mDNS sudden death #7262
Description
MCVE:
Simple WiFiSTA + mDNS, and LED blink as coalmine canary :)
- Hardware: [Generic ESP8266 (ESP-WROOM-02 breakout PCB w/DTR reset circuitry)]
- Core Version: commit 4e3a4b6 (latest @ the moment)
- [Edited 3] CPU Frequency: 160 MHz
- [Edited 3] lwIP Variant: v2 Lower Memory (no features)
- [Edited 2] Espressif FW: nonos-sdk 2.2.1+119 (191122)
#include <ESP8266WiFi.h> #include <ESP8266mDNS.h> #define AP_SSID "YOUR-SSID" #define AP_PASSWORD "YOUR-PASSWORD" #define MDNS_HOSTNAME "WiFiSta" #define LED_PIN 4 #define DIVIDER 10000 void setup() { pinMode(LED_PIN, OUTPUT); WiFi.persistent(false); WiFi.mode(WIFI_OFF); Serial.begin(115200); delay(250); WiFi.mode(WIFI_STA); Serial.print(F("\n\n\n" "WiFi(STA): SSID=\"" AP_SSID "\".\n" "WiFi(STA): connecting")); WiFi.begin(F(AP_SSID), F(AP_PASSWORD)); for (; ; delay(500)) { if (WiFi.status() == WL_CONNECTED) { Serial.printf_P(PSTR(", done.\n" "WiFi(STA): IP address=%s/%s.\n" "mDNS: hostname=\"" MDNS_HOSTNAME ".local\".\n"), WiFi.localIP().toString().c_str(), WiFi.subnetMask().toString().c_str()); MDNS.begin(F(MDNS_HOSTNAME)); break; } Serial.print('.'); } } void loop() { MDNS.update(); // visible canary static unsigned int counter = DIVIDER; if (--counter == 0) { counter = DIVIDER; digitalWrite(LED_PIN, digitalRead(LED_PIN) == 0); } }Symptom:
- After WiFi connecting done, 1st mDNS response will almost always be fine.
- But later attempts will not often be responded without any signs, especially at some interval (a few minites~).
- [Edited 1] Once happened, it seems not to recover permanently.
Additional Info:
- Regardless of above, LED blink doesn't stop (
loop()lives). - Same as above, ping w/dot-decimal-notation responds (both WiFi and IP echo live).
- Debug output (eg.
CORE+WIFI+HTTP_UPDATE+UPDATER+OTA+OOM+MDNS) tells no clue about this...