misc/adsb-tools
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Switch to overlay parsing.

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This commit is contained in:
Ian Gulliver
2016-02-16 03:26:52 +00:00
parent af8b3d0c4c
commit a1e0e2fe9f
3 changed files with 66 additions and 31 deletions
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91
airspy_adsb.c
View File

@@ -6,11 +6,38 @@
#include "common.h"
#include "airspy_adsb.h"
struct __attribute__((packed)) airspy_adsb_common_overlay {
char mlat_timestamp[8];
char semicolon1;
char mlat_precision[2];
char semicolon2;
char rssi[4];
char semicolon3;
};
struct __attribute__((packed)) airspy_adsb_mode_s_short_overlay {
char asterisk;
char payload[14];
char semicolon;
struct airspy_adsb_common_overlay common;
char cr;
char lf;
};
struct __attribute__((packed)) airspy_adsb_mode_s_long_overlay {
char asterisk;
char payload[28];
char semicolon;
struct airspy_adsb_common_overlay common;
char cr;
char lf;
};
struct airspy_adsb_parser_state {
struct mlat_state mlat_state;
};
static bool airspy_adsb_parse_common(char *, struct packet *, struct airspy_adsb_parser_state *);
static bool airspy_adsb_parse_common(struct airspy_adsb_common_overlay *, struct packet *, struct airspy_adsb_parser_state *);
void airspy_adsb_init() {
@@ -25,41 +52,49 @@ bool airspy_adsb_parse(struct backend *backend, struct packet *packet) {
buf_chr(buf, 0) != '*') {
return false;
}
if (buf->length >= 35 &&
buf_chr(buf, 33) == '\r' &&
buf_chr(buf, 34) == '\n' &&
buf_chr(buf, 15) == ';') {
if (!airspy_adsb_parse_common(buf_at(buf, 16), packet, state)) {
return false;
{
struct airspy_adsb_mode_s_short_overlay *short_overlay = (struct airspy_adsb_mode_s_short_overlay *) buf_at(buf, 0);
if (short_overlay->cr == '\r' &&
short_overlay->lf == '\n' &&
short_overlay->semicolon == ';') {
if (!airspy_adsb_parse_common(&short_overlay->common, packet, state)) {
return false;
}
packet->type = MODE_S_SHORT;
hex_to_bin(packet->payload, short_overlay->payload, sizeof(short_overlay->payload) / 2);
buf_consume(buf, sizeof(*short_overlay));
return true;
}
packet->type = MODE_S_SHORT;
hex_to_bin(packet->data, buf_at(buf, 1), 7);
buf_consume(buf, 35);
return true;
}
if (buf->length >= 49 &&
buf_chr(buf, 47) == '\r' &&
buf_chr(buf, 48) == '\n' &&
buf_chr(buf, 29) == ';') {
if (!airspy_adsb_parse_common(buf_at(buf, 30), packet, state)) {
return false;
{
struct airspy_adsb_mode_s_long_overlay *long_overlay = (struct airspy_adsb_mode_s_long_overlay *) buf_at(buf, 0);
if (buf->length >= 49 &&
long_overlay->cr == '\r' &&
long_overlay->lf == '\n' &&
long_overlay->semicolon == ';') {
if (!airspy_adsb_parse_common(&long_overlay->common, packet, state)) {
return false;
}
packet->type = MODE_S_LONG;
hex_to_bin(packet->payload, long_overlay->payload, sizeof(long_overlay->payload) / 2);
buf_consume(buf, sizeof(*long_overlay));
return true;
}
packet->type = MODE_S_LONG;
hex_to_bin(packet->data, buf_at(buf, 1), 14);
buf_consume(buf, 49);
return true;
}
return false;
}
static bool airspy_adsb_parse_common(char *in, struct packet *packet, struct airspy_adsb_parser_state *state) {
if (in[8] != ';' ||
in[11] != ';' ||
in[16] != ';') {
static bool airspy_adsb_parse_common(struct airspy_adsb_common_overlay *overlay, struct packet *packet, struct airspy_adsb_parser_state *state) {
if (overlay->semicolon1 != ';' ||
overlay->semicolon2 != ';' ||
overlay->semicolon3 != ';') {
return false;
}
uint16_t mlat_mhz = 2 * hex_to_int(&in[9], 1);
packet->mlat_timestamp = mlat_timestamp_scale_in(hex_to_int(in, 4), UINT32_MAX, mlat_mhz, &state->mlat_state);
packet->rssi = rssi_scale_in(hex_to_int(&in[12], 2), UINT16_MAX);
uint16_t mlat_mhz = 2 * hex_to_int(overlay->mlat_precision, sizeof(overlay->mlat_precision) / 2);
packet->mlat_timestamp = mlat_timestamp_scale_in(hex_to_int(overlay->mlat_timestamp, sizeof(overlay->mlat_timestamp) / 2), UINT32_MAX, mlat_mhz, &state->mlat_state);
packet->rssi = rssi_scale_in(hex_to_int(overlay->rssi, sizeof(overlay->rssi) / 2), UINT16_MAX);
return true;
}

2
common.h
View File

@@ -41,7 +41,7 @@ struct packet {
MODE_S_SHORT,
MODE_S_LONG,
} type;
char data[DATA_LEN_MAX];
char payload[DATA_LEN_MAX];
uint64_t mlat_timestamp;
uint32_t rssi;
};

4
json.c
View File

@@ -22,7 +22,7 @@ static size_t json_hello(char *buf) {
static size_t json_serialize_mode_s_short(struct packet *packet, char *buf) {
char hexbuf[14];
hex_from_bin(hexbuf, packet->data, 7);
hex_from_bin(hexbuf, packet->payload, 7);
int len = snprintf(buf, SERIALIZE_LEN,
"{\"payload\":\"%.14s\",\"mlat_timestamp\":%ju,\"rssi\":%ju}\n",
hexbuf,
@@ -34,7 +34,7 @@ static size_t json_serialize_mode_s_short(struct packet *packet, char *buf) {
static size_t json_serialize_mode_s_long(struct packet *packet, char *buf) {
char hexbuf[28];
hex_from_bin(hexbuf, packet->data, 14);
hex_from_bin(hexbuf, packet->payload, 14);
int len = snprintf(buf, SERIALIZE_LEN,
"{\"payload\":\"%.28s\",\"mlat_timestamp\":%ju,\"rssi\":%ju}\n",
hexbuf,