portapack-mayhem/mayhem-firmware
1
0
Fork 0
mirror of https://github.com/portapack-mayhem/mayhem-firmware.git synced 2026-09-11 17:19:29 +00:00
Code Issues Packages Projects Releases 10 Wiki Activity

EPIRB TX application update (#3120)

Browse Source
This commit is contained in:
Frederic BORRY
2026-04-03 11:35:46 +02:00
committed by GitHub
parent 605c9efa0c
commit 03131c8a0c
4 changed files with 273 additions and 45 deletions
Download Patch File Download Diff File Expand all files Collapse all files
firmware/baseband/proc_epirb_tx.cpp
+6 -6
View File
@@ -46,15 +46,15 @@ void EPIRBTXProcessor::execute(const buffer_c8_t& buffer) {
if (mode_bpsk) {
// BPSK Manchester beacon signal
if (bpsk_pre_count < config_pre_count) {
// Pre-count state: send a negative phase carrier during pre-count
// Pre-count state: send carrier only during pre-count
bpsk_pre_count++;
re = i_neg;
im = q_neg;
re = i_carrier;
im = q_carrier;
} else if (bpsk_post_count > 0) {
// Post-count: send a negative phase carrier during post-count
// Post-count: send carrier only during post-count
bpsk_post_count++;
re = i_neg;
im = q_neg;
re = i_carrier;
im = q_carrier;
if (bpsk_post_count >= config_post_count) {
// End transmission here
byte_index = 0;
firmware/baseband/proc_epirb_tx.hpp
+5 -2
View File
@@ -60,14 +60,17 @@ class EPIRBTXProcessor : public BasebandProcessor {
// Size of the frame to send in BPSK mode
uint8_t frame_data_len = 0;
// BPSK parameters: Target phase +/-63° as per COSPAS/SARSAT specifications
static constexpr float phase_rad = 63.0f * M_PI / 180.0f;
// BPSK parameters: Target phase +/-1.1 RAD as per COSPAS/SARSAT specifications
static constexpr float phase_rad = 1.1f;
// I/Q values for BPSK (positive phase and negative phase)
int8_t i_pos = (int8_t)(cos(phase_rad) * 127);
int8_t q_pos = (int8_t)(sin(phase_rad) * 127);
int8_t i_neg = i_pos;
int8_t q_neg = -q_pos;
// I/Q values for carrier only
static constexpr int8_t i_carrier = 127;
static constexpr int8_t q_carrier = 0;
// COSPAS/SARSAT signal is manchester (2 states per bit) encoded 400 bit/sec
static const uint32_t samples_per_halfbit = TONES_SAMPLERATE / 400 / 2;