Single Channel Packet Forwarder part 3 [Deprecated]

Ryanteck thank you so much for your clear explanation.
The SCG implementation is only for demonstration of a simple protocol implementation.

I’m transmitting at 868MHz actually because is the allowed frequency by the fabricant library (Semtech), with a 500Khz bandwidth, using SF7 and coding rate 4/5.

I’m trying to find the way to transmit at least a char sequence because the coded result is not usefull at all for me (I did it with two end devices, and I want one of them to become a gateway with a RPI).

For what you said to me the key is on the end device, so I’ll keep working on that.

Thank you, again.

If you’re sending text (don’t) then your packet should be about 17 bytes: 13 bytes LoRaWAN overhead, plus 4 characters. What you’re showing are a whopping 126 and 40 bytes. So chances are those are not your node’s packets.

(Too bad you posted a screenshot of the terminal output, which does not allow us to copy the payload for further investigation/help. Please post text next time.)

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Just something I noticed, Not sure if its a single channel gateway hardware or software issue.

I seem to be picking up something every hour with random Dev addrs. (the ones ending in 2C are correct and also picked up by my multi channel gateway.


You’re assuming those are DevAddr’s. But it might not even be LoRaWAN. You need to know the secrets to validate the MIC, to be sure it’s a valid LoRaWAN packet. You might be looking at plain LoRa, unrelated to LoRaWAN.

arjanvanb thank you for your time.
It’s true about the 17 bytes size, but the node is actually sending a 32 bytes payload (for text) plus LoRa data.
Sorry for the terminal screen, here goes the text (from a similar situation):

SX1276 detected, starting.
Gateway ID: b8:27:eb:ff:ff:33:87:ea
Listening at SF7 on 868.100000 Mhz.
stat update: {"stat":{"time":"2018-03-07 15:07:08 GMT","lati":0.00000,"long":0.00000,"alti":0,"rxnb":0,"rxok":0,"rxfw":0,"ackr":0.0,"dwnb":0,"txnb":0,"pfrm":"Single Channel Gateway","mail":"","desc":""}}
stat update: {"stat":{"time":"2018-03-07 15:07:38 GMT","lati":0.00000,"long":0.00000,"alti":0,"rxnb":0,"rxok":0,"rxfw":0,"ackr":0.0,"dwnb":0,"txnb":0,"pfrm":"Single Channel Gateway","mail":"","desc":""}}

…(continues for some minutes)…

Packet RSSI: -109, RSSI: -111, SNR: -11, Length: 70
rxpk update: {"rxpk":[{"tmst":1291520413,"chan":0,"rfch":0,"freq":868.100000,"stat":1,"modu":"LORA","datr":"SF7BW125","codr":"4/5","lsnr":-11,"rssi":-109,"size":70,"data":"1F/EY3ii6AgSJVdbmfM8CBfpAjio+BDz9/ZSHYnF7kZj8JRm0a3upLCLhDRnPx2MMI809OVW48YfpDnpCzXURpqkV1vUFA=="}]}

…(and again continues for some minutes with:)…

stat update: {"stat":{"time":"2018-03-07 15:35:08 GMT","lati":0.00000,"long":0.00000,"alti":0,"rxnb":1,"rxok":1,"rxfw":0,"ackr":0.0,"dwnb":0,"txnb":0,"pfrm":"Single Channel Gateway","mail":"","desc":""}}

That’s plain abuse in EU. But even then: 32 bytes plus, at least, 13 bytes overhead does not explain either the 126 nor the 40 bytes you’re seeing once “every 15 minutes or more”. (Nor the 70 bytes you’re showing in your last post.)

In hexadecimal, that starts with 0xD4 so does not seem to be a valid LoRaWAN packet.

(As an aside, see How do I format my forum post?)

I need to make a low coast LoRa Gateway using Raspberry pi 3 and Wifi LoRa 32.
It is possible to do it ?? then witch implementation should i use for this ?

start using search … there are many topics about building gateways.

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Thank you.
Yes i found some, but the problem is that they don’t use the same LoRa module, differents pins and others specifications. So i guess that will not work ! what do you think ?

why do you need a RPI 3 to build single channel gateway if you have a heltec board ?

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If by ‘Wifi LoRa 32’ you mean one of the ESP32 boards fitted with a LoRa device then I dont thing you can use it with a Pi.

As @BoRRoZ suggests, the Wifi LoRa 32 boards are standalone they have their own processor, no need for a Pi anyway.

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Thank you guys,

First, i mean by a ‘wifi lora 32’ a “Heltec WiFi LoRa 32 – ESP32 with OLED and SX1278”.

Then, actually i connect the board to a DHT11 sensor, to collect Temperature and humidity. Its work and the Data are displayed on the OLED Display. Now, I want to do something with these data, something like : store it in a database or use it on a web application … for example.

I also read that a LoRa network needs three things : end-devices (for me its a board with the sensor) , a LoRa Gateway and a LoRa network Server. So this why i am asking for a Gateway !

Could please suggest me something to do with the data i collect, and give me some explanation why i don’t need a gateway ?

sure… LEARN don’t expect us to do your ‘home work’
start reading and use search here on the forum and google to understand the basics of the things network.

Thank you for help.

But you did ask;

“I need to make a low coast LoRa Gateway using Raspberry pi 3 and Wifi LoRa 32”, hence the answers you got and you do not need a node (Wifi LoRa 32) to make a Gateway.

Try a Google search on;

raspberry pi lora gateway

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Hi all,
does anyone know a working library for a Singol Channel Gateway (Raspberry PI3),
with the possibility of downstream messages?

I am currently using /tftelkamp/single_chan_pkt_fwd , but it does not have this feature.

In the summary at the beginning of this tread, for the gateways made with ESP8266 are indicated a couple of packages that have this possibility, but I have not found anything for raspberry PI3


Hi all
I found and verified the operation of a library to create a gateway with Raspberry PI3 and Dragino Hat v1.4, which allows the downstream messages

I used the code
following the directions with the changes written in the post1
DRAGINO problems and solutions topic
and in the post2
DRAGINO problems and solutions topic

@BoRRoZ do you suggest making a dedicated topic ?


sure… if you make a clear topic start with all the info :roll_eyes:

I published all the info collected in a new topic LINK, I hope I was clear :grin:

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yes thank you ! great write up very helpfull :sunglasses: