Add LoRa telemetry, fault counters, and time sync status

src/time_manager.cpp

@@ -7,6 +7,14 @@
 static bool g_time_synced = false;
 static bool g_tz_set = false;
 static bool g_rtc_present = false;
+static uint32_t g_last_sync_utc = 0;
+
+static void note_last_sync(uint32_t epoch) {
+  if (epoch == 0) {
+    return;
+  }
+  g_last_sync_utc = epoch;
+}
 
 void time_receiver_init(const char *ntp_server_1, const char *ntp_server_2) {
   const char *server1 = (ntp_server_1 && ntp_server_1[0] != '\0') ? ntp_server_1 : "pool.ntp.org";
@@ -24,6 +32,10 @@ uint32_t time_get_utc() {
   if (now < 1672531200) {
     return 0;
   }
+  if (!g_time_synced) {
+    g_time_synced = true;
+    note_last_sync(static_cast<uint32_t>(now));
+  }
   return static_cast<uint32_t>(now);
 }
 
@@ -42,16 +54,17 @@ void time_set_utc(uint32_t epoch) {
   tv.tv_usec = 0;
   settimeofday(&tv, nullptr);
   g_time_synced = true;
+  note_last_sync(epoch);
 
   if (g_rtc_present) {
     rtc_ds3231_set_epoch(epoch);
   }
 }
 
-void time_send_timesync(uint16_t device_id_short) {
+bool time_send_timesync(uint16_t device_id_short) {
   uint32_t epoch = time_get_utc();
   if (epoch == 0) {
-    return;
+    return false;
   }
 
   char payload_str[32];
@@ -60,7 +73,7 @@ void time_send_timesync(uint16_t device_id_short) {
   uint8_t compressed[LORA_MAX_PAYLOAD];
   size_t compressed_len = 0;
   if (!compressBuffer(reinterpret_cast<const uint8_t *>(payload_str), strlen(payload_str), compressed, sizeof(compressed), compressed_len)) {
-    return;
+    return false;
   }
 
   LoraPacket pkt = {};
@@ -70,7 +83,7 @@ void time_send_timesync(uint16_t device_id_short) {
   pkt.payload_type = PayloadType::TimeSync;
   pkt.payload_len = compressed_len;
   memcpy(pkt.payload, compressed, compressed_len);
-  lora_send(pkt);
+  return lora_send(pkt);
 }
 
 bool time_handle_timesync_payload(const uint8_t *payload, size_t len) {
@@ -134,3 +147,18 @@ bool time_try_load_from_rtc() {
 bool time_rtc_present() {
   return g_rtc_present;
 }
+
+uint32_t time_get_last_sync_utc() {
+  return g_last_sync_utc;
+}
+
+uint32_t time_get_last_sync_age_sec() {
+  if (!time_is_synced()) {
+    return 0;
+  }
+  if (g_last_sync_utc == 0) {
+    return 0;
+  }
+  uint32_t now = time_get_utc();
+  return now > g_last_sync_utc ? now - g_last_sync_utc : 0;
+}