Lora and the Things Network

Looking at helping setup some sensors in more remote “green spaces” and was looking at lora and The Things Network…

Anyone had any experience and is the data transmitted within the daily limits of the things network.

I don’t know if it is still up to date but it is worth a try:
https://www.thethingsnetwork.org/labs/story/reporting-pm25-pm10-micro-particle-dust-sensor-by-using-arduino-and-lorawan-atim-acw-duino-shield
Look on the left, there are different sections.

1 Like

And this: https://www.thethingsnetwork.org/forum/t/connection-from-ttn-node-to-luftdaten-api/33073/5

1 Like

Thanks for the reply, I’m looking more along the lines of ESP8266 code, my coding is a bit rusty but I’ve designed a board that has a ESP-12F and a RFM95W for the transmission.

IMG_20201227_1159071|666x500

Will have a look at this code and see what I can do. !

We have some experience with LoRaWAN solutions in Poland. Open Things Network (Otwarta Sieć Rzeczy - https://otwartasiecrzeczy.org/) have solution based on LoRa32u4 II board - documentation in Polish.

Right now we are also working on battery powered sensor based on Heltec CubeCell HTCC-AB01 - Low power mode with SDS011 and BME280 powered only by solar panel. Prototypes are working fine.

1 Like

Still have reservations about some of these boards as they are only prototype devices. The power consumption of the board doesn’t add up and how can it power a 5V device?

In HTCC-AB01 we use step-up boost converter.

I have developed a LoRaWAN particulate matter sensor, it uses the SDS011 and a BME280.
The processor board is an ESP32 + LoRaWAN + display board, can be either the TTGO LoRa board, or the Heltec LoRa board.

Details can be found at:

A tricky thing with TheThingsNetwork is that it has a fair-use policy, you can spend up to 30 seconds of transmissions time per day to send data. The transmission speed is automatically governed through the network, based on how well the node is received. So if you have good coverage, the transmission speed is high and you can stay within the 30 seconds limit even when sending a message every 5 minutes. If the coverage is not so good, transmission speed will be lower and you will exceed the 30 second/day FUP.

My node tries to stay within the FUP by throttling the transmission interval. So close to a gateway (SF7 of SF8) it will send once every 5 minutes. Farther away from a gateway, the transmission interval will be doubled (10 minutes, 20 minutes, 40 minutes), depending on the transmission speed (SF9, SF10, SF11, SF12).

Another thing is a common binary payload format. At this moment, there is none. My node uses the “Cayenne LPP” format, which is reasonably compact, at least it is a kind of standard format. Other implementations all seem to use their own custom format.

Data is picked up from TheThingsNetwork and processed by a Java application that I wrote. It parses the particulate matter data and forwards it to sensor.community and opensensemap.org.
If there was some kind of agreed format, it would also be possible to create a “TTN integration”, that would take over the role of my “forwarder”-application.

There are a couple of prototypes of my nodes running already.

2 Likes

I suppose the other option is to use the Lora to communicate with a custom gateway that will just forward data on, with this?

Only if you use Adaptive Data Rate. You can manually set SF to lower value and add an antenna with better gain. I typically use cheap 2dBi antennas which I modify to achieve VSWR around 1.2. A good VNA like N1201SA is very helpful in this process.

Also it’s worth mentioning that adding U.FL to SMA pigtail changes VSWR.

Cayenne LPP is a popular choice. We use it as well. Custom binary format would be efficient and consume less air time.

It’s an option, but I would not consider it unless really necessary. If you still use 868MHz frequency the same Fair Use Policy applies to your gateway. It’s related with EU law for ISM not TTN itself. And TTN adds redundancy (multiple gateways) and reliability (gateways usually have very good and well placed antennas).

How do you modify your antennas?

I have no equipment to test antenna parameters yet. I think I’ve seen some inexpensive meters (< E100,-) In my experience (without measuring), the “big” antennas worked best. I suppose those just are just quarter wave, without any tricks like integrated inductance in the antenna.

For my node, I think I’ll stick to ADR, to keep things as automatic as possible.