Current announce cycle was: once per minute, at 2 + NODE_SLOT_INDEX * 4 seconds. So BOB at :06, CY at :10, DAN at :14, etc.

I changed it to:

first announce: immediately after startup once microReticulum is ready
second announce: after ANNOUNCEMENT_2 seconds
later announces: every ANNOUNCEMENT_REPEAT seconds

exercises/204_established_identities/platformio.ini

@@ -55,6 +55,8 @@ build_flags =
   -D MR_TRANSPORT_PROBE=1
   -D MR_LINKFWD_DELAY_MS=750
   -D MR_LRPROOF_DELAY_MS=750
+  -D ANNOUNCEMENT_2=300
+  -D ANNOUNCEMENT_REPEAT=3600
 ; Live announces are enough for this single-hop field exercise. Do not define
 ; RNS_PERSIST_PATHS here: the LittleFS-backed path_store compactor can leave an
 ; active segment FD open while unlinking /path_store_*.dat on ESP32.

exercises/204_established_identities/scripts/pull_build_from_ryzdesk.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+# $Header$
+# $HeadURL$
+
+set -e
+
+EXERCISE="/usr/local/src/microreticulum/microReticulumTbeam/exercises/204_established_identities"
+
+for env in amy bob cy dan ed flo guy
+do
+    ENV="$(echo "$env" | tr '[:lower:]' '[:upper:]')"
+
+    echo "===== copy artifact $env from ryzdesk ====="
+    rsync -a \
+      "ryzdesk:${EXERCISE}/.pio/build/${env}/" \
+      "${EXERCISE}/.pio/build/${env}/"
+
+    echo "===== upload $env / $ENV ====="
+    pio run \
+      -d "$EXERCISE" \
+      -e "$env" \
+      -t nobuild \
+      -t upload \
+      --upload-port "/dev/ttyt${ENV}"
+done

exercises/204_established_identities/src/main.cpp

@@ -49,6 +49,12 @@
 #ifndef MR_LINKFWD_DELAY_MS
 #define MR_LINKFWD_DELAY_MS 0
 #endif
+#ifndef ANNOUNCEMENT_2
+#define ANNOUNCEMENT_2 300
+#endif
+#ifndef ANNOUNCEMENT_REPEAT
+#define ANNOUNCEMENT_REPEAT 3600
+#endif
 
 static constexpr const char* APP_NAME = "microreticulum";
 static constexpr const char* APP_ASPECT = "linkping";
@@ -62,6 +68,8 @@ static constexpr uint32_t LINK_RETRY_MS = 90000;
 static constexpr uint32_t LINK_RX_STALE_MS = 75000;
 static constexpr uint32_t LINK_REOPEN_DELAY_MS = 5000;
 static constexpr uint8_t LINK_MESSAGES_PER_CYCLE = 5;
+static constexpr uint32_t ANNOUNCEMENT_2_MS = (uint32_t)ANNOUNCEMENT_2 * 1000UL;
+static constexpr uint32_t ANNOUNCEMENT_REPEAT_MS = (uint32_t)ANNOUNCEMENT_REPEAT * 1000UL;
 
 struct DateTime {
   uint16_t year = 0;
@@ -614,10 +622,6 @@ static uint8_t node_send_slot_second() {
   return (uint8_t)(4U + ((uint8_t)NODE_SLOT_INDEX * 4U));
 }
 
-static uint8_t node_announce_slot_second() {
-  return (uint8_t)(2U + ((uint8_t)NODE_SLOT_INDEX * 4U));
-}
-
 static int find_peer_by_label(const String& label) {
   for (uint8_t i = 0; i < MAX_PEERS; ++i) {
     if (peers[i].label == label) {
@@ -920,6 +924,9 @@ static void print_config() {
                 (int)NODE_SLOT_INDEX,
                 (int)EX204_RNS_TRACE,
                 (unsigned)MR_LINKFWD_DELAY_MS);
+  Serial.printf("Announce: startup=1 second=%lu repeat=%lu seconds\r\n",
+                (unsigned long)ANNOUNCEMENT_2,
+                (unsigned long)ANNOUNCEMENT_REPEAT);
 }
 
 static void send_announce() {
@@ -931,6 +938,35 @@ static void send_announce() {
   inbound_destination.announce(RNS::bytesFromString(NODE_LABEL));
 }
 
+static void maybe_send_scheduled_announce() {
+  if (!clock_ready || !inbound_destination) {
+    return;
+  }
+
+  static bool startup_announce_sent = false;
+  static uint8_t announce_count = 0;
+  static uint32_t next_announce_ms = 0;
+
+  const uint32_t now = millis();
+  if (!startup_announce_sent) {
+    startup_announce_sent = true;
+    announce_count = 1;
+    next_announce_ms = now + ANNOUNCEMENT_2_MS;
+    send_announce();
+    return;
+  }
+
+  if ((int32_t)(now - next_announce_ms) < 0) {
+    return;
+  }
+
+  send_announce();
+  if (announce_count < 2) {
+    announce_count = 2;
+  }
+  next_announce_ms = now + ANNOUNCEMENT_REPEAT_MS;
+}
+
 static void maybe_open_link(const DateTime& rtc_now, bool have_rtc_now) {
   const uint32_t now = millis();
   static uint32_t last_open_ms = 0;
@@ -1114,7 +1150,6 @@ void loop() {
   static uint32_t last_rtc_poll_ms = 0;
   static DateTime rtc_now{};
   static bool have_rtc_now = false;
-  static uint8_t last_announce_minute = 255;
   uint32_t now = millis();
 
   if ((uint32_t)(now - last_rtc_poll_ms) >= 200U) {
@@ -1123,11 +1158,7 @@ void loop() {
   }
   maybe_open_link(rtc_now, have_rtc_now);
 
-  if (have_rtc_now && rtc_now.second == node_announce_slot_second() &&
-      last_announce_minute != rtc_now.minute) {
-    last_announce_minute = rtc_now.minute;
-    send_announce();
-  }
+  maybe_send_scheduled_announce();
   const uint8_t send_slot = node_send_slot_second();
   const uint8_t second_slot = (uint8_t)((send_slot + 30U) % 60U);
   if (have_rtc_now && (rtc_now.second == send_slot || rtc_now.second == second_slot)) {