DVDO VP20 用户手册

Let us break it up to decipher it.

Preamble

0000 0067 000 0015

Word 1

0 so it is a learned IR code

Word 2

103 decimal which when plugged into the formula

already given yields an IR Carrier frequency of about 40kHz.

Word 3

0000 is the length of the One Time Burst. There is

no one time burst

Word 4

Decimal 21 is the length of the repeat burst. There

are 21 bits (Burst pairs) in this code. The code length is 20
bits plus 1 more pair for the Lead in.

Word 5,6

0060 0018 (96,24 decimal) The lead in Burst . 4

units of on followed by 1 unit of off, where a unit is 600
microseconds

Word 7,8

0018 0018 (24,24 decimal) Burst pair 1, bit 1 = "0"

Word 9,10

0030 0018 (48,24 decimal) Burst Pair 2, bit 2 = "1"

Word 11,12

0030 0018 (48,24 decimal) Burst Pair 3, bit 3 = "1"

Word 13,14

0030 0018 (48,24 decimal) Burst Pair 4, bit 4 = "1"

Word 15,16

0018 0018 (24,24 decimal) Burst Pair 5, bit 5 = "0"

Word 17,18

0030 0018 (48,24 decimal) Burst Pair 6, bit 6 = "1"

Word 19,20

0018 0018 (24,24 decimal) Burst Pair 7, bit 7 = "0"

The above is the function code as transmitted it is 0111010. Reversing the string

so it is a true binary number with the least significant digit on the right we get 0101110
which in decimal is 46.