Trying to learn esp8266 module to communacate with MQTT broker.

• paho.mqtt.testing broker(https://github.com/eclipse/paho.mqtt.testing)

• use AT command to setting flow control on AT command may need to flash new firmware. https://arduino.stackexchange.com/questions/45188/esp8266-01-wrong-flow-control-settings
• Playing With a ESP8266 WiFi Module https://williamdurand.fr/2015/03/17/playing-with-a-esp8266-wifi-module/ ESP8266_AT firmware https://github.com/espressif/esp8266_at/tree/master/bin
• using arduino to flash firmware(This one solve my problem after 2 hour struggling with flashing on ubuntu I change to Windows. It's solve my problem in about 10 minute.) https://www.youtube.com/watch?v=Ag_Yk_0AFxs