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LimeSDR

limemicro.com

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Re: LimeSDR

#91

Post by syedkarim »

touisteur wrote: post #61
syedkarim wrote: post #33

Earlier quoted context omitted.

We are shooting for a price of $299 for KrakenSDR.

Oh thanks for your answer, that's very interesting! For someone wanting to upgrade from rtl-sdr that seems a good step up. While you're here, I'm particularly interested whether you're aiming for something more ambitious some day or 100% focused on kraken? I'm thinking coherent 32/64 rx channels or more? Also, is there a way to assemble two krakens and synchronize them somehow so as to have 10x coherent rx? :-) There…

We have plans to offer a few different versions of KrakenSDR. The entry level version will likely be the current version with 5 tuners. We are laying out an idea for 8 tuners, integrated CPU, and pre-set antennas; basically a turnkey system for remote operations. We can definitely produce more exotic beasts, but I don't think there is much of a market for a Kraken with a hundred heads.

Re: LimeSDR

#92

Post by ohazi »

azinman2 wrote: post #90
ohazi wrote: post #71

I wish them luck, but judging by the ~week I spent trying to get a LimeSDR mini to work, their product is so half baked that it's basically not fit for purpose, and if you're considering getting one, I'd recommend something with an Analog Devices front-end instead. The PLL would fail to lock at random frequencies and temperatures. You'd try to scroll through e.g. the 2.4 GHz ISM band and would randomly get downconver…

Which USRP do you use? And what do you do specifically with it?

A B205.

Mostly playing around with high spectral efficiency digital modulation techniques like PSK/QAM and OFDM using GNU Radio. Trying to shovel as much data as I can between two links with as little power as possible. I'd like to experiment with below-the-noise-floor communication, but haven't gotten there yet.

It's sort of silly, because you can do all of this in simulation, but it's more fun with real hardware. Eventually I'd like to be able to build a (solar?) drone with a radio system resembling a cell tower and do ground-drone-ground relay experiments, but I'm extremely not there yet.

I also wanted something that could transmit after I got a ham radio license (out of boredom during the pandemic, shortly after they started doing testing online), but haven't really used it that much, as I don't really have a good antenna set up. For data experiments, a wire or a PCB trace works well enough.

I also do a lot of embedded Wi-Fi / Bluetooth stuff at work and would like to use this for packet captures, but haven't needed to yet. It's completely overkill for something like that though.

Re: LimeSDR

#93

Post by 7kay »

stefan_ wrote: post #29
octopoc wrote: post #16

Earlier quoted context omitted.

I mean if you used an SDR in your consumer product. Let's say you make a dual purpose LoRa / WiFi radio to put in vehicles for a fleet management solution. If you use an SDR, you'd have to lock it down with DRM to prevent end users from repurposing it.

Yes, but the same applies to your WiFi router even if it has hardware filters. Its simply a certification requirement. That doesn't have anything to do with LimeSDR. This is already not a product that is certified for anything. It exists in a very gray zone where anyone using it for transmission is likely in violation of the law unless they obtained a development/testing license in the specific band they are using.

The easiest way to leave the gray zone would be to get a ham radio license. Although this might vary from country to country, generally you are allowed to use selfbuilt transmitters in specific frequency ranges, which also includes noncertified hardware.

Re: LimeSDR

#94

Post by vdqtp3 »

stefan_ wrote: post #29
octopoc wrote: post #16

Earlier quoted context omitted.

I mean if you used an SDR in your consumer product. Let's say you make a dual purpose LoRa / WiFi radio to put in vehicles for a fleet management solution. If you use an SDR, you'd have to lock it down with DRM to prevent end users from repurposing it.

Yes, but the same applies to your WiFi router even if it has hardware filters. Its simply a certification requirement. That doesn't have anything to do with LimeSDR. This is already not a product that is certified for anything. It exists in a very gray zone where anyone using it for transmission is likely in violation of the law unless they obtained a development/testing license in the specific band they are using.

> likely in violation of the law...development/testing license

Or they just have a ham radio license

Re: LimeSDR

#95

Post by themulticaster »

ngz00 wrote: post #88

Any suggestions on where to start to use this as a LTE uplink that reads from an SD card and uploads images? I'd like to replace my expensive faulty game camera subscription.

In addition to what myself248 said:

In case you aren't familiar with the details of consumer RF standards (including IEEE 802.11, but especially LTE or anything cellular related) or don't have some prior RF knowledge: To put it mildly, LTE is not an easy standard to implement on an SDR, especially if it's your contact with SDRs. Even GSM is nowhere near a simple stack.

If you want to get a feeling for what kind of cellular projects are possible using SDRs from a hobbyist/free software perspective, have a look at the Osmocom (Open Source Mobile Communications) projects [1] as well as Harald Welte's blog [2] (one of the main Osmocom contributors). The Osmocom projects are focused on the carrier side of LTE/GSM networks AFAIK.

Another warning: While cellular technology involves lots of networks, it is completely different from the standards and terminology used in the Internet. For example, citing the description for OsmoHNBGW: "An Open Source implementation of a HNB-GW (HomeNodeB-Gateway), implementing the Iuh, IuCS and IuPS interfaces. It aggregates the Iuh links from femtocells (hNodeBs) and presents them as regular IuCS and IuPS towards MSC and SGSN (such as OsmoMSC and OsmoSGSN). It uses M3UA as signaling transport." The description totally makes sense to an insider, but if you only dabbled with TCP/IP, routers and switches so far, be prepared for learning a whole new world of networking terms.

If you are familiar with RF/cellular engineering and/or if you're trying to do this on a corporate budget then you probably already know what I mentioned above, and your project can certainly be realized for $$$.

If you're looking for a one-off DIY solution then you could use something like a u-blox SARA-R4 [3] modem (for NB-IoT/low bandwidth). Similar boards with higher bandwidth also exist.

[1] https://osmocom.org/projects

[2] https://laforge.gnumonks.org/blog/

[3] https://www.sparkfun.com/products/14997

Re: LimeSDR

#96

Post by slobiwan »

jjwiseman wrote: post #62
CSSer wrote: post #38

Earlier quoted context omitted.

This sounds really cool. When you say 'around you', what kind of radius are we talking?

As others have said, it depends on terrain, your antenna, the altitude of the aircraft, etc. But generally, 50-60 miles is pretty easy with almost any setup. I have an ADS-B antenna mounted on my roof that feeds into a filter and an amp, and I get less than 50 miles in some directions (because of mountains) and more than 150 miles in other directions (over the ocean). Here's a map of my coverage (any altitude), with…

How do you get that footprint plot? I'm using dump1090-fa and don't see it

Re: LimeSDR

#97

Post by user-the-name »

Blackthorn wrote: post #11
jquast wrote: post #8

Earlier quoted context omitted.

Ham It Plus can go upconvert as low as 300Hz, compatible with any SDR you just shift the frequency in software https://support.nooelec.com/hc/en-us/articles/360005812474

Guess I didn't make it clear and that's my bad. I need to output 5khz, not input. The input is a more modern Bluetooth protocol.

Why not just use audio out then?

Re: LimeSDR

#99

Post by mNovak »

ohazi wrote: post #92
azinman2 wrote: post #90

Earlier quoted context omitted.

Which USRP do you use? And what do you do specifically with it?

A B205. Mostly playing around with high spectral efficiency digital modulation techniques like PSK/QAM and OFDM using GNU Radio. Trying to shovel as much data as I can between two links with as little power as possible. I'd like to experiment with below-the-noise-floor communication, but haven't gotten there yet. It's sort of silly, because you can do all of this in simulation, but it's more fun with real hardware. E…

Wait, they're doing the exams online now? My laziness to go to a testing center has been holding me back this whole time

Re: LimeSDR

#100

Post by jpm_sd »

ohazi wrote: post #71

I wish them luck, but judging by the ~week I spent trying to get a LimeSDR mini to work, their product is so half baked that it's basically not fit for purpose, and if you're considering getting one, I'd recommend something with an Analog Devices front-end instead. The PLL would fail to lock at random frequencies and temperatures. You'd try to scroll through e.g. the 2.4 GHz ISM band and would randomly get downconver…

Yep, the USRP series is solid. National Instruments buying them was really smart.
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