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Started writing (copying...) AFSK RX

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Encoders: removed bit duration setting (frame duration is more useful)
This commit is contained in:
furrtek
2017-08-29 09:42:04 +01:00
parent cd6a1a7f3f
commit 42439d1885
23 changed files with 453 additions and 423 deletions
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firmware/application/de_bruijn.cpp
+24 -3
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@@ -26,10 +26,10 @@
* B(2,4) means:
* Alphabet size = 2 (binary)
* Code length = 4
* The length of the bitstream is (2 ^ 4) - 1 = 15
* The length of the bitstream is (2 ^ 4) + (4 - 1) = 19 bits
* The primitive polynomials come from the de_bruijn_polys[] array (one for each code length)
* The shift register is init with 1 and shifted left each step
* The polynomial is kept on the right, and ANDed with the corresponding shift register bits
* The polynomial is kept on the right, and used as a AND mask applied on the corresponding shift register bits
* The resulting bits are XORed together to produce the new bit pushed in the shift register
*
* 0001 (init)
@@ -52,9 +52,28 @@
* AND 1001
* 1000 XOR'd -> 1
* ...
* After 16 steps: (0+) 000111101011001000
* Each of the 16 possible values appears in the sequence:
* -0000-111101011001000 0
* 0-0001-11101011001000 1
* 0000111101011-0010-00 2
* 00-0011-1101011001000 3
* 00001111010110-0100-0 4
* 00001111-0101-1001000 5
* 0000111101-0110-01000 6
* 000-0111-101011001000 7
* 000011110101100-1000- 8
* 000011110101-1001-000 9
* 0000111-1010-11001000 10
* 000011110-1011-001000 11
* 00001111010-1100-1000 12
* 000011-1101-011001000 13
* 00001-1110-1011001000 14
* 0000-1111-01011001000 15
*/
void de_bruijn::init(const uint32_t n) {
size_t de_bruijn::init(const uint32_t n) {
// Cap
if ((n < 3) || (n > 16))
length = 3;
else
@@ -62,6 +81,8 @@ void de_bruijn::init(const uint32_t n) {
poly = de_bruijn_polys[length - 3];
shift_register = 1;
return (1U << length) + (length - 1);
}
uint32_t de_bruijn::compute(const uint32_t steps) {