Re: [Discuss-gnuradio] OOT Block to Automatically adjust Transmit Gain

[Tellrell White]

In the attached flow graph, I've created a block, "gain setter" that takes in a number of input items and after the input items reach a certain amount, the block will issue a command to the ursp sink to change the gain to a certain value. I basically did this using a loop. However, it doesn't seem like the gain of the signal changes according to the freq sink plot of the received signal. Any ideas??

On Thu, Jul 13, 2017 at 2:48 PM, Bakshi, Arjun <address@hidden> wrote:

Couldn't figure out how to reply from the digest, so I'm making a new post. New to this.

Original message/context:

==============================

From: Tellrell White

I'm currently in the process of creating a block in python that does two things; takes in? a certain number of input items, and once it reaches a certain number of input items 2) it sends a command to the UHD USRP sink block to adjust its gain by a certain amount.

I have a few questions. 1) Is it even possible to create a single block that can accomplish both these tasks? 2) How exactly do I make this block issue the command to adjust the gain after it receives a certain number of values??Below is some code that I currently have constructed for this purpose. I'm pretty new to python so I'm sure this code is probably not the most efficient way but any suggestions are welcome.

===============================

Hey Tellrell,

1) I think it can be achieved using 1 block. The block will need to output a message with "gain" and the gain value whenever the input matches your condition. Connect the output message port to the USRP sink's command port. Message should be a pmt that looks something like ("gain", value).

More info on the command port: https://gnuradio.org/doc/doxygen/page_uhd.html#uhd_command_syntax

2) I went ahead and implemented something as an example. Increases gain upto a limit and then starts over again. See attached code, xml for block, rxed signal plot, and flowgraph pic.

I'm new to this too, so hopefully other will correct my mistakes.

Regards,

AB

_______________________________________________
Discuss-gnuradio mailing list
address@hidden
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

gain_test.grc
Description: application/gnuradio-grc