From 69c4f9f7fcc2027731283b4fe8f7b8f3967408a1 Mon Sep 17 00:00:00 2001
From: Carles Fernandez <carles.fernandez@gmail.com>
Date: Fri, 22 Oct 2021 15:51:38 +0200
Subject: [PATCH] Remove redundant fields in an_packet_t

---
 src/algorithms/PVT/libs/an_packet_printer.cc | 18 +++++++++---------
 src/algorithms/PVT/libs/an_packet_printer.h  |  6 ++----
 2 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/src/algorithms/PVT/libs/an_packet_printer.cc b/src/algorithms/PVT/libs/an_packet_printer.cc
index 5ee613943..72e7e8a9f 100644
--- a/src/algorithms/PVT/libs/an_packet_printer.cc
+++ b/src/algorithms/PVT/libs/an_packet_printer.cc
@@ -98,6 +98,7 @@ void An_Packet_Printer::update_sdr_gnss_packet(sdr_gnss_packet_t* _packet, const
     uint8_t num_gps_sats = 0;
     uint8_t num_gal_sats = 0;
     int index = 0;
+    bool fix_3d = pvt->is_valid_position();
     const int max_reported_sats = *(&_packet->sats + 1) - _packet->sats;
 
     for (gnss_observables_iter = gnss_observables_map.cbegin();
@@ -178,8 +179,10 @@ void An_Packet_Printer::update_sdr_gnss_packet(sdr_gnss_packet_t* _packet, const
     _packet->velocity[2] = static_cast<float>(-pvt->get_rx_vel()[2]);
 
     uint16_t status = 0;
-    // Set 3D fix (bit 0 and 1) / Set Doppler velocity valid (bit 2) / Set Time valid (bit 3)
-    status = status & 0b00001111;
+    if (fix_3d)
+        {
+            status = 15;  // Set 3D fix (bit 0 and 1) / Set Doppler velocity valid (bit 2) / Set Time valid (bit 3)
+        }
     _packet->status = status;
 }
 
@@ -192,8 +195,6 @@ void An_Packet_Printer::update_sdr_gnss_packet(sdr_gnss_packet_t* _packet, const
  */
 void An_Packet_Printer::encode_sdr_gnss_packet(sdr_gnss_packet_t* sdr_gnss_packet, an_packet_t* _packet) const
 {
-    _packet->id = SDR_GNSS_PACKET_ID;
-    _packet->length = SDR_GNSS_PACKET_LENGTH;
     uint8_t offset = 0;
     LSB_bytes_to_array(reinterpret_cast<uint8_t*>(&sdr_gnss_packet->nsvfix), offset, _packet->data, sizeof(sdr_gnss_packet->nsvfix));
     offset += sizeof(sdr_gnss_packet->nsvfix);
@@ -238,10 +239,9 @@ void An_Packet_Printer::encode_sdr_gnss_packet(sdr_gnss_packet_t* sdr_gnss_packe
 void An_Packet_Printer::an_packet_encode(an_packet_t* an_packet) const
 {
     uint16_t crc;
-    an_packet->header[1] = an_packet->id;
-    an_packet->header[2] = an_packet->length;
-    crc = calculate_crc16(an_packet->data, an_packet->length);
-    memcpy(&an_packet->header[3], &crc, sizeof(uint16_t));
+    an_packet->header[1] = SDR_GNSS_PACKET_ID;
+    crc = calculate_crc16(an_packet->data, SDR_GNSS_PACKET_LENGTH);
+    memcpy(&an_packet->header[2], &crc, sizeof(uint16_t));
     an_packet->header[0] = calculate_header_lrc(&an_packet->header[1]);
 }
 
@@ -251,7 +251,7 @@ void An_Packet_Printer::an_packet_encode(an_packet_t* an_packet) const
  */
 uint8_t An_Packet_Printer::calculate_header_lrc(const uint8_t* data) const
 {
-    return ((data[0] + data[1] + data[2] + data[3]) ^ 0xFF) + 1;
+    return ((data[0] + data[1] + data[2]) ^ 0xFF) + 1;
 }
 
 
diff --git a/src/algorithms/PVT/libs/an_packet_printer.h b/src/algorithms/PVT/libs/an_packet_printer.h
index 596c33f26..f9b96a46a 100644
--- a/src/algorithms/PVT/libs/an_packet_printer.h
+++ b/src/algorithms/PVT/libs/an_packet_printer.h
@@ -61,10 +61,8 @@ struct sdr_gnss_packet_t
 
 struct an_packet_t
 {
-    uint8_t id;
-    uint8_t length;
-    uint8_t header[5];  // AN_PACKET_HEADER_SIZE
-    uint8_t data[126];  // AN_MAXIMUM_PACKET_SIZE
+    uint8_t header[4];
+    uint8_t data[73];  // SDR_GNSS_PACKET_LENGTH
 };