kopia lustrzana https://github.com/xaelsouth/rtl-wmbus
run length algo for s1
Xael South
rodzic
7459c7e30a
commit
f53fd26781
2
atan2.h
2
atan2.h
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@ -6,7 +6,7 @@
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static inline float atan2_libm(float complex y)
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{
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return carg(y) * (float)M_1_PI;
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return cargf(y) * (float)M_1_PI;
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}
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121
rtl_wmbus.c
121
rtl_wmbus.c
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@ -50,12 +50,12 @@ static const uint32_t ACCESS_CODE_S1_BITMASK = 0x3FFFFu;
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static const unsigned ACCESS_CODE_S1_ERRORS = 1u; // 0 if no errors allowed
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/* deglitch_filter has been calculated by a Python script as follows.
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/* deglitch_filter_t1_c1 has been calculated by a Python script as follows.
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The filter is counting "1" among 7 bits and saying "1" if count("1") >= 3 else "0".
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Notice here count("1") >= 3. (More intuitive in that case would be count("1") >= 3.5.)
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That forces the filter to put more "1" than "0" on the output, because RTL-SDR streams
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more "0" than "1" - i don't know why RTL-SDR do this.
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x = 'static const uint8_t deglitch_filter[128] = {'
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x = 'static const uint8_t deglitch_filter_t1_c1[128] = {'
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mod8 = 8
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for i in range(2**7):
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@ -70,7 +70,7 @@ x += '};\n'
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print(x)
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*/
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static const uint8_t deglitch_filter[128] =
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static const uint8_t deglitch_filter_t1_c1[128] =
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{
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0,0,0,0,0,0,0,1,
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0,0,0,1,0,1,1,1,
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@ -90,6 +90,15 @@ static const uint8_t deglitch_filter[128] =
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1,1,1,1,1,1,1,1
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};
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static const uint8_t deglitch_filter_s1[16] = {
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// 0000 0001 0010 0011 0100 0101 0110 0111
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0, 1, 0, 1, 1, 1, 1, 1,
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// 1000 1001 1010 1011 1100 1101 1110 1111
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0, 1, 1, 1, 1, 1, 1, 1
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};
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static inline float moving_average_t1_c1(float sample, size_t i_or_q)
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{
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#define COEFFS 8
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@ -108,7 +117,7 @@ static inline float moving_average_t1_c1(float sample, size_t i_or_q)
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static inline float moving_average_s1(float sample, size_t i_or_q)
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{
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#define COEFFS 8
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#define COEFFS 16
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static int i_hist[COEFFS];
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static int q_hist[COEFFS];
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@ -408,7 +417,86 @@ static inline unsigned count_set_bits(uint32_t n)
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}
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struct runlength_algorithm
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struct runlength_algorithm_s1
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{
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int run_length;
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unsigned state;
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uint32_t raw_bitstream;
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uint32_t bitstream;
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int samples_per_bit[2];
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struct s1_packet_decoder_work decoder;
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};
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static void runlength_algorithm_reset_s1(struct runlength_algorithm_s1 *algo)
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{
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algo->run_length = 0;
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algo->state = 0u;
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algo->raw_bitstream = 0;
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algo->bitstream = 0;
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algo->samples_per_bit[0] = 24; // Data rate is 32768 bps which gives us approx. 24 samples
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algo->samples_per_bit[1] = 24; // at a sample rate of 800kHz (800kHz / 32768bps = 24.41 ~= 24 samples).
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reset_s1_packet_decoder(&algo->decoder);
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}
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static void runlength_algorithm_s1(unsigned raw_bit, unsigned rssi, struct runlength_algorithm_s1 *algo)
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{
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algo->raw_bitstream = (algo->raw_bitstream << 1) | raw_bit;
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const unsigned state = deglitch_filter_s1[algo->raw_bitstream & 0xFu];
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if (algo->state == state)
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{
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algo->run_length++;
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}
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else
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{
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const int samples_per_bit = (algo->samples_per_bit[0] + algo->samples_per_bit[1]) / 2;
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if (samples_per_bit <= 24/2)
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{
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runlength_algorithm_reset_s1(algo);
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algo->state = state;
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algo->run_length = 1;
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return;
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}
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const int run_length = algo->run_length;
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if (run_length <= samples_per_bit/2)
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{
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runlength_algorithm_reset_s1(algo);
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algo->state = state;
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algo->run_length = 1;
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return;
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}
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int num_of_bits_rx;
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for (num_of_bits_rx = 0; algo->run_length > samples_per_bit/2; num_of_bits_rx++)
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{
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algo->run_length -= samples_per_bit;
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unsigned bit = algo->state;
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algo->bitstream = (algo->bitstream << 1) | bit;
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if (count_set_bits((algo->bitstream & ACCESS_CODE_S1_BITMASK) ^ ACCESS_CODE_S1) <= ACCESS_CODE_S1_ERRORS)
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{
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bit |= (1u<<PACKET_PREAMBLE_DETECTED_SHIFT); // packet detected; mark the bit similar to "Access Code"-Block in GNU Radio
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}
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s1_packet_decoder(bit, rssi, &algo->decoder, "rla;");
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}
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//fprintf(stdout, "%u, %d, bits: %d, 0: %u, 1: %u\n", algo->state, run_length, num_of_bits_rx, algo->samples_per_bit[0], algo->samples_per_bit[1]);
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algo->samples_per_bit[algo->state] = run_length / num_of_bits_rx;
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algo->state = state;
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algo->run_length = 1;
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}
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}
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struct runlength_algorithm_t1_c1
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{
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int run_length;
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int bit_length;
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@ -420,7 +508,7 @@ struct runlength_algorithm
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};
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static void runlength_algorithm_reset(struct runlength_algorithm *algo)
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static void runlength_algorithm_reset_t1_c1(struct runlength_algorithm_t1_c1 *algo)
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{
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algo->run_length = 0;
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algo->bit_length = 8 * 256;
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@ -432,11 +520,11 @@ static void runlength_algorithm_reset(struct runlength_algorithm *algo)
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}
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static void runlength_algorithm(unsigned raw_bit, unsigned rssi, struct runlength_algorithm *algo)
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static void runlength_algorithm_t1_c1(unsigned raw_bit, unsigned rssi, struct runlength_algorithm_t1_c1 *algo)
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{
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algo->raw_bitstream = (algo->raw_bitstream << 1) | raw_bit;
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const unsigned state = deglitch_filter[algo->raw_bitstream & 0x3Fu];
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const unsigned state = deglitch_filter_t1_c1[algo->raw_bitstream & 0x3Fu];
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if (algo->state == state)
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{
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@ -446,7 +534,7 @@ static void runlength_algorithm(unsigned raw_bit, unsigned rssi, struct runlengt
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{
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if (algo->run_length < 5)
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{
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runlength_algorithm_reset(algo);
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runlength_algorithm_reset_t1_c1(algo);
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algo->state = state;
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algo->run_length = 1;
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return;
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@ -460,7 +548,7 @@ static void runlength_algorithm(unsigned raw_bit, unsigned rssi, struct runlengt
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if (algo->run_length <= half_bit_length)
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{
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runlength_algorithm_reset(algo);
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runlength_algorithm_reset_t1_c1(algo);
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algo->state = state;
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algo->run_length = 1;
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return;
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@ -717,8 +805,11 @@ int main(int argc, char *argv[])
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struct time2_algorithm_s1 t2_algo_s1;
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time2_algorithm_s1_reset(&t2_algo_s1);
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struct runlength_algorithm rl_algo;
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runlength_algorithm_reset(&rl_algo);
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struct runlength_algorithm_t1_c1 rl_algo_t1_c1;
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runlength_algorithm_reset_t1_c1(&rl_algo_t1_c1);
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struct runlength_algorithm_s1 rl_algo_s1;
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runlength_algorithm_reset_s1(&rl_algo_s1);
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FILE *input = stdin;
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//input = fopen("samples/samples2.bin", "rb");
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@ -841,13 +932,16 @@ int main(int argc, char *argv[])
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#if 1
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if (opts_run_length_algorithm_enabled)
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{
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runlength_algorithm(bit_t1_c1, rssi_t1_c1, &rl_algo);
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runlength_algorithm_t1_c1(bit_t1_c1, rssi_t1_c1, &rl_algo_t1_c1);
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runlength_algorithm_s1(bit_s1, rssi_s1, &rl_algo_s1);
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}
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// --- runlength algorithm section end ---
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#endif
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// --- time2 algorithm section begin ---
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#if 1
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if (opts_time2_algorithm_enabled)
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{
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// --- clock recovery section begin ---
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@ -902,6 +996,7 @@ int main(int argc, char *argv[])
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old_clock_s1 = clock_s1;
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// --- clock recovery section end ---
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}
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#endif
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// --- time2 algorithm section end ---
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}
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}
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