/*
* Decodes the following encoding scheme:
* 10 = 0
* 1100 = 1
*/
unsigned ge_decode(r_device *decoder, bitbuffer_t *inbuf, unsigned row, unsigned start, bitbuffer_t *outbuf)
{
uint8_t *bits = inbuf->bb[row];
unsigned int len = inbuf->bits_per_row[row];
unsigned int ipos = start;
while (ipos < len) {
uint8_t bit1, bit2;
bit1 = bit(bits, ipos++);
bit2 = bit(bits, ipos++);
if (bit1 == 1 && bit2 == 0) {
bitbuffer_add_bit(outbuf, 0);
} else if (bit1 == 1 && bit2 == 1) {
// Get two more bits
bit1 = bit(bits, ipos++);
bit2 = bit(bits, ipos++);
if (bit1 == 0 && bit2 == 0) {
bitbuffer_add_bit(outbuf, 1);
} else {
break;
}
} else {
break;
}
}
return ipos;
}
int main(int argc, char **argv) {
fprintf(stderr, "bitbuffer:: test\n");
bitbuffer_t bits = {0};
fprintf(stderr, "TEST: bitbuffer:: The empty buffer\n");
bitbuffer_print(&bits);
fprintf(stderr, "TEST: bitbuffer:: Add 1 bit\n");
bitbuffer_add_bit(&bits, 1);
bitbuffer_print(&bits);
fprintf(stderr, "TEST: bitbuffer:: Add 1 new row\n");
bitbuffer_add_row(&bits);
bitbuffer_print(&bits);
fprintf(stderr, "TEST: bitbuffer:: Fill row\n");
for (int i=0; i < BITBUF_COLS*8; ++i) {
bitbuffer_add_bit(&bits, i%2);
}
bitbuffer_print(&bits);
fprintf(stderr, "TEST: bitbuffer:: Add row and fill 1 column too many\n");
bitbuffer_add_row(&bits);
for (int i=0; i <= BITBUF_COLS*8; ++i) {
bitbuffer_add_bit(&bits, i%2);
}
bitbuffer_print(&bits);
fprintf(stderr, "TEST: bitbuffer:: Clear\n");
bitbuffer_clear(&bits);
bitbuffer_print(&bits);
fprintf(stderr, "TEST: bitbuffer:: Add 1 row too many\n");
for (int i=0; i <= BITBUF_ROWS; ++i) {
bitbuffer_add_row(&bits);
}
bitbuffer_add_bit(&bits, 1);
bitbuffer_print(&bits);
return 0;
}
static int lightwave_rf_callback(bitbuffer_t *bitbuffer) {
bitrow_t *bb = bitbuffer->bb;
// Validate package
// Transmitted pulses are always 72
// Pulse 72 (delimiting "1" is not demodulated, as gap becomes End-Of-Message - thus expected length is 71
if ((bitbuffer->bits_per_row[0] == 71)
&& (bitbuffer->num_rows == 1)) // There should be only one message (and we use the rest...)
{
// Polarity is inverted
bitbuffer_invert(bitbuffer);
// Expand all "0" to "10" (bit stuffing)
// row_in = 0, row_out = 1
bitbuffer_add_row(bitbuffer);
for (unsigned n=0; n < bitbuffer->bits_per_row[0]; ++n) {
if (bitrow_get_bit(bb[0], n)) {
bitbuffer_add_bit(bitbuffer, 1);
} else {
bitbuffer_add_bit(bitbuffer, 1);
bitbuffer_add_bit(bitbuffer, 0);
}
}
// Check length is correct
// Due to encoding there will be two "0"s per byte, thus message grows to 91 bits
if (bitbuffer->bits_per_row[1] != 91) return 0;
// Check initial delimiter bit is "1"
unsigned bit_idx = 0;
uint8_t delimiter_bit = bitrow_get_bit(bb[1], bit_idx++);
if (delimiter_bit == 0) return 0; // Decode error
// Strip delimiter bits
// row_in = 1, row_out = 2
bitbuffer_add_row(bitbuffer);
for(unsigned n=0; n<10; ++n) { // We have 10 bytes
delimiter_bit = bitrow_get_bit(bb[1], bit_idx++);
if (delimiter_bit == 0) return 0; // Decode error
for(unsigned m=0; m<8; ++m) {
bitbuffer_add_bit(bitbuffer, bitrow_get_bit(bb[1], bit_idx++));
}
}
// Final delimiter bit will be missing - so do not check...
// Decode bytes to nibbles
// row_in = 2, row_out = 3
bitbuffer_add_row(bitbuffer);
for(unsigned n=0; n<10; ++n) { // We have 10 bytes/nibbles
int nibble = lightwave_rf_nibble_from_byte(bb[2][n]);
if (nibble < 0) {
if (debug_output) {
fprintf(stderr, "LightwaveRF. Nibble decode error %X, idx: %u\n", bb[2][n], n);
bitbuffer_print(bitbuffer);
}
return 0; // Decode error
}
for (unsigned m=0; m<4; ++m) { // Add nibble one bit at a time...
bitbuffer_add_bit(bitbuffer, (nibble & (8 >> m)) >> (3-m));
}
}
// Print out generic decode
// Decoded nibbles are in row 3
fprintf(stdout, "LightwaveRF:\n");
fprintf(stdout, "ID = 0x%X%X%X\n", bb[3][2], bb[3][3], bb[3][4]);
fprintf(stdout, "Subunit = %u\n", (bb[3][1] & 0xF0) >> 4);
fprintf(stdout, "Command = %u\n", bb[3][1] & 0x0F);
fprintf(stdout, "Parameter = %u\n", bb[3][0]);
if (debug_output) {
bitbuffer_print(bitbuffer);
fprintf(stderr, " Row 0 = Input, Row 1 = Zero bit stuffing, Row 2 = Stripped delimiters, Row 3 = Decoded nibbles\n");
}
return 1;
}
static void classify_signal() {
unsigned int i, k, max = 0, min = 1000000, t;
unsigned int delta, count_min, count_max, min_new, max_new, p_limit;
unsigned int a[3], b[2], a_cnt[3], a_new[3], b_new[2];
unsigned int signal_distance_data[4000] = {0};
struct protocol_state p = {0};
unsigned int signal_type;
if (!signal_pulse_data[0][0])
return;
for (i = 0; i < 1000; i++) {
if (signal_pulse_data[i][0] > 0) {
//fprintf(stderr, "[%03d] s: %d\t e:\t %d\t l:%d\n",
//i, signal_pulse_data[i][0], signal_pulse_data[i][1],
//signal_pulse_data[i][2]);
if (signal_pulse_data[i][2] > max)
max = signal_pulse_data[i][2];
if (signal_pulse_data[i][2] <= min)
min = signal_pulse_data[i][2];
}
}
t = (max + min) / 2;
//fprintf(stderr, "\n\nMax: %d, Min: %d t:%d\n", max, min, t);
delta = (max - min)*(max - min);
//TODO use Lloyd-Max quantizer instead
k = 1;
while ((k < 10) && (delta > 0)) {
min_new = 0;
count_min = 0;
max_new = 0;
count_max = 0;
for (i = 0; i < 1000; i++) {
if (signal_pulse_data[i][0] > 0) {
if (signal_pulse_data[i][2] < t) {
min_new = min_new + signal_pulse_data[i][2];
count_min++;
} else {
max_new = max_new + signal_pulse_data[i][2];
count_max++;
}
}
}
if (count_min != 0 && count_max != 0) {
min_new = min_new / count_min;
max_new = max_new / count_max;
}
delta = (min - min_new)*(min - min_new) + (max - max_new)*(max - max_new);
min = min_new;
max = max_new;
t = (min + max) / 2;
fprintf(stderr, "Iteration %d. t: %d min: %d (%d) max: %d (%d) delta %d\n", k, t, min, count_min, max, count_max, delta);
k++;
}
for (i = 0; i < 1000; i++) {
if (signal_pulse_data[i][0] > 0) {
//fprintf(stderr, "%d\n", signal_pulse_data[i][1]);
}
}
/* 50% decision limit */
if (min != 0 && max / min > 1) {
fprintf(stderr, "Pulse coding: Short pulse length %d - Long pulse length %d\n", min, max);
signal_type = 2;
} else {
fprintf(stderr, "Distance coding: Pulse length %d\n", (min + max) / 2);
signal_type = 1;
}
p_limit = (max + min) / 2;
/* Initial guesses */
a[0] = 1000000;
a[2] = 0;
for (i = 1; i < 1000; i++) {
if (signal_pulse_data[i][0] > 0) {
// fprintf(stderr, "[%03d] s: %d\t e:\t %d\t l:%d\t d:%d\n",
// i, signal_pulse_data[i][0], signal_pulse_data[i][1],
// signal_pulse_data[i][2], signal_pulse_data[i][0]-signal_pulse_data[i-1][1]);
signal_distance_data[i - 1] = signal_pulse_data[i][0] - signal_pulse_data[i - 1][1];
if (signal_distance_data[i - 1] > a[2])
a[2] = signal_distance_data[i - 1];
if (signal_distance_data[i - 1] <= a[0])
a[0] = signal_distance_data[i - 1];
}
}
min = a[0];
max = a[2];
a[1] = (a[0] + a[2]) / 2;
// for (i=0 ; i<1 ; i++) {
// b[i] = (a[i]+a[i+1])/2;
// }
b[0] = (a[0] + a[1]) / 2;
b[1] = (a[1] + a[2]) / 2;
// fprintf(stderr, "a[0]: %d\t a[1]: %d\t a[2]: %d\t\n",a[0],a[1],a[2]);
// fprintf(stderr, "b[0]: %d\t b[1]: %d\n",b[0],b[1]);
k = 1;
delta = 10000000;
while ((k < 10) && (delta > 0)) {
for (i = 0; i < 3; i++) {
a_new[i] = 0;
a_cnt[i] = 0;
}
for (i = 0; i < 1000; i++) {
if (signal_distance_data[i] > 0) {
if (signal_distance_data[i] < b[0]) {
a_new[0] += signal_distance_data[i];
a_cnt[0]++;
} else if (signal_distance_data[i] < b[1] && signal_distance_data[i] >= b[0]) {
a_new[1] += signal_distance_data[i];
a_cnt[1]++;
} else if (signal_distance_data[i] >= b[1]) {
a_new[2] += signal_distance_data[i];
a_cnt[2]++;
}
}
}
// fprintf(stderr, "Iteration %d.", k);
delta = 0;
for (i = 0; i < 3; i++) {
if (a_cnt[i])
a_new[i] /= a_cnt[i];
delta += (a[i] - a_new[i])*(a[i] - a_new[i]);
// fprintf(stderr, "\ta[%d]: %d (%d)", i, a_new[i], a[i]);
a[i] = a_new[i];
}
// fprintf(stderr, " delta %d\n", delta);
if (a[0] < min) {
a[0] = min;
// fprintf(stderr, "Fixing a[0] = %d\n", min);
}
if (a[2] > max) {
a[0] = max;
// fprintf(stderr, "Fixing a[2] = %d\n", max);
}
// if (a[1] == 0) {
// a[1] = (a[2]+a[0])/2;
// fprintf(stderr, "Fixing a[1] = %d\n", a[1]);
// }
// fprintf(stderr, "Iteration %d.", k);
for (i = 0; i < 2; i++) {
// fprintf(stderr, "\tb[%d]: (%d) ", i, b[i]);
b[i] = (a[i] + a[i + 1]) / 2;
// fprintf(stderr, "%d ", b[i]);
}
// fprintf(stderr, "\n");
k++;
}
if (override_short) {
p_limit = override_short;
a[0] = override_short;
}
if (override_long) {
a[1] = override_long;
}
fprintf(stderr, "\nShort distance: %d, long distance: %d, packet distance: %d\n", a[0], a[1], a[2]);
fprintf(stderr, "\np_limit: %d\n", p_limit);
bitbuffer_clear(&p.bits);
if (signal_type == 1) {
for (i = 0; i < 1000; i++) {
if (signal_distance_data[i] > 0) {
if (signal_distance_data[i] < (a[0] + a[1]) / 2) {
// fprintf(stderr, "0 [%d] %d < %d\n",i, signal_distance_data[i], (a[0]+a[1])/2);
bitbuffer_add_bit(&p.bits, 0);
} else if ((signal_distance_data[i] > (a[0] + a[1]) / 2) && (signal_distance_data[i] < (a[1] + a[2]) / 2)) {
// fprintf(stderr, "0 [%d] %d > %d\n",i, signal_distance_data[i], (a[0]+a[1])/2);
bitbuffer_add_bit(&p.bits, 1);
} else if (signal_distance_data[i] > (a[1] + a[2]) / 2) {
// fprintf(stderr, "0 [%d] %d > %d\n",i, signal_distance_data[i], (a[1]+a[2])/2);
bitbuffer_add_row(&p.bits);
}
}
}
bitbuffer_print(&p.bits);
}
if (signal_type == 2) {
for (i = 0; i < 1000; i++) {
if (signal_pulse_data[i][2] > 0) {
if (signal_pulse_data[i][2] < p_limit) {
// fprintf(stderr, "0 [%d] %d < %d\n",i, signal_pulse_data[i][2], p_limit);
bitbuffer_add_bit(&p.bits, 0);
} else {
// fprintf(stderr, "1 [%d] %d > %d\n",i, signal_pulse_data[i][2], p_limit);
bitbuffer_add_bit(&p.bits, 1);
}
if ((signal_distance_data[i] >= (a[1] + a[2]) / 2)) {
// fprintf(stderr, "\\n [%d] %d > %d\n",i, signal_distance_data[i], (a[1]+a[2])/2);
bitbuffer_add_row(&p.bits);
}
}
}
bitbuffer_print(&p.bits);
}
for (i = 0; i < 1000; i++) {
signal_pulse_data[i][0] = 0;
signal_pulse_data[i][1] = 0;
signal_pulse_data[i][2] = 0;
signal_distance_data[i] = 0;
}
};