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13

A Raspberry Pi 3 is a pretty serious bit of kit when you think about it Quad core Arm Cortex 1gb of RAM a onboard GPU That is a huge amount of memory, easily more than enough to run a MQTT broker and something like Node-RED to interface between a LoRa radio and the broker. We have a commercial gateway (MultiTech MultiConnect Conduit) in the office which ...


9

These are mainly very general answers that apply to all receiver/transmitters not just the LoRa gateway. As a rule you should not run transmitters with out an antenna attached (or a dummy load) as the transmit energy is effectively reflected by the open socket and can damage the equipment. You may be OK to run the gateway without the expansion card if there ...


8

Yes, using LoRa radios to receive messages is possible. For the Arduino platform, the LMIC library can be used. See my code for mobile node with gps and gateway. The gateway publishes data to a service called PubNub, which has a free tier that probably is sufficient for your needs. It should be fairly easy to modify the gateway code to send data to your own ...


8

It seems that a range of at least 440 km is possible with the LoRa protocol (i.e. there is no time-of-flight assumption as in GSM). The correct way to answer this question is by looking at the link budget for your transmit/receive arrangement. Although the basic calculations are simple, knowing the right way to do the calculation is not so simple. To ...


7

How big is a LoRa packet including PHY headers I assume you mean MAC header? After some LoRa chip has demodulated the LoRa radio signals for you, it will give you the LoRa PHY payload. For a LoRaWAN uplink such PHY payload holds a MAC header, MAC payload and MIC. For 1.0.x the rule of thumb seems to be that a LoRaWAN packet is at least 13 bytes larger than ...


7

First, your question is unanswerable by the way as no one could tell what will work in an unknown environment. For example if there is a huge hill between the two modules, or a big city then it won't work. But if your module is attached to a ballon which has an altitude of 38 km, then you are possibly good. While the balloon was at an altitude of 38.772 ...


7

The data sheet is not too forthcoming on their expectation for connecting an antenna (other than suggesting that a matching network is mandatory if you run high power). However, from the photos in the linked article, it's clear that what was used in this example was a 50 ohm coax to SMA 'pigtail'. You can get a short coax pre-connected to an SMA (with maybe ...


7

Just to clarify from what I undestand when researching these modules: RFM69x - Packet Radio (not LoRa) RFM96x - LoRa Radio (or RFM95 / RFM97 - thanks Chris) If you're trying to use an RF69x for LoRa, that's your issue A quick google search should show you how to get LoRaWan up and running if you have the correct radio module (RFM9xx). Hope this helps. (...


7

Indeed, the whole point of "The Things Network" (TTN) is that multiple LoRa gateways are used to transfer messages between LoRa radio signals and the Internet based routing. And these don't even have to be gateways owned by you - by registering your device on TTN you have access to all gateways in the public system, and by making your gateway part of TTN, ...


6

The SX127x family of chips from Semtech are modems supporting both LoRa and (G)FSK modulations (including ultra-narrow band FSK). Coupled with a microcontroller implementing the relevant stack(s), they are already used for with following IoT network protocols: LoRaWAN, Sigfox, Wireless M-Bus, DASH7 and Symphony Link. They could probably also be used with ...


6

Using the information in this answer: https://iot.stackexchange.com/a/2934/746 At (a worst case) max useable payload of 51bytes it will take 41,120 packets to send a single image (assuming no need for re-transmits). I do not think this will be practical.


5

LMiC does not tell your code when transmission has started, but you could enable debug logging. When you're transmitting well below duty cycle limitations, then LMiC will often send almost immediately. It might postpone things: When using OTAA and the node has not joined yet, it will first try to join when the first packet is scheduled. When duty cycle ...


5

One Access Point for 250m2 and 3 floors, seems to stretch WiFi a bit. It depends on the material in the building, surrounding interference and antenna. To give a answer, one should do a survey and measurements on site. A Guesstimate would be probably not.


5

WSO2 IoT server itself can be used for your purpose without a problem. You don't need to integrate lorawan-server and use WSO2 server as a MQTT broker here. I was able to successfully try out their Raspberry pi sample. There they explain how to use their MQTT broker to establish the connection between the Raspberry pi and the WSO2 IoT server. They do have ...


5

can't I have "something" that receives the data and sends them over ip-based networks? Yes you can and that's called a gateway. https://www.lora-alliance.org/technology https://www.thethingsnetwork.org/docs/gateways/ These services like Things Network and Loriot.io provide software for the gateways, cloud servers (a backend) and API's. You don't need to ...


5

Try a Yagi antenna. Both receiver and transmitter will need an antenna, and they must be aligned with each other (direct line of sight). Just a few degrees of inaccuracy will cause bad reception. There are various DIY yagi antenna guides online, and open source yagi calculator programs that will compute the required dimensions for a 868MHz antenna and balun. ...


4

Formally, you should indeed have a matched antenna when operating a radio transmitter, and antenna matching is indeed frequency dependent. That said, (permissible unlicensed) LoRa RF power levels are relatively low, and the potentially lasting issue with mismatched antennas is from the reflection of transmit power back into the transmitter. The lower the ...


4

It wouldn't be much of a Wide Area Network (WAN) if you just had a single gateway. While you can certainly have nodes report into a single gateway, the more expansive schemes (for example, The Things Network) let multiple gateways coordinate through traditional Internet links, either by all reporting up to a single server or better yet into a network of ...


4

Like stated in answer of your previous question How can I interface a LoraWan network with MQTT? about MQTT and LoraWan, one device can be member in both, but both sides do not have to know about each others. Connect the server that successfully gets the LoraWan data now to Ethernet cable or WiFi and send MQTT to WSO2. It is that LoraWan endpoint server ...


4

A Yagi (and most TV) antennas are VERY directional, they achieve their good range by making sure they direct all energy in one direction. You would only be able to communicate with devices that are on the straight line your antenna is pointing in. This wouldn't really be all that useful. You need to look for a omnidirectional antenna to give the best ...


4

The sx1276-series chips don't support spreading factors outside of SF6-SF12 (per sx1276/77/78/79 datasheet). The new sx1262-series chips support SF5 (per sx1261/2 datasheet). With lower spreading factors at some point it's not spread spectrum anymore and probably best to switch to FSK modulation. Higher spreading factors put more stringent requirements on ...


3

You need to connect your RFM95W to RPI3 via SPI (as it seems to be done) and then, you will need a driver to allow the Linux kernel to communicate with the device over SPI. After that, you will need to adapt your software to communicate with the driver to send data from user space. It seems no one developed a driver for Linux. The closest (not tested by me) ...


3

LoRaWAN localization uses TDOA: Time Difference Of Arrival. Gateways with the precise timing extension are all synchronized via GPS. When a device sends a frame, the very accurate time at which the frame was emitted is unknown, but by recording the exact time each of several gateways receive that frame (compared to GPS time), and knowing the position of ...


3

This interface is perhaps not as well documented as it should be. As it turns out, the actual SPI data and clock pins (SCK, MOSI, and MISO) are not specified in the struct; instead they are assumed to be wired consistent with the hardware SPI engine. The arguments that are specified in the struct are limited to things which are configurable. That includes ...


3

Do they support the version 1.0.x and not the latest 1.1 version? Indeed. Though I'm not sure of the status of the original LMiC library, the Arduino port you're referring to is based on LMiC 1.5 and indeed only supports LoRaWAN 1.0.x. It's not explicitly noted in its README, but looking at the changes you'll see that the last meaningful commit dates back ...


3

Yes, it is possible. A common way to do this is to have a powered node that can receive data over LoRa and transmit it using ethernet or Wi-Fi to a cloud service. That means that whenever your mobile nodes are in range of the collector node, they will transmit their data to it, and it will, in turn, relay it, using internet technology, to a persistent ...


3

Yes it's free. The idea is similar to the original Internet model, if you set up a gateway you allow others to use it as well and in return you can use other peoples gateways, that way the overall coverage grows and everybody benefits. You don't need to buy a gateway from TTN, you can use any number of gateways*, but I think TTN are now asking that you use ...


3

First of all, trying to launch the integration from an SSH session is a bad idea (it is missing environment variables among other things). With the old version of the integration (before 2.0.11), we somehow needed certificates with an associated policy for the things in the AWS IoT core. This bug is fixed in 2.0.11 (which is the current one at the time of ...


3

I think your best bet at these distances is a GSM modem with a SIM card and a data plan with the cheapest available operator. You can connect the GSM modem to whatever device is taking pictures via a SPI or UART or USB and send your pictures by email, SMS, or MMS message, or even upload them directly to a FTP site. This is a cost effective solution that ...


3

I think you missed how slow LoRa is. It is very, very, very, very slow. The slowest data rate (at SF12, BW125) is just 250 bits per second. That's 31 bytes per second. Just the text of this answer would take 50 seconds to send, without counting any overhead. This full page, including contents, styles, scripts, images, etc. is over 3 MB, that would take over ...


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