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diff --git a/host/docs/usrp2.rst b/host/docs/usrp2.rst new file mode 100644 index 000000000..bc4ea0e44 --- /dev/null +++ b/host/docs/usrp2.rst @@ -0,0 +1,243 @@ +======================================================================== +UHD - USRP2 Application Notes +======================================================================== + +.. contents:: Table of Contents + +------------------------------------------------------------------------ +Building firmware and FPGA images +------------------------------------------------------------------------ + +^^^^^^^^^^^^^^^^^^ +FPGA Image +^^^^^^^^^^^^^^^^^^ +Xilinx ISE 10.1 and up is required to build the FPGA image for the USRP2. +The build requires that you have a unix-like environment with make. +Make sure that xtclsh from the Xilinx ISE bin directory is in your $PATH. + +Run the following commands: +:: + + cd <uhd-repo-path>/fpga/usrp2/top/u2_rev3 + make -f Makefile.udp bin + +*The image file will be ./build/u2_rev3.bin* + +^^^^^^^^^^^^^^^^^^ +Firmware Image +^^^^^^^^^^^^^^^^^^ +The Microblaze GCC compiler from the Xilinx EDK is required to build the firmware. +The build requires that you have a unix-like environment with autotools and make. +Make sure that mb-gcc from the Xilinx EDK/microblaze directory is in your $PATH. + +Run the following commands: +:: + + cd <uhd-repo-path>/firmware/microblaze + ./boostrap + ./configure --host=mb + make + +*The image file will be ./usrp2/usrp2_txrx_uhd.bin* + +------------------------------------------------------------------------ +Load the images onto the SD card +------------------------------------------------------------------------ +**Warning!** +Use the usrp2_card_burner.py with caution. If you specify the wrong device node, +you could overwrite your hard drive. Make sure that --dev= specifies the SD card. + +Use the *--list* option to get a list of possible raw devices. +The list result will filter out disk partitions and devices too large to be the sd card. +The list option has been implemented on Linux, Mac OS X, and Windows. + +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Use the card burner tool (unix) +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +:: + + sudo <prefix>/share/uhd/utils/usrp2_card_burner_gui.py + + -- OR -- + + cd <prefix>/share/uhd/utils + sudo ./usrp2_card_burner.py --dev=/dev/sd<XXX> --fpga=<path_to_fpga_image> + sudo ./usrp2_card_burner.py --dev=/dev/sd<XXX> --fw=<path_to_firmware_image> + +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Use the card burner tool (windows) +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +:: + + <path_to_python.exe> <prefix>/share/uhd/utils/usrp2_card_burner_gui.py + + +------------------------------------------------------------------------ +Setup networking +------------------------------------------------------------------------ +The USRP2 only supports gigabit ethernet, and +will not work with a 10/100 Mbps interface. +Because the USRP2 uses gigabit ethernet pause frames for flow control, +you cannot use multiple USRP2s with a switch or a hub. +It is recommended that each USRP2 be plugged directly into its own +dedicated gigabit ethernet interface on the host computer. + +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Setup the host interface +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +The USRP2 communicates at the IP/UDP layer over the gigabit ethernet. +The default IP address of the USRP2 is **192.168.10.2** +You will need to configure the host's ethernet interface with a static IP address to enable communication. +An address of **192.168.10.1** and a subnet mask of **255.255.255.0** is recommended. + +**Note:** +When using the UHD, if an IP address for the USRP2 is not specified, +the software will use UDP broadcast packets to locate the USRP2. +On some systems, the firewall will block UDP broadcast packets. +It is recommended that you change or disable your firewall settings. + +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Multiple device configuration +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +As described above, you will need one ethernet interface per USRP2. +Each ethernet interface should have its own subnet, +and the corresponding USRP2 device should be assigned an address in that subnet. +Example: + +**Configuration for USRP2 device 0:** + +* Ethernet interface IPv4 address: 192.168.10.1 +* Ethernet interface subnet mask: 255.255.255.0 +* USRP2 device IPv4 address: 192.168.10.2 + +**Configuration for USRP2 device 1:** + +* Ethernet interface IPv4 address: 192.168.20.1 +* Ethernet interface subnet mask: 255.255.255.0 +* USRP2 device IPv4 address: 192.168.20.2 + +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Change the USRP2's IP address +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +You may need to change the USRP2's IP address for several reasons: + +* to satisfy your particular network configuration +* to use multiple USRP2s on the same host computer +* to set a known IP address into USRP2 (in case you forgot) + +**Method 1:** +To change the USRP2's IP address +you must know the current address of the USRP2, +and the network must be setup properly as described above. +Run the following commands: +:: + + cd <prefix>/share/uhd/utils + ./usrp_addr_burner --addr=192.168.10.2 --new-ip=192.168.10.3 + +**Method 2 (Linux Only):** +This method assumes that you do not know the IP address of your USRP2. +It uses raw ethernet packets to bypass the IP/UDP layer to communicate with the USRP2. +Run the following commands: +:: + + cd <prefix>/share/uhd/utils + sudo ./usrp2_recovery.py --ifc=eth0 --new-ip=192.168.10.3 + +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Debugging networking problems +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +**Disable the firewall:** +If uhd_find_devices gives you nothing +but uhd_find_devices --args addr=192.168.10.2 yeilds a discovered device, +then your firewall may be blocking replies to UDP broadcast packets. + +**Ping the USRP2:** +The USRP2 will reply to icmp echo requests. +:: + + ping 192.168.10.2 + +**Monitor the USRP2:** +You can read the serial port on the rear of the USRP2 +to get debug verbose from the embedded microcontroller. +Use a standard USB to 3.3v-level serial converter at 230400 baud. +The microcontroller prints useful information about IP addresses, +MAC addresses, control packets, and fast-path settings. + +**Monitor the host network traffic:** +Use wireshark to monitor packets sent to and received from the USRP2. + +------------------------------------------------------------------------ +Addressing the device +------------------------------------------------------------------------ + +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Single device configuration +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +A USRP2 can be identified though its IPv4 address or resolvable hostname. +The USRP2 device is referenced through the "addr" key in the device address. +Use this addressing scheme with the *simple_usrp* interface. + +The device address string representation for a USRP2 with IPv4 address 192.168.10.2 + +:: + + addr=192.168.10.2 + +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Soft-MIMO configuration +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +In a soft-mimo configuration, each USRP2 must have a unique IPv4 address (per computer) +and be attached to its own dedicated network port. +The value for the addr key is a white-space separated list +of IPv4 addresses or resolvable hostnames. +The first address in the list will represent channel 0, +the second channel 1, and so on... +Use this addressing scheme with the *mimo_usrp* interface. + +The device address string representation for 2 USRP2s with IPv4 addresses 192.168.10.2 and 192.168.20.2 +:: + + addr=192.168.10.2 192.168.20.2 + +------------------------------------------------------------------------ +Resize the send and receive buffers +------------------------------------------------------------------------ +It may be useful increase the size of the socket buffers to +move the burden of buffering samples into the kernel, or to +buffer incoming samples faster than they can be processed. +However, if you application cannot process samples fast enough, +no amount of buffering can save you. + +By default, the UHD will try to request a reasonably large buffer size for both send and receive. +A warning will be printed on instantiation if the actual buffer size is insufficient. +See the OS specific notes below: + +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +OS specific notes +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +On linux, the maximum buffer sizes are capped by the sysctl values +**net.core.rmem_max** and **net.core.wmem_max**. +To change the maximum values, run the following commands: +:: + + sudo sysctl -w net.core.rmem_max=<new value> + sudo sysctl -w net.core.wmem_max=<new value> + +Set the values permanently by editing */etc/sysctl.conf* + +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Device address params +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +To manually set the size of the buffers, +the usrp2 will accept two optional parameters in the device address. +Each parameter will accept a numeric value for the number of bytes. + +* recv_buff_size +* send_buff_size + +Example, set the args string to the following: +:: + + addr=192.168.10.2, recv_buff_size=100e6 |