1. I see some garbage on the Serial monitor?

You are probably using a generic ESP8266. The problem with these modules is the built-in LED is tied to the serial line. You can do two things:

  • Disable the serial logging, to have the LED working:

void setup() {
  Homie.enableLogging(false); // before Homie.setup()
  // ...
* Disable the the LED blinking, to have the serial line working:

void setup() {
  Homie.enableBuiltInLedIndicator(false); // before Homie.setup()
  // ...

2. I see an abort message on the Serial monitor?

abort() is called by Homie for ESP8266 when the framework is used in a bad way. The possible causes are:

  • You are calling a function that is meant to be called before Homie.setup(), after Homie.setup()

  • One of the string you've used (in setFirmware(), subscribe(), etc.) is too long. Check the Limits.hpp file to see the max length possible for each string.

3. The network is completely unstable... What's going on?

The framework needs to work continuously (ie. Homie.loop() needs to be called very frequently). In other words, don't use delay() (see avoid delay) or anything that might block the code for more than 50ms or so. There is also a known Arduino for ESP8266 issue with analogRead(), see Limitations and known issues#adc-readings.

4. My device resets itself without me doing anything?

You have probably connected a sensor to the default reset pin of the framework (D3 on NodeMCU, GPIO0 on other boards). See Advanced usage#reset.