ESP8266 MQTT Wifi Client to Serial Bridge with NTP

by rkubera (Radek Kubera) https://github.com/rkubera

• License: MIT

Features

• WEB GUI Configuration Interface
• Connect to MQTT Server via WIFI
• Publish Topics to MQTT Server via UART (Serial port)
• Subscribe/Unsubscribe Topics from MQTT Server via UART
• Automaticaly reconnect to Wifi if signal lost
• Automaticaly reconnect to MQTT Server and resubscribe Topics if disconnected
• Automaticaly get NTP time
• Easy API
• CRC32 checksums

Connection

Connect do ESP8266 via UART port (9600 baudrate)

GUI

You can configure ssid, password and mqtt parameters via web GUI. If ESP8266 cannot connects to WIFI Acces Point, creates own WIFI Acces Point named mqtt-clnt-XXXXXXXX (where XXXXXXX is Chip SN) You can connect to AP and open Web Browser with address: http://192.168.4.1 Now you can set all parameters and save configuration. If ESP8266 connects successfully to WIFI Acces Point, Web Server will stopped. You can alsow modify all settings via API inerface (using UART port).

API

All responses starts with crc32 checksum (if CRC32 is enabled), for example:

• 1426454121 [connecting to wifi]

In commands description crc32 checksum will be represented as CRC32 (if CRC32 is enabled) for eample:

• CRC32 [connecting to wifi]

Commands (must be finished with \n EOL):

1. connect

• Connect to open accespoint myAccesspoint
  • command: connect myAccespoint
  • response1 (on start): CRC32 [conecting to wifi]
  • response2 (on success): CRC32 [wifi connected]
• Connect to accespoint myAccesspoint with myPassword
  • command: connect myAccespoint:myPassword
  • response1 (on start): CRC32 [conecting to wifi]
  • response2 (on success): CRC32 [wifi connected]

2. mqttuserpass

• Set Mqtt Server user mymqttuser with empty pass
  • command: mqttuserpass mymqttuser
  • response: CRC32 [mqtt user and pass set]
• Set Mqtt Server user mymqttuser with password mymqttpass
  • command: mqttuserpass mymqttuser:mymqttpass
  • response: CRC32 [mqtt user and pass set]

3. mqttserver

• Set Mqtt Server mqttserver mymqttserver only (port will be set as Default:1883)
  • command: mqttserver mymqttserver
  • response1 (on start): CRC32 [connecting to mqtt server]
  • response2 (on success): CRC32 [mqtt connected]
• Set Mqtt Server mqttserver mymqttuser and mqttport 1885
  • command: mqttserver mymqttserver:1885
  • response1 (on start): CRC32 [connecting to mqtt server]
• response2 (on success): CRC32 [mqtt connected]

4. publish and publishretained

• Publish topic mytopic with payload mypayload:
  • command: publish mytopic mypayload
  • response: CRC32 [published] or CRC32 [wrong publish command] or CRC32 [mqtt not connected]
• Publish retained topic mymtopic with payload mypayload:
  • command: publishretained mytopic mypayload
  • response: CRC32 [published] or CRC32 [wrong publish command] or CRC32 [mqtt not connected]

5. subscribe and unsubscribe

• Subsctibe topic mytopic
  • command: subscribe mytopic
  • response: CRC32 [subscription added] or CRC32 [mqtt not connected]
• Unsubscribe topic mytopic
  • command: unsubscribe mytopic
  • response: CRC32 [subscription removed] or CRC32 [mqtt not connected]

6. crc32

• Enable CRC32 checksum (default)
  • command: crc32 on
  • response: CRC32 [crc32 on]
• Disable CRC32 checksum
  • command: crc32 off
  • response: [crc32 off]

7. hostname

• Change hostname
  • command: hostname myhostname
  • response: CRC32 [hostname myhostname]

8. get

• Get timestamp from NTP (UTC+0)
  • command: get timestamp
  • response: CRC32 [timestamp 1131334556] or CRC32 [timestamp 0] if not connected to NTP server (yet)
• Get echo (check if ESP8266 is live)
  • command: get echo
  • response: CRC32 [echo]
• Get ip address
  • command: get ip
  • response: CRC32 [123.123.123.123]
• Get WiFi status
  • command: get wifistatus
  • response: CRC32 [wifi connected] or [wifi not connected]
• Get ssid
  • command: get ssid
  • resonse: CRC32 [ssid myssid]
• Get MQTT Server status
  • command: get mqttstatus
  • response: CRC32 [mqtt connected] or CRC32 [mqtt not connected]
• Get mqtt Server
  • comand: get mqttserver
  • response: CRC32 [mqttserver mymqttserver]
• Get mqtt user
  • command: get mqttuser
  • response: CRC32 [mqttuser mymqttuser]
• Get mqtt hostname
  • command: get hostname
  • response: CRC32 [hostname mymqtthostname]
• Get CRC32 checksum status
  • command: get crc32status
  • response: crc32 on/crc32 off

9. errors if ESP8266 not recognised command will return [error] message.

Quck example:

• Send: connect mywifi:mypass
• Recv: 1426454121 [connecting to wifi]
• Recv: 3286076215 [wifi connected]
• Send: mqttuserpass mymqttuser:mymqttpass
• Recv: 504100829 [mqtt user and pass set]
• Send: mqttserver mymqtt
• Recv: 3239127883 [connecting to mqtt server]
• Recv: 4088902839 [mqtt connected]
• Send: subscribe espMessages/#
• Recv: 294403144 [subscription added]
• Send: crc32 off
• Recv: [crc32 off]
• Send: publish espMessages/test Hello World!
• Recv: [published]
• Recv: espMessages/test Hello World!
• Send: get timestamp
• Recv: [timestamp 1554581454]