New asset tracking project

Hello TTN community,

I am pretty new to this stuff but totally excited for this one.

Was browsing the internet looking for GSM alternatives to GPS trackers and that’s when I came across LoRa. I am trying to build a project consisting in tracking assets like laptops so the end product would have to be quite small to fit inside one. Also would need to keep the price relatively down to justify the project (some laptops are gen 5-6 and not quite worth spending £100+ to track them).

I am thinking of tapping into the laptop rails (to charge the battery which would be a small one) to power up the device.

To point out the requirements, I am considering the following ;
1.GPS signal to be transmitted weekly
2.Manage the tracker so I can lower the transmit time in case of theft or loss
3.Battery life should be okish as it wont be transmitting daily
4.Size relatively small to fit inside the hdd bay area(or somewhere else)
5.Wifi is optional**

I can use the in built wi-fi of the device and connect it to the laptop hotspot that would be forced in azure policy and that would be used daily until theft or loss and that where LoRa comes in.

I am open to any suggestion and am gaining knowledge daily by looking at projects and stuff but as I am quite a beginner to TTN could really appreciate a little direction.

Many thanks and can’t wait to be an active part of this wonderful community.

There are some gateways in London and I assume they are accessible to the public(that’s what I’ve come to understand from google xD)
Would the tracking device be able to upload the location to the satellites passing above UK and therefore to the TTN ?


What is the problem you are trying to solve - I’d guess at college assets vs students?

Read / watch this: - the Fundamentals section are absolutely core to making any progress - the rest is good to know as well. This is the tip of the iceberg, plenty more info once you get started.

Not really, you may have misunderstood how it works - GNSS satellites send out signals, are picked up by the GNSS receiver, you package it up & send it out by LoRaWAN to be picked up by a terrestrial gateway. Uploads TO a satellite are a bit more complicated ie expensive. But yes, any gateway on TTN will be able to pass the message on to your application.

This means the asset won’t know where it is inside a chunky building as it won’t hear the various GNSS constellations and it will need to be in range of a LoRaWAN gateway, which in urban areas can be 100’s of metres, 2km on a good day, depending on where both ends are and the size & quantity of intervening buildings. That’s not to say don’t prototype, I’m just setting expectations.

GNSS = generic, GPS is the US implementation, which was the first but now there is the Chinese, Russian & European satellites too.

Well, fundamental to ‘tracking’ laptops,especially if they are indoors, is that you can get their location from GPS, and that is very difficult in the circumstances you suggest.

GPSs dont work well indoors, the GPS signals are very weak, and for something real small going inside a laptop, which implies a small and less effective GPS antenna, you might not get a location fix from GPS at all, so no good for tracking.

Mobile phones and the like can often get GPS fixes indoors, but they use a system called GPS assist which uses the mobile connection to download satellite info directly to help the phone get a location fix in less than ideal locations.

But this is all theory.

Ignore the TTN\LoRaWAN stuff for now, what you need to do is test some small GPS setups (with small antennas) and see if you can get location fixes indoors at all.

I have tried with small ceramic GPS antennas and it works quite well. It takes a while to fix the position but it does work. My issue is mostly with LoRa. I have watched tons of videos suggesting that it might work but on heavy dense urban areas it would have bad coverage. I’ve seen that the gateways are expanding in London and I am deciding where to put the one I will build.

Using GSM is quite expensive and not worth it on cheap laptops and atm have not found anything worth in the UK.

I was asking about the LoRaWAN. Do LoRa satellites pick up signal from nodes or only gateways do that?

You misquoted LoRaTracker - that was my comment. Which LoRa satellites are you thinking of?

On tinygs website there are fossa satellites and others that do pick up signal from ground stations. MY question might be rather stupid but as gps module communicate with satellites is it possible for nodes as well to transmit signal to satellites ?

Fair enough, you can read the results of some tests on GPS antennas here;

Not sure those tiny ceramic antennas are reliable enough or good enough for a commercial product.

You mean to satellites in low Earth orbit ?

I think there are now a couple of Amateur radio satellites using LoRa in orbit, but they would only be in range for maybe 2 lots of 10 minutes a day. Those satellites cannot be used for commercial purposes.

And GPS modules only receive signals from the GPS satellites in orbit. The GPS satellites need large amounts of transmit power for the signals to be received on Earth.

Lacuna Space were setting up a global LoRaWAN;

Cannot seem to find their Website, so not sure how they are getting on.

Yeah I’ve read about them. As I said in the first post I do not need a real time tracker. As long as the laptop is still in use within the company, I can force the mobile hotspot to be on by azure policy. As long as he is using the laptop, wont have any use for LoRa. LoRa comes in after possible theft/loss or if the laptop goes out the geofence. Even than wouldn’t need a real time signal. This is more of an hobby project as we started ordering laptops with GPS imbedded and could end up with other uses after I get some experience with IOT. Though I still have 200+ left that need to be tracked.

For this will be using esp8266 with a gps antenna. Could even use wi-fi positioning.

What antenna/dbi would be needed to get the best signal ? I am experienced with microsoldering and general electronics, but technology varies. That said I can modify the laptop to accommodate the antenna if need be.

The max dBi of the antenna will determined by the transmit power used and the legal restrictions.

TTN nodes are normally 14dBm, which is the maxiumum power permitted through a 2.1dBi antenna.

So that means a 25mW power output. What module would you suggest for trials? WIll start building and programing both node and gateway so tests can start.

Lacuna are normally to be found at but their certificate has gone awol and I’ve been trying to reach them for weeks - if anyone knows where @RobSpurrett or @telkamp are that would be good.

Please can you build a simple device using the extensive resources & information that is on the forum and in the docs so that you have some background to your enthusiasm. LoRaWAN has many moving parts, so start out with a pre-built gateway like a TTIG so your DIY device has something to hear it - otherwise you end up debugging both ends which is almost impossible. Then you can build a gateway. Then you can start doing power consumption measurements and range tests. Then you can add a GPS to the device (having already tried the GPS standalone inside the laptop). Do too much at once and you’ll not be able to figure out what isn’t co-operating.

And if you actually tell us your use case, like college asset tracking, as requested above, more useful information could be given - like which radio set to use that is really really good an indoor tracking.

This are laptops given to employees on different construction sites or WFH. Over the last couple of year some have been stolen/lost so we need to keep track of them. The newer 12th gen we are buying do have integrated GPS provided by the supplier so no need for them. But we have 200+ left that are 11th gen and below. Cost wise is not worth to buy a subscription that cost 100£ per device yearly plus the tracker cost. As they approach EOL they would be recycled and newer ones ordered. Then we could move the trackers to other assets that we might need tracking.

I was thinking of setting up a geofence so if the laptop leaves the site(it should be open air) I can track it for a moment at least. As I said above LoRa will be used after the geofence triggers (until then wi-fi module with provide the link to transmit gps data).

So having said this I would need LoRa + GPS + Wi-fi in the module. Battery with be connected directly to the laptop rail and maybe a backup 100mah? battery.

Also could I use a signal amplifier on site to help with GPS/LoRa signal strength ?

Hi Nick, something went wrong with the certificate, but it’s being fixed. We’re still reachable by e-mail. See you at TTC next week?

You can get GPS repeaters, but they will only re-transmit the co-ordinates of the repeater.

Not a lot you can do about TTN signal strength, apart from have a Gateway on or very close to each site.

I could use a gateway on each site as I could reuse them on new sites. There are many gateways in London so I guess can use them as well and add more of mine. Any board to start building a node ?

ROI doesn’t look good here - even if 10% are stolen a year, that’s 20 this year and 18 next, for laptops with a value ~£200 that’s about £8k’s worth - so you need to keep the entire project, hardware for laptops, gateways and your time under that - which as you are demonstrably new to LoRaWAN / GNSS etc, will probably be a goodly chunk of time, at which point it will be close to time to buy replacement laptops. You also have to consider that a short run of 200 custom devices isn’t going to be inexpensive either.

And once they are out of range of a gateway, it’s game over - so having them onsite with the WiFi is a bit pointless and until London has universal TTN coverage, they could easily moved somewhere where they can’t phone home.

Search the forum for discussions on using LoRaWAN for tracking (for board recommendations as well), you’ll see there are good use cases but most of the ones that get discussed won’t work if you assume you can leverage lots community gateways.

So I’d sell the laptops you have whilst they have some reasonable value and replace them with the newer model.


Plus in addition, if the hardware is going inside a Laptop, it sounds like custom hardware, so there would be the considerable costs associated with certification too …

Whilst them in power in the UK promised a bonfire of the regulations following Brexit, I dont see the replacement for CE marking, UKCA, being any different.

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How much you reckon is going to cost per device. Plenty of time to spare so no issues on that part. And about me being new to this technology I can catch up pretty fast to the basics needed to build trackers/gateways.

I thought about getting cheap trackers for china with SIM slot but am waiting for a reply from EE for bulk sim and low prices since they will be using barely any data.

Also I want to go forward with the project, at least 10 devices for testing and from there we can decide if still going forward with it.

Was looking into the forum for devices and still not sure which one to buy xD Could use a little direction there for the LoRa nodes as for the GPS already have the small modules.

Many thanks for all the input so far