[Link] LimeSDR Mini Crowdfunding: $99 Early Bird RX/TX, 12-Bit, 10 MHz - 3.5 GHz SDR

hardware
electronics

#1

This is by all means the best price/quality SDR for beginners at the moment. If you always wanted to get started with SDR now is the best time to do it.

UPD: If you never heard of Software Defined Radio I would recommend to watch Software Defined Radio with HackRF course by Michael Ossmann. I find episodes 8 and 11 particularly interesting since in these episodes the concrete examples of using SDR are given.


(oaktree) #2

Mind explaining what an SDR is?
edit: Software Defined Radio if anyone was wondering.


(Not a N00b, but still learning) #3

So, am I right that one can not only receive, but also send with it and like run OsmocomBB on it? :blush:


#4

Right, you can send a receive (simultaneously) anything on frequencies from 10 MHz to 3.5 GHz. Also you can extend this range by using additional devices called upconverter and downconverter.


#5

@oaktree, thanks for your feedback!

Good point. I forgot that most people never heard of SDR. I added a link to the corresponding article on Wikipedia and also a link to Michael Ossmann’s course.


(Matrix2600) #6

I think a more detailed post could help a lot because I’m confused a bit about a SDR and its uses. Just a suggestion.

Other than that, interesting share.

~Cheers!


(3,4,5-trimethoxyphenethylamine) #7

I’m still waiting for my full-sized LimeSDR board to ship. It’s scheduled for September 30. The LimeSDR Mini looks really cool. The main problem is that the FPGA only has 16k PLG. Also, one of the problems is that it only has one set of matching networks and I don’t think It’s great if you want to get started. For the price the only competitor is the ADALM-PLUTO which is worst. If anyone needs help buying antennas for the board just let me know.

ps: I don’t recommend ordering the LimeSDR mini right now, wait until we get some input about the matching networks’ range. The board claims to have a 10MHz to 3.5GHz frequency range but the usable range will be much shorter depending on the matching network specifications. If your goal is mainly cellular communication (GSM, LTE, etc.), I wouldn’t worry a lot, that is the main focus on the project and the matching network will certainly cover those frequencies, but for other applications, please wait. I’ve already contacted the team and I’m just waiting for a reply.


(3,4,5-trimethoxyphenethylamine) #8

Usually Radio applications are achieved by an real circuit inside the device. For example, the radio you have in your car. It has a circuit which will do FM demodulation. The analog radio signal will be supplied in the input and then the circuit will convert it to data, in this case audio. The difference between Hardware Defined Radio and Software Defined Radio is that, the SDR device will send the raw analog signal to the computer. With the analog signal, the computer can then process the signal and transform it into data. This works just like a soundcard, but for radio waves. Let’s use other example. Imagine you want to add some kind of effect to your voice. You could use a device specifically for that, like those Darth Vader voice changers. You could also use a microphone to record your voice to the computer and then use a software to modify your voice. The problem with the physical device is that it wouldn’t let you do any kind of modification other than what it was designed for, with the computer you could. This is what SDR devices do, but for radio waves. So the reason why SDR is so interesting is that you can do anything with it, software is free and easily modified while hardware is not. If I wanted to make an AM demodulator, I would have two options. I could design and manufacture a circuit or I could simply create a program (with SDR). What do you think it’s easier? The only problem raised by this kind of implementation is the performance. While using a circuit, the analog data would be directly modified. But using a SDR device, the analog data would be converted to digital and then modified.


(3,4,5-trimethoxyphenethylamine) #9

Okay, we just got an update about the matching networks present in the device. There will be 2 sets of networks (two for Tx and two for Rx). They should match High and Low bands. I’m more optimistic about this but I still recommend to wait until we get information about the actual performance. In the original LimeSDR, we had 3 matching networks for each Rx channel and they still managed to left out the HF band. Link of the update below.


(Austin) #10

I am getting one of these in work so I should be able to test anything you would want to know after it arrives.


(3,4,5-trimethoxyphenethylamine) #11

Thanks but andrewback I’ll test once they receive one of the final version boards. We should get the graph of the performance across the spectrum before the boards start to be shipped. But what do you do for work?


(Austin) #12

I am a lab assistant for a wireless system research group at my university. I’ve mainly been working on setting up and optimizing a LTE network lately.


(3,4,5-trimethoxyphenethylamine) #13

Oh, that’s interesting. Have you had any success? I’m going to university next year.


(Austin) #14

Yeah I’ve got a fully working 5G LTE base station running. I’ve just been trying to optimize it and make it a viable testbed for network experiments.


(3,4,5-trimethoxyphenethylamine) #15

Cool! What’s your current setup (hardware/software)?
When my LimeSDR ships (8~10 days) I will use OpenAirInterface to attempt this.


(Austin) #16

Hardware:

  • Dell optiplex x2
  • usrp b210
  • moto g5 plus

Software:

  • OpenAirInterface EPC
  • SRSeNB
  • Ubuntu 16.04 running 4.10 - low latency kernel

So the optiplex’s are my EPC and eNB machines and the moto is my test UE. Right now the EPC and eNB are connected by a straight ethernet connection, but because of the nature of the project the lab is working on right now it’ll be moving a wireless ad-hoc network. If you end up setting up this network and have questions I’d be more than happy to help you out or the mail-list is a great area to ask questions.


(3,4,5-trimethoxyphenethylamine) #17

Hum, that’s not very different from what I’ll be running. Do you have discord or other similar app from communication? If you have discord, you can add me FFY00#1854.