Re: [Discuss-gnuradio] turn off DC offset

[Michael Dickens]

Thank you, Julian ... that's the issue here I bet!

Simona is running GR 3.7.14.4, which contains a bug in gr-uhd's GRC interface 
where the "set_auto_dc_offset" function is executed only if its argument is 
"True". We fixed it here < 
https://github.com/gnuradio/gnuradio/commit/fc3eaf1414c192294281eef0a009359d1c913d99
 > to take any argument provided -- though only "True" or "False" will work -- 
and this fix is part of the 3.7.14.5 release.

Simona - Can you update GR to the 3.7.14.5 release? Doing so and using "True" / 
"False" (without ""s) in the UHD GRC blocks will hopefully resolve your issue. 
- MLD

On Tue, Jul 30, 2019, at 12:44 PM, Julian Arnold wrote:
> Hey,
> 
> I've had a similar issue with a 3.7 version so maybe this helps.
> 
> For me, no other value than "True" (without "") would generate a call to 
> "set_auto_dc_offset()" in the GRC generated python script ("top_block.py").
> 
> So, in order to disable DC offset tracking, a quick workaround would be 
> to set "Enable DC Offset Corrections" to "True". This adds the desired 
> call to "set_auto_dc_offset()" to your "top_block.py". Now you only need 
> to manually change "True" to "False" in "top_block.py" and DC offset 
> tracking should be disabled. Remember to not regenerate the flow-graph 
> after making those changes as otherwise GRC will override your changes.
> 
> Alternatively, you can of course always simply add the line 
> self.uhd_usrp_source_0.set_auto_dc_offset(False, 0)
> to your script without using GRC.
> 
> Hope this helps.
> Cheers,
> Julian