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ADS-B TX works well enough for dump1090 and gr-air-modes

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Hooked ADS-B RX to baseband instead of debug IQ file, not tested
This commit is contained in:
furrtek 2017-07-23 12:20:32 +01:00
parent b57b41753f
commit 5a67a7080a
23 changed files with 949 additions and 437 deletions
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101
firmware/baseband/proc_adsbtx.cpp
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@ -32,26 +32,29 @@ void ADSBTXProcessor::execute(const buffer_c8_t& buffer) {
// This is called at 4M/2048 = 1953Hz
// One pulse = 500ns = 2 samples
// One bit = 2 pulses = 1us = 4 samples
// Test this with ./dump1090 --freq 434000000 --gain 20
// Or ./dump1090 --freq 434000000 --gain 20 --interactive --net --net-http-port 8080 --net-beast
if (!configured) return;
for (size_t i = 0; i < buffer.count; i++) {
if (active) {
if (!sample) {
sample = 3;
if (preamble) {
if (bit_pos >= 16) {
preamble = false;
bit_pos = 0;
} else {
cur_bit = (preamble_parts << bit_pos) >> 15;
bit_pos++;
}
}
if (!preamble) {
/*if (terminate) {
for (size_t i = 0; i < buffer.count; i++) {
buffer.p[i] = { 0, 0 };
}
terminate--;
if (!terminate) {
message.done = true;
shared_memory.application_queue.push(message);
configured = false;
return;
}
} else {*/
for (size_t i = 0; i < buffer.count; i++) {
/*if (active) {
if (!sample) {
sample = 300;
if (bit_pos >= 112) {
active = false; // Stop
cur_bit = 0;
@ -59,38 +62,39 @@ void ADSBTXProcessor::execute(const buffer_c8_t& buffer) {
cur_bit = shared_memory.bb_data.data[bit_pos];
bit_pos++;
}
} else
sample--;
if (!preamble) {
if (sample == 150)
cur_bit ^= 1; // Invert
}
} else
sample--;
} else {*/
/*cur_bit = 0;
if (bit_pos >= 16384) {
configured = false;
message.done = true;
shared_memory.application_queue.push(message);
}*/
if (bit_pos >= (240 << 1)) {
configured = false;
terminate = 100;
cur_bit = 0;
} else {
cur_bit = shared_memory.bb_data.data[bit_pos >> 1];
bit_pos++;
}
//}
if (sample == 1)
cur_bit ^= 1; // Invert
} else {
//cur_bit = 0;
if (bit_pos == 8192) { // ?
configured = false;
message.done = true;
shared_memory.application_queue.push(message);
if (cur_bit) {
// Crude AM
buffer.p[i] = am_lut[phase & 3];
phase++;
} else {
buffer.p[i] = { 0, 0 };
}
bit_pos++;
}
delta = tone_sample * fm_delta;
tone_sample += 128;
if (cur_bit) {
phase += delta;
sphase = phase + (64 << 24);
re = (sine_table_i8[(sphase & 0xFF000000U) >> 24]);
im = (sine_table_i8[(phase & 0xFF000000U) >> 24]);
} else {
re = 0;
im = 0;
}
buffer.p[i] = {re, im};
}
//}
}
void ADSBTXProcessor::on_message(const Message* const p) {
@ -98,13 +102,10 @@ void ADSBTXProcessor::on_message(const Message* const p) {
if (message.id == Message::ID::ADSBConfigure) {
bit_pos = 0;
sample = 0;
cur_bit = 0;
preamble = true;
phase = 0;
active = true;
configured = true;
fm_delta = 50000 * (0xFFFFFFULL / 4000000); // Fixed bw for now
terminate = 0;
}
}