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Connect Raspberry Pi3 B+ to USRP N200 via Gigabit Ethernet Cable Cat5e and higher

kazemc

Hi everyone,

Question:

I want to know, can we have direct communication between USRP N200 and Raspberry Pi3 B+ through Gigabit Ethernet cable?

I know for Raspberry Pi3, it wasn't possible due to weakness of LAN port since it wasn't support Gigabit communication, but for Raspberry Pi3 B=, it is claimed that has the capability of Gigabit communication with all those improvements.

In Raspberry Pi3, it was mentioned in few forums that needs to use USB adaptor from Gigabit Ethernet cable though I haven't tested it myself. Has anyone here tried this direct communication before? (either via USB or Ethernet)

Purpose:

I need it for a project in which we want to activate each USRP N200 via Raspberry Pi 3 B+ with use of GNU radio to transfer short data stream (short MP4 or MP3)  from node to node. (I have already ordered Raspberry Pi3 B+ and will receive them soon).

 

Current experiment:

At the moment I have tried the communication between USRP N200 and Raspberry Pi3 via a D-Link Gigabit switch and able to detect and communicate with USRP. The operating system is Ubuntu Mate and so far no problem except higher delay which is normal since the Raspberry has lower processor power compared to normal PCs.

 

Will be great if anyone can give some tips.

Appreciate for your help,

Kazem

Parents

  • Almost all 1000mbps ethernet ports are also 100mbps capable. So when you plug your pi into a switch that does gigabit, that port will be downgraded to 100mbps automatically. If you want to remove the switch, the USRP N200 will automatically downgrade its port to 100mbps and happily communicate with the raspberry.

     

    Also, in the time when there wasn't gigabit ethernet yet, you had to make sure that you used a crossover cable between two devices that would normally connect to a switch. This is not necessary when one of them is Gigabit capable: All gigabit ports support automatic adjustment to whatever cable you choose.

     

    But due to the way the pi is builtup the pi will not be able to achieve very high speeds. But that's not what it was made for.

     

    In short: I expect no problems.

  • in reply to rew

    Hi Roger,

    Thanks for your reply.

    Tomorrow I will go to my lab and test direct communication from USRP to Raspberry Pi 3 (since I haven't received Raspberry Pi3 B+ yet). I will let you know the results by tomorrow. But I am not sure that can work with Raspberry pi3 due to very low speed of LAN port and circuit. (let's be optimistic ;-) )

    Tnx

  • in reply to kazemc

    I just researched what your USRP N200 is.... It is capable of sampling and transmitting 50Msampes per second. If those are 8bit, that's 50 Mbytes per second. For this you need gigabit ethernet, simply because it doesn't fit on 100mbps.

     

    Maybe the pi at $35 is not a good match for the $1500+ SDR? Now you're limiting the SDR to a small part of its capability when it costs more than 10 times more than your processing unit. As much as I think the pi is a very good device, and has plenty of processing power for a lot of things, here the "only USB for outside IO" limitation is quite limiting.

  • in reply to rew

    Hi Roger,

    I tested the direct Gigabit Ethernet cable to Raspberry Pi3 and it did not even turn ON. They seems not to be compatible. I have ordered USB3 adapter to Gigabit Ethernet to test this direct connection via USB port, since USB can cover over 100Mbps. I know the Raspberry Pi3 processor is not as strong as normal PCs but for the current project I can't use over 13 laptop or PCs due to monetary limitations, so I have no choice except use Raspberry pi3 B+.

     

    For the moment this direct communication without Ethernet switch is the issue.  

Reply
  • in reply to rew

    Hi Roger,

    I tested the direct Gigabit Ethernet cable to Raspberry Pi3 and it did not even turn ON. They seems not to be compatible. I have ordered USB3 adapter to Gigabit Ethernet to test this direct connection via USB port, since USB can cover over 100Mbps. I know the Raspberry Pi3 processor is not as strong as normal PCs but for the current project I can't use over 13 laptop or PCs due to monetary limitations, so I have no choice except use Raspberry pi3 B+.

     

    For the moment this direct communication without Ethernet switch is the issue.  

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