Re: [Discuss-gnuradio] Behaviour of gs-osmosdr when multiple devices in the source

[Alexandru Csete]

On Wed, Oct 23, 2013 at 10:33 PM, Marcus D. Leech <address@hidden> wrote:
> On 10/23/2013 04:19 PM, Alexandru Csete wrote:
>>
>> Hi Marcus,
>>
>> I believe the behavior is different from source to source and
>> basically depends on whether the source block takes advantage of the
>> start/stop methods. For example, the Funcube Dongle Pro and Pro+
>> blocks are gnuradio audio source blocks that use the start and stop
>> methods and therefore will not start reading samples until the flow
>> graph is started. In other words, two funcube dongles will be more or
>> less synchronized, except for the clock differences. I think it is the
>> same for the UHD sources.
>>
>> On the other hand, I have observed that if I create an rtlsdr source
>> block, after a few seconds it will start spitting OOOOOO out to the
>> terminal until I start the flow graph. This indicates that the rtlsdr
>> source is started as soon as it is created.
>>
>> Alex
>
> Interesting.  I'll observe, out loud, that it would be useful for my current
> coherence testing if the behaviour could be closer to "roughly
> synchronized".
>   Not sure how easy that is to do for RTLSDR.

I think you can create one multi-channel source using 2 separate
devices. That may get you close. I haven't tried this feature though
so I don't know how it works.

Alex