Can't connect to USRP2 using UHD driver

I can’t connect to the USRP2 using the latest version of the UHD
driver from the git repository.

I am using Fedora 12 64-bit, I’ve disabled the firewall, and built the
UHD driver from sources.

I’ve also configured the network interface and here is the result of

eth2 Link encap:Ethernet HWaddr 00:0C:29:5D:EC:A6
inet addr: Bcast:
inet6 addr: fe80::20c:29ff:fe5d:eca6/64 Scope:Link
RX packets:26 errors:0 dropped:0 overruns:0 frame:0
TX packets:42 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:7392 (7.2 KiB) TX bytes:5169 (5.0 KiB)

When I type the following command:

uhd_find_devices --args addr=

I get No UHD Devices Found

I’m using the latest UHD firmware downloaded from the Ettus website.
What shoudl I do?

Elvis D.

I found the solution. I had to write both the UHD FPGA and
firmware images onto the SD card. Once I did that, it worked cleanly,
and I was able to find the USRP2 device.

$ uhd_find_devices

– UHD Device 0

type: usrp2

I’ve summarized the steps below, and will update the GNU Radio wiki in a

Best regards,

Elvis D.

Technote GNU-Radio-3.3-005: How to install the USRP2 UHD driver for
Fedora-12 x86 64-bit


This document describes how to install the USRP2 UHD driver for
Fedora-12 x86 64-bit operating system.


Step 01.00: Download required packages for building the UHD driver.

Step 01.01: Download and build CMake 2.8.2.

Download CMake from

$ cd cmake-2.8.2
$ ./configure
$ make -j 4
$ sudo make install

Step 02.00: Download the UHD sources from the Ettus research git

$ git clone git://

Step 02.01: Build the UHD driver.

$ cd uhd/host
$ mkdir build
$ cd build
$ cmake …/
$ make
$ make test
$ sudo make install

Modify your .bashrc file to ensure that is in your

export LD_LIBRARY_PATH="/usr/local/lib:$LD_LIBRARY_PATH"

Step 03.00: Download the GNU Radio sources from the GNU Radio git

$ git clone
$ cd gnuradio
$ git branch --track next origin/next
$ git checkout next
$ ./bootstrap
$ ./configure
$ make -j 4
$ make check
$ sudo make install

Step 04.00: Download the pre-built firmware images.

Go to

and download the following FPGA and firmware image:

u2_rev3_uhd_20100706.bin (FPGA)
txrx_uhd_20100706.bin (firmware)

Step 05.00: Update the USRP2 firmware image on the SD card.

Step 05.01: Locate the correct device for the SD card

Insert the SD card into the SD card reader slot of your computer.

Run gparted, the graphical disk partitioning utility to quickly
determine which device the SD card is connected. Usually /dev/sda would
be your primary hard disk, and /dev/sdb would be the SD card.

Step 05.02: Write the UHD FPGA and firmware images to the SD Card

Write the new UHD FPGA image to the SD card:

$ cd uhd/host/utils
$ sudo ./ --dev=/dev/sdb

Write the new UHD firmware image to the SD card:

$ sudo ./ --dev=/dev/sdb

Step 05.03: To switch back to the original raw ethernet drivers, write
the following USRP2 FPGA and firmware images to the SD Card

Write the raw ethernet FPGA image to the SD card:

$ cd uhd/host/utils
$ sudo ./ --dev=/dev/sdb

Write the raw ethernet with WBX firmware image to the SD card:

$ sudo ./ --dev=/dev/sdb

Step 06.00: Configure the network interface.

Step 06.01: Assign a static IP address to the host computer ethernet
network interface card, connected to the USRP2.

Network configuration for host computer ethernet interface to the USRP2:

IPv4 address:
Subnet mask:

In the case of Fedora 12 running inside a VMware image, the interface
would be eth2.

Step 06.02: Configure the firewall to allow access to the USRP2.

Go to System -> Administration -> Firewall configuration, and set the
user skill to Expert.

Go to the Trusted Interfaces option in the tree view, and check eth2,
and click on the Apply button.

This will enable UDP communications with the USRP2.

Step 07.00: Test communication with the USRP2 using the UHD driver.

Type the following command to enumerate all the USRP2 devices connected
to the network:

$ uhd_find_devices

– UHD Device 0

type: usrp2

Related Topics


Related Links

  1. UHD - Build Guide.

  2. UHD - General Application Notes.

  3. UHD - USRP2 Application Notes.

  4. UHD - Daughterboard Application Notes.

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