My LORA remote relay system

Description:

After having installed and setup my 15kw hybrid solar system with emoncms,

my next step is to develop and install a remote switches system to be able to remotely control 9 units of 4 relays each.

Each unit consist of one bungalow with

    • 1 220V line for the bungalow lights and outlets.

    • 1 220V line for the fridge

    • 1 220V line for the outside spot light

    • 1 220V line for the garden lamps

I need to remotely switch On and Off the fridge and the bungalow when the cottage is unoccupied or with some guest but without minibar option.

I want to switch On and Off the outside spot light and the garden light on time based with a timer to automatically switch on some of them at a certain time.

Due to the distance in between each bungalows and the central building deploying a WiFi network or Ethernet network would have required multiple hops and would have been over-killed to just transmit simple command to each unit. If a Wifi or Ethernet network would have been already installed, i would have probably use it to interconnect each unit.

LORA was then the obvious choice to interconnect my units to a central remote switch. Not LORA Wan but just simple LORA connection by using the RFM95 module on the 900Mhz band (authorized band in the country where the system is setup) and the Radiohead libray by airspayce.

Requirement:

    • The relays should work in NC mode (normally closed). If the system is Off, all the contact are closed and everything powered.

    • Max 5A per relay

    • The system must have multiple interface:

    • Direct with LCD screen Rotary encoder and button switch

    • Via The serial port and a serial monitor

    • Via HTTP with embedded HTTP server on the monitor

    • Via node-RED and MQTT

  • Must synchronized time from NTP, save it on RTC module and serve it via http request

  • Must be able to switch ON/OFF generator on demand or time limit.

  • Monitor must be redundant in case of one monitor failure.

Diagram: