[HN Gopher] LoRa: Field Testing Antennas
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LoRa: Field Testing Antennas
Author : zdw
Score : 43 points
Date : 2022-12-20 22:42 UTC (1 days ago)
(HTM) web link (www.sparkfun.com)
(TXT) w3m dump (www.sparkfun.com)
| madengr wrote:
| dylan604 wrote:
| For those with a keen sense of hacking adventurism, picking up
| one of these to just drive around with to see what signals are
| available is fun if you're into that kind of thing. Once you find
| a signal that looks interesting, you can then see if you can
| reverse/decode the signal. There's been a few HN posts about
| decoding signals pulled out of the air, and I always find them
| interesting.
| lormayna wrote:
| Why not using a NanoVNA to measure the antenna performances and
| parameters? It's quite cheap (less than $50) and it will provide
| a more objective methodology to test an antenna.
| dbrgn wrote:
| I did that a while ago (with more professional tools though):
|
| https://www.coredump.ch/2017/04/13/lorawan-868mhz-antenna-te...
|
| https://www.coredump.ch/2017/04/30/lorawan-868mhz-antenna-te...
| SamPatt wrote:
| Probably because they had fun doing it?
| kawfey wrote:
| A VNA still doesn't tell you range an antenna gives over
| another (ie gain). For that, a legit antenna test range is
| necessary, or a hike out in the woods works too.
| madengr wrote:
| AriedK wrote:
| I know it says Field Testing, but the results aren't very helpful
| to find what you're looking for. The antenna 'strength' in every
| direction. We built a EUR200 setup that combines a rotating
| platform, a drone power meter (for 868MHz or 915 in US) hooked up
| to a yagi antenna, and a network testing device as a reference.
| At least gives you a decent impression of how well the antenna
| emits its supplied power, without spending >10k on professional
| equipment.
| steve_adams_86 wrote:
| LoRa seems like a super power for hobbyists. I naively tried to
| use WiFi to network some MCUs around my place (in different
| buildings, some close to the mesh but a couple fairly far) and it
| went terribly. I wound up writing a lot of code to keep the
| connections alive, but after some data logging I discovered the
| two furthest boards were offline around 60% of the time. That's
| in range to seem pretty broken to me.
|
| After a bit of research I discovered LoRa and I'm in the process
| of swapping out the WiFi network. While the bandwidth isn't
| great, I really don't need it. So far I've found a couple test
| boards can communicate virtually uninterrupted over the same
| distance that the WiFi boards typically fail. They also consume
| way less energy doing so! The code footprint is smaller, the
| boards will survive on battery power much longer, and expanding
| the network will be way less hassle.
|
| If you need high bandwidth then I guess it's not a viable
| solution, but if you don't it seems incredible to me. I'm still
| in mild disbelief that something so cool and useful is so cheap
| and easy to use.
| womod wrote:
| Antenna type and design can make all the difference in the
| world with regards to performance. Even plain-old 2.4GHz or
| 5GHz WiFi can work great over large distances provided that you
| use a parabolic reflector, yagi, log-periodic, etc. Microwave
| linking is all the rage nowadays, with WISPs popping up all
| over the place and large commercial operators using microwave
| links as backhaul between internet-connected sites (usually
| cell tower sites). But LoRa is still really awesome for low-
| bandwidth data with minimal antenna considerations, and having
| it be such a convenient standalone package with some of the
| boards available is just icing on the cake.
| steve_adams_86 wrote:
| Do you recommend any resources in particular for learning
| more about improving WiFi range and reliability, or should I
| just google some of those terms?
|
| I briefly dug into it but had the sense that it might be a
| bit over my head. I'm not great with hardware -- I just goof
| around with it a bit and make fun stuff for hobbies. Making
| WiFi work better would be really useful for some things,
| though.
| windexh8er wrote:
| LoRaWAN is so awesome. It's the sweet spot between Wifi and
| ZigBee/Z-Wave. Has phenomenal range and networking options.
| I've got a few devices around 1/4 mile from the base station
| and they're highly reliable. I wish the home automation market
| would have adopted it earlier. There are a few brands out there
| that are decent but it's unfortunate the market is so
| fragmented. At least with Z-Wave you're not tied to a specific
| vendor and interop is relatively good these days. LoRa is
| pretty immature in the market but, at least, it seems to be
| progressing.
|
| The downside to LoRaWAN is the implementation of mesh. It,
| generally, requires far more planning currently - but I'll be
| curious to see how it evolves with more mainstream
| applications.
| steve_adams_86 wrote:
| I wondered if LoRa is a little immature still, but I wasn't
| sure. For how easy it is to get going with, it still requires
| quite a bit of playing around, non-standard libraries, etc.
|
| I was totally content to accept that once I saw how well it
| solved my problem. WiFi has a clear cut path to getting what
| you want accomplished which seems great from the outset, but
| is totally useless if it's not reliable. I've found that
| WiFi-based projects generally need to be really, really close
| to an access point to be properly reliable.
|
| As another comment mentioned though there are probably plenty
| of ways I could mitigate these problems, so it's as much an
| issue with me trying to use a technology wrong as it is a
| hard limitation of WiFi.
| PragmaticPulp wrote:
| Fun idea, but why did they travel in different directions for
| each test? The environment and line of sight are everything in
| this type of testing, so it doesn't make sense to wander in
| different random directions and then try to compare numbers.
|
| For the final test they went up in elevation and had what appears
| to be line of sight back to the base station. That alone was
| probably more impactful than any antenna change.
| dylan604 wrote:
| Just a guess, but if you know about how far your anticipating
| getting a signal, you can draw a circle on the map and pick the
| direction that will give you the best chances. They clearly
| state that line of sight is suggested. At one distance, there
| might be obstructions along the same line as a previous test.
|
| They could also just be bored with the first path and looking
| for something different.
|
| >For the final test they went up in elevation and had what
| appears to be line of sight back to the base station. That
| alone was probably more impactful than any antenna change.
|
| For the final test, they were 6.4 miles away. If you think the
| elevation was the only thing that helped, you're just being
| obtuse. Is it deliberate? I'm asking for my friend Andy
| Dufresne
| fest wrote:
| Field comparisons of antennas is tricky to do correctly- you
| really want to use the same location, ideally far away from human
| settlements (who knows how much background noise was there on a
| particular test day) and ideally under the same weather
| conditions.
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