LimeSDR-mini (was Re: confused by osmo-bts rsl.c:bts_supports_cm())

[Harald Welte]

Hi Neels,

On Tue, Sep 11, 2018 at 12:07:23AM +0200, Neels Hofmeyr wrote:
> On Mon, Sep 10, 2018 at 03:36:43PM +0200, Keith wrote:
> > but I am getting great value at the moment from the LimeSDR-mini and
> > osmo-trx-lms running on x86!!
> 
> Interesting how every other dev is reporting completely different results on
> lime. For some it seems to give pure satisfaction, while others seem to be but
> puzzled by the sheer uselessness of it?

I think it may be related to
a) the exact LimeSuite version you're using.

b) like any SDR, the stability/calibration of the clock you use. For the mini, this
   typically means using an external GPS-DO, which means you need to do a hardware
   re-work of moving one resistor, as well as using LimeSuite with patch/commit
   9977771c4af14731b5c2b32868b98e29ce7a3ce5
   Operating any BTS without a very good clock reference (GPS-DO,
   calibrated OCXO) is like playing lottery. You may get lucky some
   times, with some phones, but in most cases it will fail one way or
   another, in very subtle ways.

At sysmocom, it seems we have bricked all three LimeSDR-mini we have by
doing the usual gateware update using "LimeSuite master" last week or
so.  And no error at all was reported during the update.  The devices
simply are completely useless afterwards.

> I also still have that lime mini we got on the OsmoDevCon, still unused. Might
> give it a spin then?

I also bricked my personal LimeSDR-mini by duing a LimeUtil --update to install
the "latest" gateware (from June 2018!) like the three above-mentioned at sysmocom.

So whatever you do, I would recommend to be extremely careful with updating the firmware aka gateware.

-- 
- Harald Welte <laforge at gnumonks.org>           http://laforge.gnumonks.org/
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