why is Esp 8826 mqtt example given in arduino ide not able to connect to Mosquito broker.
using mqtt with esp8826 from example code in arduino ide mosquito broker running on droplet properly but gives following message from esp 8826 ( Attempting MQTT connection...failed, rc=-4 try again in 5 seconds )
not able to resolve this for some reason
Have you opened the firewall to allow connections from outside to MQTT?
Did you follow this guide? Or how did you setup Ubuntu with MQTT?
https://www.digitalocean.com/community/tutorials/how-to-install-and-secure-the-mosquitto-mqtt-messaging-broker-on-ubuntu-16-04