Help with understanding AC IR code

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Hi All,

I am trying to decode my AC ir codes, so far i have pretty good understanding of what every command is in the code, at list the ones who’s interesting to me: mode, fan, temp and on/off.

The problem is is that i could not figure the checksum function.
Below is some examples of code i got. The last 4 digits seems to me like a checksum, the first 4 digits are the mode and one bit for power on or off, the second 4 bits are for fan speed the 3rd 4 bits are for temp which in the example below is the only thing that is changed:
cold auto fan, temp:
16
1001 0000 0000 000000000110000010100100000000000000100000000000000 1010
17
1001 0000 1000 000000000110000010100100000000000000100000000000000 0110
18
1001 0000 0100 000000000110000010100100000000000000100000000000000 1110
19
1001 0000 1100 000000000110000010100100000000000000100000000000000 0001
20
1001 0000 0010 000000000110000010100100000000000000100000000000000 1001
21
1001 0000 1010 000000000110000010100100000000000000100000000000000 0101
22
1001 0000 0110 000000000110000010100100000000000000100000000000000 1101
23
1001 0000 1110 000000000110000010100100000000000000100000000000000 0011
24
1001 0000 0001 000000000110000010100100000000000000100000000000000 1011
25
1001 0000 1001 000000000110000010100100000000000000100000000000000 0111
26
1001 0000 0101 000000000110000010100100000000000000100000000000000 1111
27
1001 0000 1101 000000000110000010100100000000000000100000000000000 0000
28
1001 0000 0011 000000000110000010100100000000000000100000000000000 1000
29
1001 0000 1011 000000000110000010100100000000000000100000000000000 0100
30
1001 0000 0111 000000000110000010100100000000000000100000000000000 1100

Can some one please help? my eyes are red from looking at this for few days now

Thanks.

I got some more information, look at the checksum its the same for all commands:
cold, 26
Fan:

Auto
1001 0000 0101 0000 0000 0110 000 0101 0010 0000 0000 0000 0100 0000 0000 0000 1111

Fan1
1001 1000 0101 000000000110000010100100000000000000100000000000000 1111

Fan2
1001 0100 0101 000000000110000010100100000000000000100000000000000 1111

Fan3
1001 1100 0101 000000000110000010100100000000000000100000000000000 1111

Can any one see what i am missing?

So i got it to work, and made a library to activate the AC with arduino (i use it with MySensors).

Its a gree AC if anyone is interested.

Thanks.