Aart MQTT notes

These are my personal notes & developments; any opinion expressed on this page is just that :-)

MQTT on Wifi Principals

• assume no privacy
• Use short, systematic but human readable topics and messages. Using a room number in common use is fine, an eight byte digital address is not. Use standard units and formatting (e.g. aart/kitchen/temperature 17,2 )
• Minimize the amount of wires, use more nodes if required
• Hardware- and MQTT configurations are managed in the source for now, as nodes tend to be all different. Counter offsets can be set after a power up by posting on MQTT.

ESP8266 Node firmware development

Makerspace Leiden workshop op 23-01-2017

ESP Boards

• Wemos D1 mini

Sensors

Links

Use proven test programs & setups to test the sensors, hardware and Wifi / MQTT setup before putting it all together.

Links to datasheets, standard libraries & examples of sensors i use; use the Arduino library manager to get these:

• DS18S20 One-wire thermometer. Datasheet OneWire
• Neopixel leds: Datasheet FastLED library
• HIH6030 i2c temperature & humidity. Datasheet Honeywell HIH library
• Senseair K30 CO2 sensor Datasheet
• MQTT: Adafruit library

My own code

• Non blocking Single DS reader demo
• Non blocking gasMeter demo
• Non blocking Multiple DS reader demo
• HIH6030 reading routines HIH6030 demo
• Thermal voltage sensor demo

Pi3B Broker

Makerspace Leiden workshop on 27-02-2017

Raspbian

• Download: Raspbian lite
• Install on SD card following the instructions

Using a serial console

• add line "enable_uart=1" at the end of /boot/config.txt
• Pins: GPIO 6 gnd, 8 Pi Txd, 10 Pi RxD - 3V3 logic levels (!)
• Speed: 115200

Update

Run:

• apt update
• apt -y upgrade

Configure WLAN as accespoint & build a bridge

hostapd