nodemcu-collector

Collect measurements from sensors connected to NodeMCU and transmit them to InfluxDB.

This project is intended as starting point for projects where you have to collect data from a set of sensors connected to ESP8266 and any othe IoT platform that support NodeMCU firmware.

Requirements

• A ESP8266 module or similar
• Knowledge about NodeMCU platform and Lua programming language
• A NodeMCU firmware compiled with these modules at least: bit,dht,file,gpio,i2c,net,node,rtctime,sntp,tmr,uart,wifi . You can compile it easly using http://nodemcu-build.com/
• ESplorer for edit and upload code to the module
• An accessible instance of InfluxDB server

Assumptions

• You want collect data from sensors without interaction
• You need the most fiability as possible. It means support wifi or influxdb shutdowns with minor data loss.
• You supply energy to module using a mini UPS device.

Installation

• Clone or Download this repository
• Edit config.lua and config_local.lua according to your environment
• Upload all these files to NodeMCU module and reset it
• Inspect output of serial console of module, you should see a succesful wifi connection info.
• Start sending basic measurements to InfluxDB, type on console: require('main')
• Check data captured on InfluxDB. You will get these measurements: node_heap, wifi_signal, node_event

Add a Sensor

As an example let's add a DHT temperature and humidiy sensor.

• Modify config.lua

  • Uncomment externalTemp and externalHum lines under readerId array
  • Uncomment influxMeasurement[cfg.readerId.externalTemp] and influxMeasurement[cfg.readerId.externalHum]; these define the data field names in your DB
  • Uncomment captureDelta[cfg.readerId.externalTemp] and captureDelta[cfg.readerId.externalHum]; if your reading does not change by this amount in comparison to the last, it will not be submitted to the DB.

• Modify main.lua

  • Uncomment require('reader_temp_hum'); this includes the script file which contains the function to query the DHT sensor

• Modify pins.lua

  • Ensure the dht pin definition matches up with your hardware (or move your DHT data lead to pin 3)

• Modify read_round.lua

  • Uncomment lines under "-- External temp and humidity"; this will check the last returned value from the sensor and queue it for submission

• Modify reader_slots.lua

  • Uncomment cfg.readerId.externalTemp

That's it, upload the modified files to your NodeMCU, require('main') to execute the main loop and you shoudl start to see DHT sensor values read. To add other types of sensor use the DHT code as a template, modifying to account for the dirrerent way in which your sensor works.

Production Use

To use in anger, ensuring that the collector begins polling sensors and submitting data automatically on power-up, you must set 'cfg.production = true' and 'production = true,' in config_local.lua and config.lua files.