Timing & Sources

GNU Radio
1

I’ve been through many GRC companion tutorials, which show how to get
various sources up and running, but what if I want to have an input
source
that has a straight line or parabola where the value varies based on a
time
from a 0 to 5 count?

Using existing blocks can I easily implement a formula input based on
the
time?

E.g. One thing I want to do is have trigger occurring every 5 seconds.
Is there a better way to do this then say having a
Source ‘Sinwave’ with a frequency of 1/5Hz
feeding along with a ‘Parameter’ (set to -1) into an ‘Add block’
which then feeds into a binary splitter?

2

On Sat, Jun 30, 2012 at 12:47:01PM +0930, Michael H. wrote:

I’ve been through many GRC companion tutorials, which show how to get various
sources up and running, but what if I want to have an input source that has a
straight line or parabola where the value varies based on a time from a 0 to 5
count?

Hi Michael,

you should realize that while that seems to be simple example, it’s a
very unusual thing to have in a flow graph :slight_smile:

That said, you can create a vector source (which you usually don’t), and
initialize this with something like ‘range(5)’ and set it to repeat.
Remember that in GRC, any initial values for your blocks don’t have to
be numericals, but simply any valid Python code, so even a list
comprehension is fine (i.e. anything that returns a vector).

MB

–
Karlsruhe Institute of Technology (KIT)
Communications Engineering Lab (CEL)

Dipl.-Ing. Martin B.
Research Associate

Kaiserstraße 12
Building 05.01
76131 Karlsruhe

Phone: +49 721 608-43790
Fax: +49 721 608-46071
www.cel.kit.edu

KIT – University of the State of Baden-Württemberg and
National Laboratory of the Helmholtz Association

3

Thanks again Martin! That one bit of knowledge has opened many doorways
for
me! :slight_smile:

Btw, I was looking for different ways to define a ramp input, or to send
a
pulse at different times…
and was looking at how I could possibly just record a pulse into a file
then send it at certain repeat times…

As opposed to chopping a cosine with a vector of 1s and 0s or
something…