On Wed, Sep 21, 2016 02:22:30 +0000, Leif Asbrink <leif@sm5bsz.com> wrote:
Other alternatives that you can use with Linrad under Linux are: Airspy, SdrPlay, BladeRF, Afedri, ELAD FDM-S1, Perseus, CloudIQ, Excalibur and more.
Hi Leif, I hope you have had an enjoyable summer there in the beautiful land of the midnight sun. I was curious if the LimeSDR is on your radar for possible LinRad support?? It won't be shipping until late November, but it has some interesting specifications (for one, it's a transceiver, not just a receiver). It looks promising and affordable, despite the fact it appears to target the Internet of Things market rather than amateur radio applications. Here are some links; https://www.crowdsupply.com/lime-micro/limesdr http://www.limemicro.com/ 73, KD6EKQ John -- John C. Peterson, KD6EKQ mailto:jcp@eskimo.com San Diego, CA U.S.A
Hello John,
I was curious if the LimeSDR is on your radar for possible LinRad support?? It won't be shipping until late November, but it has some interesting specifications (for one, it's a transceiver, not just a receiver). https://www.crowdsupply.com/lime-micro/limesdr http://www.limemicro.com/
I find no information about the tuner chip. It seems to me that this product is intended to do all processing in the on-board fpga. That does not fit Linrad which is designed to operate on an unprocessed baseband signal. The only need for an fpga when interfacing to Linrad is managing the USB link and possibly some resampling if the sampling rate of the ADC is too high for the USB link, plus, of course managing the control signals to the tuner chip. (And corresponding for the transmit channel.) In case someone else develops fpga code that makes a decent SDR out of the LimeSDR with an appropriate library with an API that can reasonably easily be called from a C program I might become interested. I am not going to write fpga code myself - and also not a library to provide an API. 73 Leif
On Thu, Sep 22, 2016 at 03:16:55AM +0200, Leif Asbrink wrote:
Hello John,
I was curious if the LimeSDR is on your radar for possible LinRad support?? It won't be shipping until late November, but it has some interesting specifications (for one, it's a transceiver, not just a receiver). https://www.crowdsupply.com/lime-micro/limesdr http://www.limemicro.com/
Hello Leif, Work has kept me busy lately and I have not had a chance to reply until now. I did find some time to do more reading on the LimeSDR over the weekend. Here is what I found.
I find no information about the tuner chip. It seems to me that this product is intended to do all processing in the on-board fpga. [... snip ...]
You are right. It is like the newest generation of SDRs (e.g. FlexRadio) where the FPGA does everything to provide a stand alone radio. I agree, that does take most of the fun out of it for those of us that like to "tinker". However, there appears to be some hope. I found this blog post about using the LimeSDR with gqrx; https://myriadrf.org/blog/first-tests-limesdr-gqrx/
In case someone else develops fpga code that makes a decent SDR out of the LimeSDR with an appropriate library with an API that can reasonably easily be called from a C program I might become interested. I am not going to write fpga code myself - and also not a library to provide an API.
It looked to me like this "piece of the puzzle" does exist, it's a "middleware" framework called SoapySDR. The blog post above made some comments to the effect that not everything has been implemented just yet (tuning for HF frequencies was mentioned). Then again, the article is dated May 2016, so things might have improved since then??? More on SoapySDR; https://github.com/pothosware/SoapySDR/wiki https://myriadrf.org/blog/limesuite-driver-architecture/ Getting Linrad to work with SoapySDR would require some effort for sure, but another benefit is a common API interface to other devices like the Realtek dongles, etc. (SoapySDR already supports a number of other popular devices). Some other threads on the LimeSDR for amateur radio applications: https://amsat-uk.org/2016/03/14/listen-iss-raspberry-pi-3-limesdr/ https://discourse.myriadrf.org/t/limesdr-as-a-amateur-radio-transciever/450 Skol! de KD6EKQ -- John C. Peterson, KD6EKQ mailto:jcp@eskimo.com San Diego, CA U.S.A
participants (2)
-
John C. Peterson -
Leif Asbrink