JP1 Remotes

jon_armstrong wrote:I put together a device and protocol upgrade using Protocol Builder (PB). Since you did a lot of research here is what I did:

In this case the fixed data according to the method of converting 00,01,10,and 11 ==> 0,01,011, and 0111 is:

00011101010100000110
That is 20 bits

The maximum value for OBC (255) is
0111011101110111 (16 bits)


But we must end with a 0 to get the on pulse of the lead out and we have to do it that way since the number of bits varies. (You must then pad after the 0 with sufficient 1's to get 16 bits). Fortunately, all OBC's will begin with a zero so we can add the zero to the last bit of fixed data. That way we can still do what we need in 16 variable bits or two bytes. since all the 1's after the final on pulse are just off times, we use a feature of PB that allows us to set a constant frame length in this case 100,516 uS.

We could have three 7-bit fixed bytes (if you have >2 bytes of fixed or >2 bytes of variable data then the fixed or varaible bytes must all be the same byte width), but I originally miscounted and and decided to use 24 bits of fixed data and put in 3 leading 111 (all off time so they are ignored) and used a mid frame burst after bit three as the lead-in.

My testing shows it to be decoding correctly so I think it will work. To convert the other OBC's that you decode use Excel and convert OBC to 8-bit binary, then convert each 2 bits as mentioned above. Then drop the most significant bit add a 0 as the least significant bit and then enough ones to make 16 bits and convert to two hex bytes.

For fixed data:

00011101010100000110
111 00011101010100000110 0 add three leading 1's and one trailing 0
11100011 10101010 00001100 rearranging
0xE3 0xAA 0x0C

For variable data:
OBC=1
00000001
00 00 00 01 ==> 0 0 0 01
00001 without the spaces
x00010 Drop the first msb 0 add lsb 0
00010 11111111111 add eleven 1's
00010111 11111111
0x17 0xFF