Events (-512809878): 50/( 4734/283341)48/( 1553/ -1)
POST 0: 12 (e172) - 48 50 f7 24 b2 26 11 93 0c 88 84 73 8c ac ad 52
Events (-512523128): 50/( 4727/283442)48/( 1555/ -1)
POST 0: 12 (e175) - 48 50 ff 24 b3 26 11 8f 0c a6 e4 77 94 7f a1 10
Events (-512236378): 50/( 4735/283443)48/( 1551/ -1)
POST 0: 12 (e17b) - 48 50 f4 24 8c 24 11 91 0c 9a 43 7c 70 a6 51 63
Events (-511949926): 50/( 4724/283148)48/( 1553/ -1)
POST 0: 12 (e17e) - 48 50 f7 24 84 27 11 90 0c 06 a4 80 ab 7b 91 b2
Events (-511663098): 50/( 4727/283524)48/( 1552/ -1)
NOTE PARAMETER 2 IS NOT BETWEEN 0 and 65535 (it's value (above 65536) is 4.)
marker = 30; //Length of time for following
do{ PORTB = LED50;
marker--; PORTB = 0; } while( marker );
marker = 20; //Length of time for following
do{ PORTB = LED50 | LED48;
marker--; PORTB = 0; } while( marker );
marker = 10; //Length of time for following
do{ PORTB = LED50;
marker--; PORTB = 0; } while( marker );
Produces:
POST 0: 11 (632a) - 52 48 9f 04 c3 02 ba 01 58 40 2d 7a 4a 80 67
Events (1663909976): 48/( 543/ 323)52/( 186/ -1)
POST 0: 11 (6330) - 52 48 9f 04 c5 02 ba 01 16 92 31 ef 8e 7b 75
Events (1664193046): 48/( 543/ 325)52/( 186/ -1)
POST 0: 11 (6333) - 52 48 9f 04 c4 02 b9 01 87 e4 35 b1 e2 cf 45
Events (1664476295): 48/( 543/ 324)52/( 185/ -1)
...wat??
marker = 30; //Length of time for following
do{ PORTB = LED40;
marker--; PORTB = 0; } while( marker );
marker = 20; //Length of time for following
do{ PORTB = LED40 | LED48;
marker--; PORTB = 0; } while( marker );
marker = 10; //Length of time for following
do{ PORTB = LED40;
marker--; PORTB = 0; } while( marker );
Events (2081688601): 48/( 330/ 323)42/( 153/ -1)
POST 0: 11 (7c17) - 42 48 c8 02 c5 02 98 01 a0 5f 18 b4 65 3a 41
Events (2081972128): 48/( 328/ 325)42/( 152/ -1)
POST 0: 11 (7c1a) - 42 48 cb 02 c3 02 99 01 05 b3 1c 0b 5a 16 37
Events (2082255621): 48/( 331/ 323)42/( 153/ -1)
#define DO_MARKER( time, LEDS ) \
marker = time; do { PORTB = LEDs; marker--; PORTB = 0; } while( marker );
DO_MARKER( 30, LED48 );
DO_MARKER( 20, LED48|LED40 );
DO_MARKER( 10, LED48 );
POST 0: 11 (7bb4) - 4a 40 bb 04 9a 02 bc 01 cf 0c b6 56 5c 4d 87
Events (2075528399): 40/( 571/ 282)4a/( 188/ -1)
DO_MARKER( 30, LED48 );
DO_MARKER( 20, LED40|LED48 );
DO_MARKER( 10, LED40 );
Events ( 615414066): 49/( 676/ 188)41/( 158/ -1)
DO_MARKER( 30, LED48 );
_delay_us(50);
DO_MARKER( 70, LED40 );
Events (-1151761741): 48/( 512/ 1510)40/( 1115/ -1)
DO_MARKER( 30, LED48 );
DO_MARKER( 20, LED50|LED48 );
DO_MARKER( 10, LED50 );
Events (1259200831): 49/( 522/ 343)51/( 181/ -1)
DO_MARKER( 30, LED40 );
DO_MARKER( 20, LED50|LED40 );
DO_MARKER( 10, LED50 );
POST 0: 11 (a3b6) - 51 41 b5 03 c5 02 c9 01 8e 3f b8 86 85 bb b7
Events (-1548206194): 41/( 437/ 325)51/( 201/ -1)
DO_MARKER( 20, LED40 );
DO_MARKER( 20, LED50|LED40 );
DO_MARKER( 20, LED50 );
POST 0: 11 (dce8) - 51 41 86 02 c4 02 f8 02 90 94 eb b9 24 5b 63
Events (-588540784): 41/( 262/ 324)51/( 376/ -1)
DO_MARKER( 21, LED40 );
DO_MARKER( 21, LED50|LED40 );
DO_MARKER( 21, LED50 );
POST 0: 11 (61e6) - 51 41 93 02 d4 02 89 03 8d da e6 b2 12 4b 0e
Events (1642519181): 41/( 275/ 340)51/( 393/ -1)
DO_MARKER( 22, LED40 );
DO_MARKER( 22, LED50|LED40 );
DO_MARKER( 22, LED50 );
POST 0: 11 (a35b) - 51 41 9f 02 e7 02 99 03 2c f0 5d 5d f4 45 0d
Events (-1554124756): 41/( 287/ 359)51/( 409/ -1)
DO_MARKER( 8, LED40 );
DO_MARKER( 8, LED50|LED40 );
DO_MARKER( 8, LED50 );
Events (-220957990): 41/( 45/ 111)51/( 171/ -1)
DO_MARKER( 9, LED40 );
DO_MARKER( 9, LED50|LED40 );
DO_MARKER( 9, LED50 );
POST 0: 10 (3343) - 51 41 bf 81 01 bb 01 65 62 43 b6 8c d0 8e
Events ( 860054117): 41/( 63/ 129)51/( 187/ -1)
DO_MARKER( 9, LED50 );
DO_MARKER( 9, LED50|LED40 );
DO_MARKER( 9, LED40 );
POST 0: 11 (6cec) - 41 51 a8 01 9a 01 92 01 71 a6 ec 5f 50 40 67
Events (1827448433): 51/( 168/ 154)41/( 146/ -1)
DO_MARKER( 10, LED40 );
DO_MARKER( 20, LED48|LED40 );
DO_MARKER( 30, LED40 );
POST 0: 11 (0508) - 42 48 b2 01 c4 02 93 04 24 39 09 5a e4 5e af
Events ( 84490532): 48/( 178/ 324)42/( 531/ -1)
DO_MARKER( 10, LED40 );
DO_MARKER( 20, LED48|LED40 );
DO_MARKER( 10, LED40 );
POST 0: 11 (65ab) - 42 48 b1 01 c6 02 b3 01 f0 68 ae 3a 89 73 1e
Events (1705928944): 48/( 177/ 326)42/( 179/ -1)
DO_MARKER( 10, LED40 );
DO_MARKER( 40, LED48|LED40 );
DO_MARKER( 80, LED40 );
POST 0: 11 (afe8) - 42 48 af 01 90 05 85 0b 65 cc e7 3b c6 92 4f
Events (-1343763355): 48/( 175/ 656)42/( 1413/ -1)
DO_MARKER( 10, LED40 );
DO_MARKER( 40, LED50|LED40 );
DO_MARKER( 80, LED50 );
POST 0: 11 (257b) - 51 41 94 01 ad 05 8d 0b 48 43 7e 47 ae ab e6
Events ( 629031752): 41/( 148/ 685)51/( 1421/ -1)
POST 0: 11 (2581) - 51 41 95 01 ad 05 8e 0b 1b 9b 82 d6 9e 4c b5
Events ( 629316379): 41/( 149/ 685)51/( 1422/ -1)
DO_MARKER( 10, LED40 );
DO_MARKER( 40, LED50|LED40 );
DO_MARKER( 80, LED40 );
POST 0: 11 (963b) - 42 50 95 01 c2 05 ef 0a 1b 1f 3b cc 8e 19 e9
Events (-1774510309): 50/( 149/ 706)42/( 1391/ -1)
POST 0: 11 (963e) - 42 50 95 01 c1 05 ee 0a 8c 76 3f 32 fe 46 87
Events (-1774225780): 50/( 149/ 705)42/( 1390/ -1)
DO_MARKER( 40, LED40 );
DO_MARKER( 40, LED50|LED40 );
DO_MARKER( 40, LED40 );
DO_MARKER( 40, LED50|LED40 );
DO_MARKER( 40, LED40 );
DO_MARKER( 40, LED50|LED40 );
DO_MARKER( 40, LED40 );
Events (-415661420): 40/( 4885/282886)50/( 705/ 700)50/( 705/ 706)50/( 700/ -1)
POST 0: 22 (e73d) - 50 50 50 40 94 26 b0 23 11 c2 05 bd 05 c1 05 c4 05 bd 05 b8 e4 3d 20 92 0c ca
Events (-415374152): 40/( 4884/283056)50/( 706/ 701)50/( 705/ 708)50/( 701/ -1)
POST 0: 22 (e740) - 50 50 50 40 9c 26 a6 23 11 c1 05 be 05 c1 05 c4 05 bc 05 d3 46 42 1b 23 6d ec
Events (-415086893): 40/( 4892/283046)50/( 705/ 702)50/( 705/ 708)50/( 700/ -1)
POST 0: 22 (e746) - 50 50 50 40 9c 26 db 21 11 c2 05 bc 05 c1 05 c1 05 bb 05 1e a8 46 88 30 f0 fc
Events (-414799842): 40/( 4892/282843)50/( 706/ 700)50/( 705/ 705)50/( 699/ -1)
WWOOHHH LOOK AT THE BIG NUBMERR ^^^^^
DO_MARKER( 40, LED40 );
DO_MARKER( 40, LED50|LED40 );
DO_MARKER( 40, LED40 );
DO_MARKER( 40, LED50|LED40 );
DO_MARKER( 40, LED40 );
POST 0: 17 (35a1) - 50 50 40 93 1b ab 23 11 c1 05 bd 05 c1 05 70 9d a2 67 b3 6a ce
Events ( 899849584): 40/( 3475/283051)50/( 705/ 701)50/( 705/ -1)
^^^ Big numberrrrr
DO_MARKER( 40, LED48 );
DO_MARKER( 40, LED50|LED48 );
DO_MARKER( 40, LED50 );
POST 0: 11 (3ee8) - 51 49 a6 05 ac 05 d1 05 6f 51 ea 6d 4c 11 df
Events (1055543663): 49/( 678/ 684)51/( 721/ -1)
DO_MARKER( 40, LED48 );
DO_MARKER( 40, LED50|LED48 );
DO_MARKER( 40, LED48 );
DO_MARKER( 40, LED50|LED48 );
DO_MARKER( 40, LED48 );
DO_MARKER( 40, LED50|LED48 );
DO_MARKER( 40, LED48 );
POST 0: 22 (d156) - 50 50 50 48 8b 26 bb 22 11 be 05 bc 05 bf 05 c2 05 bb 05 04 29 57 89 58 68 fe
Events (-782817020): 48/( 4875/282939)50/( 702/ 700)50/( 703/ 706)50/( 699/ -1)
DO_MARKER( 40, LED48 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED48 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED48 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED48 );
POST 0: 22 (97f3) - 40 40 40 48 a1 26 fe 21 11 bb 05 be 05 be 05 c2 05 bb 05 35 5f f5 0a fe 8c 23
Events (-1745526987): 48/( 4897/282878)40/( 699/ 702)40/( 702/ 706)40/( 699/ -1)
DO_MARKER( 40, LED48 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED48 );
DO_MARKER( 40, LED50|LED48 );
DO_MARKER( 40, LED48 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED48 );
Events (-573114289): 48/( 4898/282829)40/( 699/ 707)50/( 697/ 715)40/( 694/ -1)
POST 0: 22 (ddd9) - 40 50 40 48 a2 26 82 21 11 bb 05 c1 05 b9 05 ca 05 b6 05 37 59 db 02 ba 5b c3
Events (-572827337): 48/( 4898/282754)40/( 699/ 705)50/( 697/ 714)40/( 694/ -1)
DO_MARKER( 40, LED48 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED48 );
DO_MARKER( 40, LED50|LED48 );
DO_MARKER( 40, LED48 );
POST 0: 17 (3927) - 50 40 48 a1 1b a4 1f 11 bb 05 c1 05 ba 05 7a 99 27 2b f0 8a d0
Events ( 958896506): 48/( 3489/282532)40/( 699/ 705)50/( 698/ -1)
DO_MARKER( 40, LED48 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED48 );
_delay_us(10);
DO_MARKER( 40, LED48 );
DO_MARKER( 40, LED50|LED48 );
DO_MARKER( 40, LED48 );
Events (1353710091): 40/( 695/ 699)4a/( 689/ 275)50/( 727/ 697)4a/( 690/ -1)
POST 0: 21 (50b2) - 4a 50 4a 40 b8 05 bc 05 b0 05 94 02 d7 05 ba 05 b2 05 14 59 b4 75 86 56 a5
Events (1353996564): 40/( 696/ 700)4a/( 688/ 276)50/( 727/ 698)4a/( 690/ -1)
POST 0: 21 (50b8) - 4a 50 4a 40 b8 05 bb 05 b2 05 93 02 d7 05 ba 05 b2 05 05 b9 b8 1b ea 08 c6
Events (1354283269): 40/( 696/ 699)4a/( 690/ 275)50/( 727/ 698)4a/( 690/ -1)
DO_MARKER( 40, LED48 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED40|LED48|LED50 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED48 );
POST 0: 17 (499b) - 42 50 48 9f 1b bd 1f 11 bf 05 bd 05 b9 05 e7 cd 9c 01 37 d9 f8
Events (1235013095): 48/( 3487/282557)50/( 703/ 701)42/( 697/ -1)
POST 0: 17 (499e) - 42 50 48 9f 1b 87 1f 11 c0 05 be 05 ba 05 5a 28 a1 60 5f db 06
Events (1235298394): 48/( 3487/282503)50/( 704/ 702)42/( 698/ -1)
DO_MARKER( 40, LED40 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED40|LED48|LED50 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED40 );
POST 0: 17 (eccf) - 4a 50 40 b2 1b c8 20 11 af 05 bd 05 ad 05 9a c7 d1 1a 2b 09 9b
Events (-321796198): 40/( 3506/282696)50/( 687/ 701)4a/( 685/ -1)
DO_MARKER( 40, LED40 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED40|LED48|LED50 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED40|LED48|LED50 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED40 );
POST 0: 22 (91ed) - 50 50 42 48 cf 05 92 1b c4 05 bb 22 11 bd 05 b7 05 be 05 b4 6e ed 89 d4 56 85
Events (-1846710604): 48/( 719/ 3474)42/( 708/282939)50/( 701/ 695)50/( 702/ -1)
POST 0: 22 (91f0) - 50 50 42 48 ce 05 8d 1b c2 05 d3 21 11 be 05 b8 05 be 05 2b cd f1 66 d1 06 5b
Events (-1846424277): 48/( 718/ 3469)42/( 706/282835)50/( 702/ 696)50/( 702/ -1)
DO_MARKER( 40, LED40 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED40|LED48|LED50 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED40|LED48|LED50 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED40|LED48|LED50 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED40 );
POST 0: 22 (1ed9) - 50 50 42 48 cf 05 92 26 c2 05 bf 25 11 bf 05 ba 05 c0 05 80 85 da 46 01 54 29
Events ( 517637504): 48/( 719/ 4882)42/( 706/283327)50/( 703/ 698)50/( 704/ -1)
POST 2: 6 (1edc) - 50 ba 05 fa 8a da e6 b3 9b 6c
Events ( 517638906): 50/( 698/ -1)
DO_MARKER( 40, LED40 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED40|LED48|LED50 );
DO_MARKER( 40, LED40|LED48 );
DO_MARKER( 40, LED40|LED48|LED50 );
DO_MARKER( 40, LED40|LED50 ); <<<< Check this out!
DO_MARKER( 40, LED40 );
Events (-938793947): 40/( 4907/282843)50/( 688/ 703)4b/( 699/ 691)51/( 712/ -1)
POST 1: 22 (c80e) - 51 4b 50 40 b1 26 d8 21 11 b1 05 bf 05 ba 05 b3 05 c8 05 5d 85 0f 08 79 be 17
Events (-938506915): 40/( 4913/282840)50/( 689/ 703)4b/( 698/ 691)51/( 712/ -1)
POST 0: 22 (c811) - 51 4b 50 40 ad 26 b8 20 11 af 05 be 05 b9 05 b2 05 c6 05 ec e5 13 52 fa ff e6
Events (-938220052): 40/( 4909/282680)50/( 687/ 702)4b/( 697/ 690)51/( 710/ -1)
DO_MARKER( 10, LED40 );
DO_MARKER( 10, LED40|LED48 );
DO_MARKER( 10, LED40|LED48|LED50 );
DO_MARKER( 10, LED40|LED48 );
DO_MARKER( 10, LED40|LED48|LED50 );
DO_MARKER( 10, LED40|LED50 );
DO_MARKER( 10, LED40 ); *** Maybe something is not being seen?
POST 0: 20 (b544) - 46 51 4b 50 bf 01 a0 01 b5 01 fb d2 01 bf 01 ac 01 f8 37 46 8c 97 9c 84
Events (-1253689352): 50/( 191/ 160)4b/( 181/ 123)51/( 210/ 191)46/( 172/ -1)
DO_MARKER( 10, LED40 );
DO_MARKER( 10, LED40|LED48 );
DO_MARKER( 10, LED40 );
DO_MARKER( 10, LED40|LED50 );
DO_MARKER( 10, LED40 );
POST 0: 16 (b35c) - 44 50 48 ab 01 b7 01 ab 01 b2 01 a9 01 38 c4 5c 86 12 bb 91
Events (-1285766088): 48/( 171/ 183)50/( 171/ 178)44/( 169/ -1)
It can totally move onto additional packets;
DO_MARKER( 10, LED40 );
DO_MARKER( 10, LED40|LED48 );
DO_MARKER( 10, LED40 );
DO_MARKER( 10, LED40|LED50 );
DO_MARKER( 10, LED40 );
DO_MARKER( 10, LED40|LED48 );
DO_MARKER( 10, LED40 );
DO_MARKER( 10, LED40|LED50 );
DO_MARKER( 10, LED40 );
POST 0: 21 (632c) - 50 48 50 48 b7 01 ab 01 b2 01 9f 01 c1 01 a0 01 bd 01 44 8a 2c f8 37 e7 3c
Events (1663863364): 48/( 183/ 171)50/( 178/ 159)48/( 193/ 160)50/( 189/ -1)
POST 2: 6 (632f) - 40 a4 0c ed 8a 2c 6b bc ea 55
Events (1663863533): 40/( 1572/ -1)
DO_MARKER( 14, LED40 );
DO_MARKER( 14, LED40|LED48 );
DO_MARKER( 14, LED40 );
DO_MARKER( 14, LED40|LED50 );
DO_MARKER( 14, LED40 );
DO_MARKER( 14, LED40|LED48 );
DO_MARKER( 14, LED40 );
DO_MARKER( 14, LED40|LED50 );
DO_MARKER( 14, LED40 );
DO_MARKER( 14, LED40|LED48 );
DO_MARKER( 14, LED40 );
POST 0: 6 (d7ce) - 40 8a 15 1a 0f ce 00 25 9a 03
Events (-674361574): 40/( 2698/ -1)
POST 0: 26 (d7d1) - 48 50 48 50 48 fc 01 f2 01 f8 01 ee 01 80 02 ef 01 f9 01 f3 01 fd 01 19 66 d2 d7 07 c8 40
Events (-674077159): 48/( 252/ 242)50/( 248/ 238)48/( 256/ 239)50/( 249/ 243)48/( 253/ -1)
POST 2: 6 (d7d4) - 40 89 15 04 67 d2 b3 ad 71 4e
Events (-674076924): 40/( 2697/ -1)
NOTICE: The second timecode is actually less than the first, and so we know the time code in the packet
corresponds to the start edge of the event, not the tailing edge of the event... I hope?
DO_MARKER( 14, LED40 );
DO_MARKER( 14, LED40|LED48 );
DO_MARKER( 14, LED40|LED48|LED50 );
DO_MARKER( 14, LED40|LED50 );
DO_MARKER( 14, LED40 );
POST 0: 16 (55b3) - 44 51 49 f1 01 f8 01 f9 01 f1 01 f2 01 fb 99 b5 96 78 95 4c
Events (1437964795): 49/( 241/ 248)51/( 249/ 241)44/( 242/ -1)
DO_MARKER( 14, LED40 );
DO_MARKER( 28, LED40|LED48 );
DO_MARKER( 14, LED40|LED48|LED50 );
DO_MARKER( 14, LED40|LED50 );
DO_MARKER( 14, LED40 );
POST 0: 16 (d8f1) - 44 51 49 f1 01 ef 03 f7 01 f4 01 f1 01 19 de f2 20 ee f9 82
Events (-655172071): 49/( 241/ 495)51/( 247/ 244)44/( 241/ -1)
POST 0: 16 (d8f7) - 44 51 49 f1 01 ee 03 f7 01 f5 01 f1 01 a3 32 f7 bd 50 64 dc
Events (-654888285): 49/( 241/ 494)51/( 247/ 245)44/( 241/ -1)
DO_MARKER( 14, LED40 );
DO_MARKER( 28, LED40|LED48 );
DO_MARKER( 14, LED40|LED48|LED50 );
DO_MARKER( 14, LED40|LED50 );
DO_MARKER( 14, LED40|LED48|LED50 );
DO_MARKER( 14, LED40 );
POST 0: 20 (48e6) - 46 49 52 49 f2 01 ec 03 f7 01 d1 01 97 02 82 ef 01 cf 77 e6 36 51 12 5b
Events (1223063503): 49/( 242/ 492)52/( 247/ 209)49/( 279/ 2)46/( 239/ -1)
DO_MARKER( 14, LED50 );
DO_MARKER( 28, LED50|LED48 );
DO_MARKER( 14, LED50|LED48|LED40 );
DO_MARKER( 14, LED50|LED40 );
DO_MARKER( 14, LED50|LED48|LED40 );
DO_MARKER( 14, LED50 );
POST 0: 20 (fab4) - 56 49 42 49 f4 01 f2 03 f4 01 d1 01 96 02 84 e9 01 f1 07 b5 62 27 b9 26
Events ( -88799247): 49/( 244/ 498)42/( 244/ 209)49/( 278/ 4)56/( 233/ -1)
Changing second to last LED
DO_MARKER( 14, LED50 );
DO_MARKER( 28, LED50|LED48 );
DO_MARKER( 14, LED50|LED48|LED40 );
DO_MARKER( 14, LED50|LED40 );
DO_MARKER( 14, LED50|LED48|LED40 );
DO_MARKER( 14, LED50|LED40 );
DO_MARKER( 14, LED50 );
POST 0: 21 (665d) - 56 43 48 49 f6 01 fb 03 e4 01 d6 01 95 02 ec 01 f2 01 67 ad 5f 24 9c 44 80
Events (1717546343): 49/( 246/ 507)48/( 228/ 214)43/( 277/ 236)56/( 242/ -1)
DO_MARKER( 14, LED50 );
DO_MARKER( 28, LED50|LED48 );
DO_MARKER( 14, LED50|LED48|LED40 );
DO_MARKER( 14, LED50|LED40 );
DO_MARKER( 14, LED50|LED48|LED40 );
DO_MARKER( 14, LED50|LED48 );
DO_MARKER( 14, LED50 );
POST 0: 21 (af86) - 56 49 42 49 f7 01 fb 03 e5 01 d6 01 8b 02 81 02 e8 01 05 0c 86 92 22 2e fd
Events (-1350169595): 49/( 247/ 507)42/( 229/ 214)49/( 267/ 257)56/( 232/ -1)
^^ Look, this changed.
DO_MARKER( 90, LED48 );
DO_MARKER( 14, LED48|LED40 );
DO_MARKER( 28, LED40 );
DO_MARKER( 56, LED48|LED40 );
DO_MARKER( 10, LED48 );
POST 0: 16 (ce15) - 49 42 49 bf 0c de 01 ec 03 d6 07 b2 01 35 f7 15 51 a0 c8 09
Events (-837421259): 49/( 1599/ 222)42/( 492/ 982)49/( 178/ -1)
POST 0: 16 (ce1b) - 49 42 49 bd 0c df 01 ed 03 d6 07 b2 01 ed 53 1a 99 a3 8c 0e
Events (-837135379): 49/( 1597/ 223)42/( 493/ 982)49/( 178/ -1)
DO_MARKER(40, LED40);
_delay_us(5);
DO_MARKER(80, LED50);
POST 0: 11 (6255) - 50 40 a4 05 9b 01 f4 0a d3 c9 56 82 f0 85 a3
Events (1649854931): 40/( 676/ 155)50/( 1396/ -1)
DO_MARKER(40, LED40);
DO_MARKER(80, LED48|LED40);
DO_MARKER(40, LED40);
POST 0: 12 (409a) - 48 40 e0 15 fb 22 11 f6 0a 47 9a 9a 0a 5e e3 4d
Events (1083873863): 40/( 2784/283003)48/( 1398/ -1)
DO_MARKER(40, LED40);
DO_MARKER(80, LED48|LED40);
DO_MARKER(40, LED40);
_delay_us(10);
DO_MARKER(40, LED40);
DO_MARKER(80, LED48|LED40);
DO_MARKER(40, LED40);
POST 0: 22 (f2cb) - 48 42 48 40 fe 15 f9 1b 11 b4 05 f6 0a b6 05 f2 07 ee 0a 01 8c ca 77 f1 74 e4
Events (-221606911): 40/( 2814/282105)48/( 692/ 1398)42/( 694/ 1010)48/( 1390/ -1)
2's bit mayhem:
DO_MARKER(40, LED40);
DO_MARKER(80, LED48|LED40);
DO_MARKER(40, LED40);
Events ( 669590803): 40/( 2785/283104)48/( 1400/ -1)
DO_MARKER(40, LED48);
DO_MARKER(80, LED48|LED40);
DO_MARKER(40, LED48);
Events (-2138863588): 48/( 2803/282920)40/( 1380/ -1)
DO_MARKER(40, LED48);
DO_MARKER(80, LED48|LED40);
DO_MARKER(40, LED40);
POST 0: 11 (cf74) - 41 49 ce 05 e8 0a bb 05 4c 95 76 1e 8d 62 68
Events (-814312116): 49/( 718/ 1384)41/( 699/ -1)
Continuing...
//WHY IS THE ORDER REVERSED?!?!??!??
DO_MARKER(10, LED48);
_delay_us(500);
DO_MARKER(250, LED40);
Events (-2113688082): 40/( 4359/282445)48/( 165/ -1)
DO_MARKER(10, LED40|LED50);
POST 0: 9 (9af3) - 52 40 98 85 01 94 a0 66 f4 16 8a e6 2a
Events (-1695258976): 40/( 24/ 133)52/( 20/ -1)
DO_MARKER(20, LED40);
_delay_us(10);
DO_MARKER(30, LED50);
_delay_us(10);
DO_MARKER(40, LED48);
_delay_us(10);
DO_MARKER(50, LED40);
POST 0: 21 (fc73) - 40 48 50 40 b5 02 ad 02 8d 04 a2 02 b3 05 bb 02 c5 06 56 85 74 22 a2 36 96
Events ( -59472554): 40/( 309/ 301)50/( 525/ 290)48/( 691/ 315)40/( 837/ -1)
DO_MARKER(20, LED40);
DO_MARKER(20, LED50|LED40);
DO_MARKER(20, LED50);
DO_MARKER(20, LED50|LED48);
DO_MARKER(20, LED50);
POST 0: 16 (b269) - 53 48 41 c8 02 cd 02 f7 02 d6 02 d6 02 77 a8 6a d8 2d 7c 19
Events (-1301632905): 41/( 328/ 333)48/( 375/ 342)53/( 342/ -1)
DO_MARKER(10, LED40);
DO_MARKER(20, LED50|LED40);
DO_MARKER(30, LED50);
DO_MARKER(40, LED50|LED48);
DO_MARKER(50, LED50);
Events ( -3705027): 41/( 151/ 334)48/( 552/ 695)53/( 867/ -1)
**********CHANGED OSCILLATOR SPEED SO NUMBERS ARE ABOUT 1/10TH OF CLKs.
The following is in reference to Alan Yates' picture on twitter.
https://twitter.com/vk2zay/status/805989864311132160
DO_MARKER(10, LED40);
DO_MARKER(20, LED50|LED40);
DO_MARKER(30, LED50);
DO_MARKER(40, LED50|LED48);
DO_MARKER(50, LED50);
POST 0: 15 (7d39) - 53 48 41 f8 a8 02 f9 03 ef 04 98 06 8b 68 3a 45 8b d9 26
Events (2100979851): 41/( 120/ 296)48/( 505/ 623)53/( 792/ -1)
DO_MARKER(10, LED40);
DO_MARKER(20, LED50|LED40);
DO_MARKER(50, LED50);
DO_MARKER(80, LED50|LED48);
DO_MARKER(110, LED50);
Events (-1091897926): 50/( 4118/254995)40/( 417/ 823)48/( 1258/ -1)
DO_MARKER(10, LED40);
DO_MARKER(20, LED50|LED40);
DO_MARKER(30, LED50);
DO_MARKER(50, LED50|LED48);
DO_MARKER(70, LED50);
POST 0: 15 (77b3) - 53 48 41 fa a8 02 fa 03 8f 06 d4 08 0f 74 b4 c9 fd d7 29
Events (2008314895): 41/( 122/ 296)48/( 506/ 783)53/( 1108/ -1)
DO_MARKER(10, LED40);
DO_MARKER(20, LED50|LED40);
DO_MARKER(30, LED50);
DO_MARKER(50, LED50|LED48);
DO_MARKER(80, LED50);
POST 0: 17 (d2d8) - 48 40 50 / a7 16 / f4 / 49 0f / a2 03 / fa 03 / 90 06 / 58 a6 d9 / bf 3f bf d8
Events (-757488040): 50/( 2855/255220)40/( 418/ 506)48/( 784/ -1) << Yeah, I'm decoding the 255220 right, I think?
FOUND SOMETHING NEW!!!: 255220−(262144) = −6924 !!! << Ok, nevermind.
They say not to look here, but, I don't get it. Otherwise, it's a mess of 1's and zeros.
"Ben Jackson you're sending a sequence ab ab ab ab and seeing "b a" b a" "b a" come out "
"Ben Jackson it's not a bug"
"Albert Fletcher Edwin called it"
When switching the _delay_ms(...) to 11 from 10...
POST 0: 17 (b3ac) - 48 40 50 ab 16 8e 14 11 a1 03 fb 03 8f 06 b5 2b ad 0b be 45 82
Events (-1280496715): 50/( 2859/281102)40/( 417/ 507)48/( 783/ -1)
that big number is different now.
...then with... _delay_ms(32);
Events (-992766494): 50/( 2849/816305)40/( 420/ 505)48/( 782/ -1)
Ben Jackson well now your debug data is so different from real data that you're seeing strangeness
Ben Jackson but the thing you're decoding is still accurate
vk2zay the delta decoding around line 357 isn't correct
Ben Jackson oh, not all his coding
Ben Jackson but my coding is accurately representing reality
Ben Jackson @cai it wouldn't, but in a real system there's a lot more data flying around
Cai Biesinger Ah, OK. That makes sense. What's the maximum time a controller would theoretically hold data?
Ben Jackson @cai not sure
switching to: _delay_ms(32);
Now, flirting with limit.
DO_MARKER(20, LED40);
DO_MARKER(35, LED50|LED40);
DO_MARKER(25, LED50);
DO_MARKER(45, LED50|LED48);
DO_MARKER(65, LED50);
Events (1574058667): 41/( 283/ 536)48/( 427/ 704)53/( 1031/ -1)
POST 0: 16 (5ddc) - 53 48 41 9b 02 99 04 ab 03 bf 05 88 08 98 c2 de 86 68 4c ac
Events (1574879896): 41/( 283/ 537)48/( 427/ 703)53/( 1032/ -1)
POST 0: 11 (5deb) - 48 40 b3 06 ac 03 c0 05 cc 45 eb eb 91 c5 bd
Events (1575699916): 40/( 819/ 428)48/( 704/ -1)
POST 0: 22 (5df6) - 53 48 41 50 8d 15 9e 77 31 9b 02 98 04 ab 03 bf 05 88 08 17 d1 f7 99 e3 75 80
Events (1576522007): 50/( 2701/818078)41/( 283/ 536)48/( 427/ 703)53/( 1032/ -1)
POST 0: 16 (5e02) - 53 48 41 99 02 98 04 ab 03 bf 05 86 08 f6 55 04 df 6e 8b 3e
Events (1577342454): 41/( 281/ 536)48/( 427/ 703)53/( 1030/ -1)
POST 0: 16 (5e0e) - 53 48 41 9b 02 98 04 ac 03 bf 05 88 08 ae dc 10 1e 35 03 35
Now this is flirting with the limit and wrapping around.
TODO TODO TODO : Look at these values and try to figure out what's wrong with the deltaA / deltaB code in survive_data.c
COMMIT. Libsurvive hash 09efa97
APPENDIX: Before I started doing inline "ben"ments I kept a log here is that log:
Ben Jackson says: not sure what's going wrong with haptics. I think there's only one command, and it's pulse duration in microseconds, and shouldn't exceed about 3500
Ben Jackson the 3 byte direct time is the first edge of the first hit
Ben Jackson
Ben Jackson there are only 2n-1 deltas
Ben Jackson: it's "first one to end first"
Ben Jackson when a pulse goes high, you don't know when it will end
Ben Jackson
Ben Jackson you can't report it until it ends
Ben Jackson
Ben Jackson so they come out in the order they end
Ben Jackson no, I can't explain the LSBs in terms of his current code
Daniel Wee that explains why the higher bits didn't show up until we had more LEDs in play
Ben Jackson he's got to fix his time decode first
Ben Jackson the starts and ends are all mixed. they have to be, with all positive deltas, right?
Ben Jackson it's literally start,d0,d1,d2,d3 making times start+d0, start+d0+d1, start+d0+d1+d2, ...
Ben Jackson those are all edges
Ben Jackson then you need the LSBs to figure out which edges go where
Ben Jackson consider nested pulses that look like rise rise fall fall, vs sequential rise fall rise fall
Ben Jackson then the decoded times go with different things
vk2zay what is 2^18
Ben Jackson Stupid question or Socratic method?
Ben Jackson I think this might be a more productive stream if it tried to *compress* the data
Ben Jackson in the process you'd probably come to a bunch of the same conclusions I did
Ben Jackson vee kay two zay is what I'm calling him from now on
The whole thing about 2^18, and it mapping into the 2's bit of the timecode + 65536, instead of
the 2's bit of the LED code.
vk2zay getting there
Daniel Wee your sequence of numbers only applies to the first few bytes - but the assignment to the timestamps may be wrong
Ben Jackson vk2zay explaining in pictures while I snag leftover Indian food
(Picture from Twitter)
Ben Jackson oh, are you in SEA Luke?
Ben Jackson I guess Phil did say something like that
training
Ben Jackson MAKING ALL YOUR TIMINGS IDENTICAL IS MAKING YOUR LIFE SO MUCH HARDER
Ben Jackson too bad all caps doesn't actually yell
Ben Jackson we need to be able to pay $1 to have a bad speech synthesizer repeat on stream
Ben Jackson vk2zay about to discover I got the last samosa
Ben Jackson @scanlime with the classic "all example numbers should be prime so no one can mistake them for anything"
Ben Jackson there is nothing of interest in the nRF24
Ben Jackson that's your whole problem, really
Ben Jackson I didn't decode it in the nRF24
Charles: "Can I record this and put it in the gist?: Ben Jackson sure, I wouldn't say anything in chat without expecting it to be public
Is it encoded in the FPGA? Ben Jackson @Na it's encoded in the controller side in an nRF51
Ben Jackson no, @scanlime guessed it was done in the FPGA
Ben Jackson the fpga outputs yet another different format over SPI
Ben Jackson but I bet you could reverse engineer that in 10 minutes
Ben Jackson well, we're not going to try to lock you out
Ben Jackson but we're going to add features someday that break this without caring that it will break you
vk2zay we would only change the protocol to add features
Ben Jackson I think eventually we'll let you do your own wireless protocol
Ben Jackson but it's not a huge priority and there's only so much time
On the gist, when I realize the big number is about - 6k.
Ben Jackson how big is your delay between batches?
Ben Jackson it's not negative
Ben Jackson whatever it is
Ben Jackson noooo
vk2zay it is not a -ve number
Ben Jackson need that chat vocoder
When I started switching the time coding...
Ben Jackson you're just wrapping around and seeing two of your events in one packet
Ben Jackson also your delay probably isn't 11ms. it's probably 280000/48e6 seconds
Ben Jackson it's not "freaking out", it's just combining them
vk2zay well I got it
APPENDIX B: Nairol from lighthouse-redux chimes in on Reddit in: https://www.reddit.com/r/Vive/comments/5gmk7l/i_live_streamed_hacking_the_vive_got_a_vive/
>>> Thanks for the kind words about Lighthouse Redox. (I did most of the initial reverse-engineering work by disassembling the base station firmware) It was meant as a resource for people interested in Lighthouse to build their own hard- and software and share their findings about the system before the eventual official documentation release by Valve (which never happened publically). I'm happy that finally people actually use it. It has been up since a few days before the release of the Vive. :)
>>> I know the repo is in a pretty bad state and lots of pieces are still missing. It hasn't been updated in months... This is partially because of laziness, partially because of my job but for the most part because I lost almost all my data (not just the Lighthouse-related stuff) to a HDD defect. The data recovery lab told me it has a misaligned read/write head with some impact damage to the disk surface. I might get most of the data back but it takes months. Of course I didn't have a backup.
>>> The wireless receiver data really is a mess. I remember sitting in front of a scrolling console window and trying to figure out WTF was going on. Until I accidentally covered the photodiodes and the data started to make sense. :)
>>> I have only watched the first 30 minutes of the screencast so I don't know how much you already know out about the protocol. I've given up on trying to reconstruct how the light pulse data is multiplexed into the data stream just by looking at the USB data. It seems to be encoded into the time stamp and an additional byte but it just doesn't make sense to me. Also there seems to be some kind of checksum (CRC32?) but I couldn't figure out what byte range it coveres...
>>> I wanted to have a look at the firmware for the controller and the wireless receiver to finally solve this riddle but haven't found the time or motivation yet. Disassembling the firmware is fast but finding the stuff you're interested in takes hours and hours of scrolling through walls of mostly boring assembly code.
>>> If you have questions I might be able to help out a bit. But don't count on it since I haven't been following the VR subreddits and haven't done any work on the Vive internals for quite some time.
>>> edit:
>>> @0:43:15
>>> I don't know who told you 2MHz was the correct modulation frequency but it should be 1.843200 MHz. (Link Ctrl+F "carrier.frequency") But 2MHz is good enough.
>>> @0:48:12
>>> I reverse-engineered the stuff on the USB protocol page the same way as you did. So that shouldn't be a problem. Most of the other documentation comes from the base station firmware but I didn't include any code from there so your version can be considered "clean room implementation" AFAIK. I've also told Alan Yates from Valve that I was disassembling his firmware and he didn't seem to have a problem with that.
>>> @x:xx:xx
>>> Afaik all microcontrollers in the system are ARM Cortex M0+ architecture with the Thumb2 instruction set. Haven't seen any 8051 code in the firmware files.
@cnlohr
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cnlohr commented Dec 9, 2016

Ok, this is weird, a little bit later (and updated algorithm), it gives me this:

POST 0:   10 (8b05) - 51 41 bc 02 b5 02 89 6d b6 05 65 42 73 7e 
8: 625 [373747]
10: 318 [374063]
POST 0:   25 (8b11) - 50 40 41 51 48 d3 1d e0 76 31 82 bb 02 b6 02 d9 03 c1 02 8a bc 02 6a 3a 12 53 88 0f b0 
9: 3795 [371044]
10: 317 [1192855]
8: 625 [1192857]
8: 321 [1193955]
10: 316 [1194286]
POST 0:   10 (8b11) - 51 41 bc 02 b4 02 89 c2 3e 12 54 3b 5f 45 
8: 624 [1195081]
10: 317 [1195397]
POST 0:   25 (8b1d) - 50 40 41 51 48 d1 1d ff 6e 31 81 bc 02 b6 02 d8 03 c1 02 8a bc 02 de be 1e 06 88 0f b0 
9: 3793 [1192380]
10: 317 [2013196]
8: 626 [2013197]
8: 321 [2014295]
10: 316 [2014626]

@Zmathue
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Zmathue commented Dec 9, 2016

yeah it was very odd seeing a negative number show up as the delta is actually larger than the time stamp. The width all pulses are exactly as expected (even id:9 which is way off at an earlier time).

and its only the one (id:9) that is so far delayed. I don't know if this is because it is in queue somewhere that is just backed up or if something else is going on.

1

the ones on the left are all id:9

2
this is a closer look at the ones on the right which look very good.

@cnlohr the new algorithm looks good, exactly what I got

@cnlohr
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cnlohr commented Dec 9, 2016

Ben says: "Kind of. We coalesce syncs because there are a lot of them (they hit all the sensors) so it conserves bandwidth. The syncs themselves aren't directly used to track, so we can wait for the actual hits to come to flush them out."

@Zmathue
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Zmathue commented Dec 9, 2016

okay that makes perfect sense, that's why the large offsets are only when you leave an led on for a long time, it passes the threshold where a pulse is no longer considered a hit and is now considered part of the sync flash.

@cnlohr
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cnlohr commented Dec 9, 2016

That is a little annoying from my side, as I average the sync flashes among all of the hit pulses on the headset, but I guess the headset matters more than the controllers.

@danweecc
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danweecc commented Dec 9, 2016

@Zmathue - the 51 or 50 is really easy to understand if you think in terms of an analog system with a lot of jitter. The rising edges of LED50 and LED48 happen at virtually the same moment but they are detected with some jitter. This means that in practice, LED50 could rise just a hair faster or slower than LED48, and depending on which one - there might be an extra edge-transition in the faster LED and one less in the slower LED.

@cnlohr
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cnlohr commented Dec 9, 2016

I have noticed sometimes delta is actually 0. But, when it is, everything /still/ works since you still individually use the edges.

@danweecc
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@cnlohr - maybe the 0-delta corresponds to a simultaneous edge.

@cnlohr
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cnlohr commented Dec 10, 2016

that's my feelings exactly. They happen when I purposefully make edges as simultaneous as I can.

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