Intro

In post #7 I briefly introduced LoRa. The first logical project for me was to try and see how long I can reach using these promising modules! So, I started working on this Project.

The end platform comprises of a base-station and as many portable nodes. The base station uses the NRF24 mesh network I talked about in post #4 to log received communications and its activity through a Node-Red follow into an influxDB timeseries data base.

At first, I started with the Arduino pro mini 3.3 8HZ, ATMEGA 168.

As it does not have a usb port, it needs to press the reset button on the board before uploading a sketch. At the end by adding other necessary libraries, the board did not have enough memory and I had to switch to ATMEGA 238 for both base station and portable device.

For the first trial, the system comprises of two devices: a base-station located at my house balcony listening for incoming messages and a portable device with GPS sending its location and listening for any message.

Base-Station

Based on Stuart Robinson library, LoRa tracker, I decided to create one device and use my home fixed lat and log and have the device transmit it every X second. I will use the second portable device as a receiver. The main reason was to not have two devices need GPS.

Later I added the receiving feature to the transmitter. I grabbed the receiver code from Stuart and added it to my code. [right now, it is receiving messages from LoRa GPS tracker transmitter, I need to generalize it so it will receive any message)

I added MQTT and MySensors capability to my station so basically it would be a LoRa base station, transmitting my location and receiving any messages it receives.

MySensors is added successfully, in order to do so [having two SPI devices] I needed to change the reset and cs[nss] pin of the LoRa library because NRF24 [the communication module] is using those.

The base station is connected through MQTT / MySensors via a NRF24 mesh network to my Node-Red backend that parses and logs all incoming traffic to my InfluxDB data centre and a Grafana web interface displays the information. It has a battery monitoring system which monitors and sends the battery level to the data base. It also sends all incoming traffic (i.e. GPS coordinates, RSSI and SNR) to the data base.

in order to install the station on my balcony, I am using a weather sealed enclosure.

Some corner cuts were necessary to fit everything into the box!

Portable node