prevent watchdog from killing while printing json

src/main.cpp

@@ -87,6 +87,8 @@ static uint16_t g_inflight_batch_id = 0;
 static bool g_inflight_active = false;
 static uint32_t g_last_debug_log_ms = 0;
 
+static void watchdog_kick();
+
 static void serial_debug_printf(const char *fmt, ...) {
   if (!SERIAL_DEBUG_MODE) {
     return;
@@ -99,6 +101,25 @@ static void serial_debug_printf(const char *fmt, ...) {
   Serial.println(buf);
 }
 
+static void serial_debug_print_json(const String &json) {
+  if (!SERIAL_DEBUG_MODE || !SERIAL_DEBUG_DUMP_JSON) {
+    return;
+  }
+  const char *data = json.c_str();
+  size_t len = json.length();
+  const size_t chunk = 128;
+  for (size_t i = 0; i < len; i += chunk) {
+    size_t n = len - i;
+    if (n > chunk) {
+      n = chunk;
+    }
+    Serial.write(reinterpret_cast<const uint8_t *>(data + i), n);
+    watchdog_kick();
+    delay(0);
+  }
+  Serial.write('\n');
+}
+
 static uint16_t g_last_batch_id_rx[NUM_SENDERS] = {};
 
 struct BatchRxState {
@@ -376,7 +397,7 @@ static bool send_inflight_batch(uint32_t ts_for_display) {
   }
   if (SERIAL_DEBUG_MODE) {
     serial_debug_printf("tx: batch_id=%u count=%u json_len=%u", g_inflight_batch_id, g_inflight_count, static_cast<unsigned>(json.length()));
-    Serial.println(json);
+    serial_debug_print_json(json);
   }
 
   static uint8_t compressed[BATCH_MAX_COMPRESSED];