[Discuss-gnuradio] help -- how to implement transmitting periodic on/off tones

[Steve Mcmahon]

Hello:

I have a USRP2 board and a WBX daughterboard. I am trying to implement a scheme 
where a single-tone sine wave (at frequencies between 1 kHz and 10 kHz) is 
transmitted intermittently. Specifically, time is divided into intervals, 
defined by the user on the command line, typically of values such as 200 ms or 
500 ms or 1s. When invoked, the flow graph (the Python script) would transmit 
nothing (all zeros) during the first time interval, then transmit the tone 
during the second time interval, then transmit nothing (all zeros) during the 
third and fourth and fifth time intervals, then transmit the tone during the 
sixth time interval, then transmit nothing (all zeros) during the seventh time 
interval, and then stop and end.

How in the world could I implement this? I feel like it'd be hard to do, but 
maybe it's actually easy. Would I need to use a timer in Python to set what 
gets transmitted at the start of each interval duration? Any help would be very 
much appreciated, as I am still somewhat new to GNU Radio and Python. Thanks 
for your help, everyone.

Steve McMahon