On Thu, Nov 03, 2005 at 11:40:42AM -0700, Robitaille, Michael wrote: > The project I am working is for remote sensing via an optic link. For the > proof of concept I am using ASK (ON/OFF Keying) modulation at low data rate > and low carrier frequencies (500Hz to 2.0 KHz - Yep real low). At a later > date it will be changed to different modulation technique and higher > frequencies to get the data rate up some. Based on my current > specification, none of the DB would be of much use so I am trying to use the > USRP w/o daughterboard's. > > Any insight/examples on how I can do this would be appreciated. > > I have been looking through all the documentation (Doxygen documents, usrp > header files, examples, Dawei Shen Tutorial) to find what I need but I am > coming up short. For instance, I can't find usage information for commands > like usrp.determine_rx_mux_value or options.rx_sugdev_spec and many more > that I have found being used in examples or mention in post on this board > (read_io). Could someone point me to where I can find > information/headers/code for these?
The code that defines determine_rx_mux_value is in gr-usrp/src/usrp.py It's pretty short. > The fist task that I am trying to do is make the example usrp_oscope.py and > usrp_fft.py work without the daughterboard. First I am not sure what inputs > these use and second I need to find out some information on some of the > function they use. The examples work but not sure how to connect the input > w/o daughter boards. You are going to need some kind of daughterboard to get access to the high-speed A/D and D/A inputs and output respectively. On the other hand, you may be able to just read a digital i/o pin for your very low data rate. The Basic Tx and Basic Rx daughterboards bring out 16 uncommitted digital i/o pins to headers. To read then periodically, you'd need to hack up some custom FPGA code. You might need to build a small amount of circuitry to inteface your analog signal to the 0 to 3.3 V levels the i/o pins expect. > Any help in how to modify these examples and where to find the information > on all the function/header/class would be appreciated. Almost all of the high level USRP functionality is defined in two C++ header files: usrp/host/lib/usrp_basic.h and usrp/host/lib/usrp_standard.h. Through a somewhat convoluted path, the public interfaces of those classes end being methods in the Python usrp.source_c and/or usrp.sink_c classes. Hope this helps. If not, please ask again. Eric _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
