LimeSDR CrowdFunding Closing in Four Days: 80% Funded
The LimeSDR is a new transmit capable software defined radio with a 100 kHz – 3.8 GHz frequency range, 12-bit ADC and 61.44 MHz bandwidth which is currently seeking crowdfunding. At the time of this post there is about four days left to reach the $500k goal, and it is only 80% funded. To try and reach their funding goal they have released another batch of discounted units which cost only $249 USD. After the crowd funding campaign the price will rise to $289/$299 USD. If the LimeSDR is not funded in time, they write that the project will unfortunately be put on hold and it’s future may be uncertain. We believe that this product is shaping up to be a very good TX/RX capable SDR, like the HackRF and bladeRF, but much better overall and for the same or even lower price.
Recently they also released some new updates that show off some LimeSDR features. In a post previously featured on our blog beta tester Alexandru showed how he was able to get the LimeSDR to transmit DVB-S2 HDTV. In later updates they showed how the LimeSDR can be used to:
- Reverse engineer and then control an off the shelf RF mains switch. They then combined it with a Bluetooth LE wireless temperature sensor and used Pothos to create a program that automatically turns the mains switch on or off depending on temperature.
- Control LoRa based IoT devices. In this post they used the LimeSDR to demonstrate how it can be used to transmit to, receive and simulate IoT devices running the popular LoRa wireless protocol
- Create a 10 MHz LTE cellular site. In this post they also show a mobile phone connecting to the cell site and using LTE mobile internet at 20MSPS.
- Create a spectrum analyzer, oscilloscope and signal generator in GNU Octave. Here they show how the LimeSDR can be used as an “all-in-one” lab tool replacement for several expensive devices.
- Create a Vector Network Analyzer. With the help of a directional coupler the LimeSDR can also be turned into a Vector Network Analyzer to measure parameters such as gain, insertion loss, return loss and VSWR.
- Build a remote radio head. By mounting the LimeSDR near the antenna and streaming the data back over an IP link, coax feed losses can be eliminated.
Nicely priced in the campaign and they hit the target goal.
I’m mulling this. Slightly annoyed that it is just slightly (like a couple mm) too big to fit in an Altoid tin. Seems like MakerNerd 101 — make sure it fits in a candy case. =)
You can have nice aluminum cases with exact dimensions for LimeSDR for $7 – $10 (worldwide free shipping included). From AliExpress of course 😉 See this thread:
https://discourse.myriadrf.org/t/hammond-1455-v2-aluminum-case-for-limesdr/379/8
How do we publicize this project in the last few days to push it over the crowdfunding threshold?
I really want it to succeed, and maybe there are some other outlets this news can be posted on to get a last surge.
Does anyone have any ideas?
Some do provide SWR plots, but I’ve found they don’t match up when I test them. I’ve purchased quite a few antennas from China and suggest you buy from more reputable suppliers that take the time to vet products. The Chinese antennas usually do have decent SWR at some frequency, but rarely the advertised/intended frequency band. I’ve had better results with antennas sourced via Digikey and Mouser. The best antennas I have are the ones I’ve made though. Make them, test, and adjust.
This was intended to be a reply to the discussion about antennas below… Not sure why the reply posted to the top level instead
I can’t get on this bandwaggon. It seems way too expensive to me. IMO, for a decent out of box experience you need to add the shielded enclosure and the four rubber duck antennas. That pushes the cost up from an already pricey $249 to a whopping $599! There is mention of some sort of software that comes with the $599 version, but if you can’t just download the same software for all versions, then the situation is even worse. The $199 “Early Bird” should be (at most) the baseline for the board alone. One more thing that irks me: There seems to be no way to externally discipline the clock. The Rakon oscillator family chosen for this board is a decent, but I can’t easily find out if they used a TCXO OR VCTCXO version part.
It really is not too expensive, in fact it is really really cheap. Nuand bladeRF (closest competition) has much worse parameters and costs much more (at least $420). HackRF One is not even comparable (only half-duplex, 8-bit, 20 MSPS vs. dual 2×2 MIMO full-duplex, 12-bit, 60 MSPS) and still costs $300. LimeSDR for $249 is truly excellent price.
You don’t have to buy expensive case and antennas from LimeSDR project, 10 U.FL to SMA patch cables costs less than $10 from China. 4 GSM / 3G / LTE antennas (similar to those provided by LimeSDR) costs also less than $10 from China. Case can be made DIY from acrylic glass for nearly nothing. So final price for LimeSDR + U.FL patch cables + antennas + case could very well be under $270 (plus shipping for LimeSDR, international shipping for parts from China is free).
Too expensive? With the tunable range it has, FPGA, 12-bit high speed ADC, 2×2 MIMO, etc. it competes with much more expensive SDRs. The $599 version uses the same software. The $599 gets you support from the manufacturer. It also does have an external clock input on the board. It’s visible in the pictures and documented in their wiki. They used a VCTCXO (+-250 ppb) which is also in the documentation. Did you read about it at all? I agree that they should have provided an inexpensive case option.
Btw. LimeSDR is fully open-hardware, so everything you want to know about HW design can be found in GitHub repository here: https://github.com/myriadrf/LimeSDR-USB
As four your questions about oscillator / clock, looking at that GitHub repo, you can find this:
Clock System
– 30.72MHz ±250 ppb on board VCTCXO
– Possibility to lock VCTCXO to external clock or tune VCTCXO by onboard DAC
– Programmable clock generator for the FPGA reference clock input or LMS PLLs
And if you look at schematics, there is separate U.FL connector on PCB just for clock.
LimeSDR 12 layer PCB
BladeRF 8 layer PCB
HackRF 4 layer PCB
RTL-SDR 2 layer PCB
I have no idea how the price point is so low, looking at the design of the PCB alone.
Case – make your own “Sick of Beige” case cost you like $10 at most for a
300mm x 300mm x 3.0mm Acrylic (PMMA) Plexiglass sheets. Or for better RF properties look for any aluminium box from China with internal dimensions equal to larger than the board $30 if you drill your own holes and can add nuts and bolts. e.g. https://www.aliexpress.com/item/130-90-50mm-Waterproof-power-supply-aluminum-housing-case-aluminum-enclosure-electric-meter-box-metal-distribution/1904070800.html
SMA Female to Ufl./IPX RG178 pigtail cables are cheap if you buy 10 at once you will get them for just over $1 each (including shipping).
Same for decent 700-2600MHz antennas you will get 5 cheaper than 4, say around $25 (with shipping).
Oh and in case you are asking why would you need 10 pigtails look at the PCB, there are 11 Ulf connectors on the PCB:
TXRF2_B
TXRF1_B
TXRF2_A
TXRF1_A
RXRF2_W
RXRF2_L
RXRF2_H
RXRF1_W
RXRF1_L
RXRF1_H
REFCLK
https://www.crowdsupply.com/img/f331/limesdr-frontcrop-1_jpg_open-graph.jpg
Set of 4x GSM / 3G / LTE antennas is much cheaper than $25, you can buy them for under $10 (with free shipping from China). E.g. here: http://www.ebay.com/itm/4pcs-GSM-Antenna-2-dbi-880-960Mhz-1710-1990MHz-SMA-Plug-male-ST-connector-new-/391006508674 (for $8 USD)
Only difference is that these antennas doesn’t cover 2.4 GHz band (those from LimeSDR does cover it). Do you know some similar cheap antennas which covers also 2.4 GHz band? If they will also cover 433 MHz band, even better, but I know this is not that simple…
This is the one that I was looking at which does cover 2.4GHz
https://www.aliexpress.com/item/5X-Superbat-excellent-performance-700-2600Mhz-4G-LTE-Antenna-5dbi-with-SMA-male-connector-wholesale-price/2034872682.html
Nice find. But I think that antenna will be tuned for 2.5 – 2.6 GHz (LTE-2600) range (will not cover whole advertised 1710 – 2620 MHz range that great), but maybe it will work on 2.4 GHz still well enough, who knows…
All cheap antennas come with no performance graphs so the only real way to know for sure is to buy one and test if it is fit for purpose ( https://www.rtl-sdr.com/characterizing-swr-antenna-noise-source-rtl-sdr/ ) . Then either blog about how bad or good it actually is.
I also found this one which is probably a PCB antenna inside, which would make me think that it might actually cover 700-2600MHz but it is a bit more pricey:
https://www.aliexpress.com/item/8dBi-GSM-3G-4G-Antenna-SMA-Connector-700-2600Mhz-omnidirectional-External-Antenna/32323500083.html