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Topic: LoRa mesh network (Read 794 times) previous topic - next topic

royholz

Has anybody had experience with creating a mesh network!!

Can you please advise if I am on the right track before I purchase. I need to monitor some rural sites (eg water tank levels) and would like to access this monitoring back at home/office to create a web based monitoring system.

The sites are at varying distances up to 5.7kms and not all line of site. I believe that if I create mesh network it will overcome the line of site issue.

If I were to use the RFM95 LoRa 915Mhz (Australia) breakout with an Arduino UNO at each site will I be able to create a mesh network and in turn connect to the internet.

Will code for this be a nightmare or are there some appropriate tutorials out there already

Thankyou
Roy

jremington

#1
Dec 06, 2017, 05:05 pm Last Edit: Dec 06, 2017, 11:12 pm by jremington
Great project! There are several open source mesh network projects, including an Arduino/ESP8266 example.

Pick a couple, look through them and decide if it looks worthwhile to adapt them to the chosen device. This example looks promising, but a high priority would be to replace the crash-causing String processing code with reliable C-string character arrays and functions.

But first, get a single transmitter/receiver pair working to your satisfaction.

lastchancename

Just curious...
Is 915 the correct frequency to use in Australia?
I would have expected 433. I haven't used LoRa yet.
Cheers.
When posting - use the toolbar and read the stickies if you're not sure!
http://forum.arduino.cc/index.php?action=dlattach;topic=528443.0;attach=244985

horace

915MHz appears to be the correct frequency
https://www.thethingsnetwork.org/country/australia/

If there are Lora gateways in the area you can transmit data directly to The Things network (note the data limits per day) and then using HTTP integration POST to a database
If there are no local Gateways siting one at a central point in the area could work (Lora range depends on local conditions sich as tress, buildings, etc)
An alternative could be to build a mesh of Lora peer to peer devices and use a GSM modem to transmit data to your database
You probably need to experiment

bluejets

Although Instructables may seem dodgy at times, this one seems ok.

http://www.instructables.com/id/Simple-Arduino-Wireless-Mesh/


jremington


horace

the APC220 devices could be an alternative to using LoRa32u4 RFM95 modules to build a mesh - cost seems to be similar - Lora is claimed to have greater range
Once you have the mesh built how will you transmit the data to your database? 
I suggest some onsite experiments

srnet

A Pro Mini is quite happy to drive a $4 LoRa module.

APC220s are $40 and LoRa32u4 RFM95s $35.


For remote sensors and the like its usually a good idea to use a bare bones ATMega328 setup, that way you can be sure to get the sleep current down to a handful of uA.


$50SAT is now Silent (but probably still running)
http://www.50dollarsat.info/
http://www.loratracker.uk/

bluejets

As seen in reply #1.
Sorry about that....missed the "this example" bit.

royholz

thanks for your help everyone

mahomsolom

Despite that I am new in arduino projects I know you can build mesh networks using XBEE chips. There is even a Xbee mesh kit sold in my country.
Is there a reason that nobody suggested this? Am I missing something about this technology??

mahomsolom

Sorry bout that, I missed the LORA part..

horace

the XBee-PRO® 900HP claims a range of up to 28 miles (but could be expensive?)
https://www.digi.com/products/xbee-rf-solutions/sub-1-ghz-modules/xbee-pro-900hp
I have used the indoor XBee Pro modules but never the 900HP

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