Table of Contents
By default, the USRP1 uses the FPGA image with 2 DDCs and 2 DUCs. However, a device address parameter can be used to override the FPGA image selection to use an alternate or a custom FPGA image. See the images application notes for installing custom images.
Example device address string representations to specify non-standard firmware and/or FPGA images:
fpga=usrp1_fpga_4rx.rbf -- OR -- fw=usrp1_fw_custom.ihx -- OR -- fpga=usrp1_fpga_4rx.rbf, fw=usrp1_fw_custom.ihx
The USRP1 has multiple daughterboard slots, known as slot A and slot B. The subdevice specification can be used to select the daughterboard and subdevice for each channel. For daughterboards with one one subdevice, the subdevice name may be left blank for automatic selection.
Ex: The subdev spec markup string to select a WBX on slot B. Notice the use of the blank subdevice name for automatic selection.
B: -- OR -- B:0
Ex: The subdev spec markup string to select a BasicRX on slot B. Notice that the subdevice name is always specified in the 3 possible cases.
B:AB -- OR -- B:A -- OR -- B:B
The USRP1 FPGA does not have the necessary space to support the advanced streaming capabilities that are possible with the newer USRP devices. Some of these features are emulated in software to support the API.
Note: These emulated features rely on the host system's clock for timed operations, and therefore may not have sufficient precision for the application.
On Linux, udev handles USB plug and unplug events. The following commands create a udev rule for the USRP1 so that non-root users may access the device:
echo 'ACTION=="add", BUS=="usb", SYSFS{idVendor}=="fffe", SYSFS{idProduct}=="0002", MODE:="0666"' > tmpfile
sudo chown root.root tmpfile
sudo mv tmpfile /etc/udev/rules.d/10-usrp.rules
sudo udevadm control --reload-rules
On Windows, a driver must be installed the first time the USRP1 is attached to the host computer. A download link for this driver can be found on the UHD wiki page. Download and unpack the driver, and direct the Windows driver install wizard to the .inf file.
The new external clock needs to be a square wave between +7dBm and +15dBm
For the correct clock settings, call usrp->set_master_clock_rate(EXT_CLOCK_FREQUENCY) before any other parameters are set in your application.