Re: GPIO lines on RPi4

2020-07-17 Thread jean-michel.fri...@femto-st.fr
To complete this demonstration of running a TCP server from within the 
GNU Radio Companion flowchart without modifying the generated Python code,
and correcting a mistake in the post below so that I can also update the Signal
Source frequency, I have uploaded
 
http://jmfriedt.org/2020-07-17-140636_2704x1050_scrot_ann.png 

(and removed the erroneous screenshots cited in the previous messages).

Gwenhael Goavec explained to me the mistake I was doing: when calling tt=t.t()
(since t is the Id of the flowchart) from the thread, I was creating a new 
instance of the whole flowchart, whose frequency variable did not match the 
one defining the frequency source signal that was being displayed.
Instead of creating a new instance of the flowchart in the thread, the argument 
"self"
must be provided when creating the thread. Then, the variables and methods from 
the
calling class can be accessed and indeed, changing the signal source frequency 
does
lead to a change in the displayed spectrum.

JM

--
JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
25000 Besancon, France

June 30, 2020 10:10 AM, jean-michel.fri...@femto-st.fr wrote:

> Thanks to this comment, I ended up finding a solution to call a thread
> running a TCP/IP server able to control the variables from the main
> processing flowchart, without modifying manually the generated Python for a Qt
> application.
> A screenshot, which I hope is self-explanatory, illustrating this process is 
> at
> http://jmfriedt.org/2020-06-30-083722_2704x1050_scrot.png
> 
> However I am facing a surprising result.
> I initially (see above) created a signal source, set its frequency to a 
> variable flo, 
> checked with a slider that changing flo did change the output frequency, 
> removed the 
> slider and set the signal source flo from my server. No change in the 
> frequency output.
> 
> So I went back to my initial setup in which I change not only the source 
> signal
> frequency but also the receiver hardware LO frequency of the B210, keeping 
> the TX LO
> fixed. And surely enough both a spectrum analyzer and the coupled output from 
> the
> B210 TX to the RX show the signal shifting.
> 
> Screenshots at
> http://jmfriedt.org/2020-06-30-095336_2704x1050_scrot.png show that the 
> callback function
> for the source frequency or LO frequency are exactly the same and so are the 
> server handling
> functions, while
> http://jmfriedt.org/2020-06-30-095712_2704x1050_scrot.png shows that the B210 
> TX frequency
> only changes when tuning the hardware LO, not the signal source LO.
> 
> Is there some signal that needs to be sent to the signal source beyond
> self.analog_sig_source_x_0.set_frequency(self.flo)
> to tell it to change frequency ?
> 
> Thanks, JM
> 
> --
> JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
> 25000 Besancon, France
> 
> June 22, 2020 1:25 PM, "Marcus Müller"  wrote:
> 
>> It gets even better:
>> 
>> We've launched a feature in 3.8.1.0 (and on master before that, as we do
>> with any feature that ends up in a maintenance release) that we hope
>> doesn't come back to bite us due to enabling unclean design. But, we
>> must build best practices so that it doesn't go unused, either, so:
>> 
>> Assuming you're using GNU Radio 3.8.1.0 (or later, once we release
>> something), you can make use of the "Python Snippets" in GRC.
>> 
>> Cheers,
>> Marcus
>> 
>> On 18/06/2020 23.17, Marcus D. Leech wrote:
>> 
>>> On 06/18/2020 03:54 PM, jean-michel.fri...@femto-st.fr wrote:
>> 
>> My approach:
>> * build your grc chart from GNU Radio Companion and generate the .py file
>> * edit the py file and import pygpio
>> * play with the RPi4 GPIO in your python script.
>> 
>> See attached script, with a python server included in the Python script
>> to control an RF switch from a GNU Octave TCP/IP client talking to the
>> Python
>> TCP/IP server.
>> 
>> I am presenting this approach to hardware control at
>> http://jmfriedt.free.fr/sdra_radar.pdf
>> 
>> JM
>>> If you use "Python Module" block, you can write a lot of
>>> non-GnuRadio-esque python, import anything you want, etc, etc. No editing
>>> of the output python required, necessarily.
>> 
>> --
>> JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
>> 25000 Besancon, France
>> 
>> June 18, 2020 9:40 PM, "Da Fy"  wrote:
>>> Hi All, does anyone have an example of how to control GOIO lines on
>>> the RPi4 from within a GRC
>>> flowgraph. I’m guessing it’s an OOT module.
>>> 
>>> I need to generate a signal of a few 100Hz & control GPIO lines at
>>> various points though the cycle.
>>> 
>>> Alternatively, I could generate the signal & lines with external
>>> hardware & read them with
>>> GnuRadio.
>>> 
>>> Tnx, Dave



Re: GPIO lines on RPi4

2020-06-30 Thread jean-michel.fri...@femto-st.fr
Thanks to this comment, I ended up finding a solution to call a thread
running a TCP/IP server able to control the variables from the main
processing flowchart, without modifying manually the generated Python for a Qt
application.
A screenshot, which I hope is self-explanatory, illustrating this process is at
http://jmfriedt.org/2020-06-30-083722_2704x1050_scrot.png

However I am facing a surprising result.
I initially (see above) created a signal source, set its frequency to a 
variable flo, 
checked with a slider that changing flo did change the output frequency, 
removed the 
slider and set the signal source flo from my server. No change in the frequency 
output.

So I went back to my initial setup in which I change not only the source signal
frequency but also the receiver hardware LO frequency of the B210, keeping the 
TX LO
fixed. And surely enough both a spectrum analyzer and the coupled output from 
the
B210 TX to the RX show the signal shifting.

Screenshots at
http://jmfriedt.org/2020-06-30-095336_2704x1050_scrot.png show that the 
callback function
for the source frequency or LO frequency are exactly the same and so are the 
server handling
functions, while
http://jmfriedt.org/2020-06-30-095712_2704x1050_scrot.png shows that the B210 
TX frequency
only changes when tuning the hardware LO, not the signal source LO.

Is there some signal that needs to be sent to the signal source beyond
self.analog_sig_source_x_0.set_frequency(self.flo)
to tell it to change frequency ?

Thanks, JM

--
JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
25000 Besancon, France

June 22, 2020 1:25 PM, "Marcus Müller"  wrote:

> It gets even better:
> 
> We've launched a feature in 3.8.1.0 (and on master before that, as we do 
> with any feature that ends up in a maintenance release) that we hope 
> doesn't come back to bite us due to enabling unclean design. But, we 
> must build best practices so that it doesn't go unused, either, so:
> 
> Assuming you're using GNU Radio 3.8.1.0 (or later, once we release 
> something), you can make use of the "Python Snippets" in GRC.
> 
> Cheers,
> Marcus
> 
> On 18/06/2020 23.17, Marcus D. Leech wrote:
> 
>> On 06/18/2020 03:54 PM, jean-michel.fri...@femto-st.fr wrote:
>>> My approach:
>>> * build your grc chart from GNU Radio Companion and generate the .py file
>>> * edit the py file and import pygpio
>>> * play with the RPi4 GPIO in your python script.
>>> 
>>> See attached script, with a python server included in the Python script
>>> to control an RF switch from a GNU Octave TCP/IP client talking to the
>>> Python
>>> TCP/IP server.
>>> 
>>> I am presenting this approach to hardware control at
>>> http://jmfriedt.free.fr/sdra_radar.pdf
>>> 
>>> JM
>> 
>> If you use "Python Module" block, you can write a lot of
>> non-GnuRadio-esque python, import anything you want, etc, etc.  No editing
>> of the output python required, necessarily.
>> 
>>> --
>>> JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
>>> 25000 Besancon, France
>>> 
>>> June 18, 2020 9:40 PM, "Da Fy"  wrote:
>> 
>> Hi All, does anyone have an example of how to control GOIO lines on
>> the RPi4 from within a GRC
>> flowgraph. I’m guessing it’s an OOT module.
>> 
>> I need to generate a signal of a few 100Hz & control GPIO lines at
>> various points though the cycle.
>> 
>> Alternatively, I could generate the signal & lines with external
>> hardware & read them with
>> GnuRadio.
>> 
>> Tnx, Dave



Re: GPIO lines on RPi4

2020-06-27 Thread jean-michel.fri...@femto-st.fr
I am definitely not knowledgeable about Python so I might be missing
the basics: as I want to include a TCP server for tuning the acquisition
parameters, it seems to me (but I might be wrong) that the Python Module
is more appropriate than the Python Snippet which seems to add a piece
of code to the main() Python flowgraph function.
The TCP server in the Python Module I have written must change the USRP LO
frequency so in my Python Module I
import t
since t is my GRC flowchart name and I create tt=t.t() which allows me to
change e.g. the LO frequency variable f with tt.f=tt.f+1 or change the
LO frequency itself by calling tt.set_f(tt.f). This is all good in a CLI 
application
as the one running on the RPi4, and working nicely.
However for educational purposes I wanted to demonstrate the same principle with
a Qt Application and in this case I get the error message
QWidget: Must construct a QApplication before a QWidget
which I assume is due to the definition of the class
class t(gr.top_block, Qt.QWidget):
requiring a Qt.QWidget when I define tt=t.t() which is not yet defined as
Qt.QApplication.setGraphicsSystem(style)
qapp = Qt.QApplication(sys.argv)

Is there a proper way of accessing the variables and the functions of the main 
GRC
flowchart from my Python Module, also applicable in the case of a Qt 
Application ?

Thanks, JM

--
JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
25000 Besancon, France

June 22, 2020 1:25 PM, "Marcus Müller"  wrote:

> It gets even better:
> 
> We've launched a feature in 3.8.1.0 (and on master before that, as we do 
> with any feature that ends up in a maintenance release) that we hope 
> doesn't come back to bite us due to enabling unclean design. But, we 
> must build best practices so that it doesn't go unused, either, so:
> 
> Assuming you're using GNU Radio 3.8.1.0 (or later, once we release 
> something), you can make use of the "Python Snippets" in GRC.
> 
> Cheers,
> Marcus
> 
> On 18/06/2020 23.17, Marcus D. Leech wrote:
> 
>> On 06/18/2020 03:54 PM, jean-michel.fri...@femto-st.fr wrote:
>>> My approach:
>>> * build your grc chart from GNU Radio Companion and generate the .py file
>>> * edit the py file and import pygpio
>>> * play with the RPi4 GPIO in your python script.
>>> 
>>> See attached script, with a python server included in the Python script
>>> to control an RF switch from a GNU Octave TCP/IP client talking to the
>>> Python
>>> TCP/IP server.
>>> 
>>> I am presenting this approach to hardware control at
>>> http://jmfriedt.free.fr/sdra_radar.pdf
>>> 
>>> JM
>> 
>> If you use "Python Module" block, you can write a lot of
>> non-GnuRadio-esque python, import anything you want, etc, etc.  No editing
>> of the output python required, necessarily.
>> 
>>> --
>>> JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
>>> 25000 Besancon, France
>>> 
>>> June 18, 2020 9:40 PM, "Da Fy"  wrote:
>> 
>> Hi All, does anyone have an example of how to control GOIO lines on
>> the RPi4 from within a GRC
>> flowgraph. I’m guessing it’s an OOT module.
>> 
>> I need to generate a signal of a few 100Hz & control GPIO lines at
>> various points though the cycle.
>> 
>> Alternatively, I could generate the signal & lines with external
>> hardware & read them with
>> GnuRadio.
>> 
>> Tnx, Dave



Re: GPIO lines on RPi4

2020-06-22 Thread Albin Stigö
Seems like you already understand the limitations! Good luck with you
project!

--Albin

On Mon, Jun 22, 2020, 14:30 jean-michel.fri...@femto-st.fr <
jean-michel.fri...@femto-st.fr> wrote:

> The envisioned application is event driven: send a control word from a
> client,
> wait for the even to complete (e.g. move antenna to target position), start
> streaming data for a given amount of time, and when enough data is
> collected move
> to new position. Of course timing cannot be relied on with a non-real time
> multitasking
> operating system whose load is not predictable.
>
> I did use successfully Python Module to implement the server and tune the
> UHD parameters
> during the week end without editing the Python code (why the Python Module
> must be entered
> through the GRC Python editor and not externally for the updates not to be
> lost is still
> not yet understood). Will have a look at this new Python Snippet feature.
>
> Thanks, JM
>
> --
> JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
> 25000 Besancon, France
>
> June 22, 2020 2:05 PM, "Albin Stigö"  wrote:
>
> > It might be difficult to control GPIO with precise timing on raspberry
> pi depending on what you
> > want to do... A few hundred khz might be ok though. libgpiod is the new
> better Linux GPIO API.
> >
> > --Albin
> >
> > On Mon, Jun 22, 2020, 13:25 Marcus Müller  wrote:
> >
> >> It gets even better:
> >>
> >> We've launched a feature in 3.8.1.0 (and on master before that, as we do
> >> with any feature that ends up in a maintenance release) that we hope
> >> doesn't come back to bite us due to enabling unclean design. But, we
> >> must build best practices so that it doesn't go unused, either, so:
> >>
> >> Assuming you're using GNU Radio 3.8.1.0 (or later, once we release
> >> something), you can make use of the "Python Snippets" in GRC.
> >>
> >> Cheers,
> >> Marcus
> >>
> >> On 18/06/2020 23.17, Marcus D. Leech wrote:
> >>> On 06/18/2020 03:54 PM, jean-michel.fri...@femto-st.fr wrote:
>  My approach:
>  * build your grc chart from GNU Radio Companion and generate the .py
> file
>  * edit the py file and import pygpio
>  * play with the RPi4 GPIO in your python script.
> 
>  See attached script, with a python server included in the Python
> script
>  to control an RF switch from a GNU Octave TCP/IP client talking to the
>  Python
>  TCP/IP server.
> 
>  I am presenting this approach to hardware control at
>  http://jmfriedt.free.fr/sdra_radar.pdf
> 
>  JM
> >>> If you use "Python Module" block, you can write a lot of
> >>> non-GnuRadio-esque python, import anything you want, etc, etc. No
> editing
> >>> of the output python required, necessarily.
> >>>
> >>>
> 
>  --
>  JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
>  25000 Besancon, France
> 
>  June 18, 2020 9:40 PM, "Da Fy"  wrote:
> 
> > Hi All, does anyone have an example of how to control GOIO lines on
> > the RPi4 from within a GRC
> > flowgraph. I’m guessing it’s an OOT module.
> >
> > I need to generate a signal of a few 100Hz & control GPIO lines at
> > various points though the cycle.
> >
> > Alternatively, I could generate the signal & lines with external
> > hardware & read them with
> > GnuRadio.
> >
> > Tnx, Dave
> >>>
> >>>
>


Re: GPIO lines on RPi4

2020-06-22 Thread jean-michel.fri...@femto-st.fr
The envisioned application is event driven: send a control word from a client,
wait for the even to complete (e.g. move antenna to target position), start
streaming data for a given amount of time, and when enough data is collected 
move
to new position. Of course timing cannot be relied on with a non-real time 
multitasking
operating system whose load is not predictable.

I did use successfully Python Module to implement the server and tune the UHD 
parameters
during the week end without editing the Python code (why the Python Module must 
be entered
through the GRC Python editor and not externally for the updates not to be lost 
is still
not yet understood). Will have a look at this new Python Snippet feature.

Thanks, JM

--
JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
25000 Besancon, France

June 22, 2020 2:05 PM, "Albin Stigö"  wrote:

> It might be difficult to control GPIO with precise timing on raspberry pi 
> depending on what you
> want to do... A few hundred khz might be ok though. libgpiod is the new 
> better Linux GPIO API.
> 
> --Albin
> 
> On Mon, Jun 22, 2020, 13:25 Marcus Müller  wrote:
> 
>> It gets even better:
>> 
>> We've launched a feature in 3.8.1.0 (and on master before that, as we do
>> with any feature that ends up in a maintenance release) that we hope
>> doesn't come back to bite us due to enabling unclean design. But, we
>> must build best practices so that it doesn't go unused, either, so:
>> 
>> Assuming you're using GNU Radio 3.8.1.0 (or later, once we release
>> something), you can make use of the "Python Snippets" in GRC.
>> 
>> Cheers,
>> Marcus
>> 
>> On 18/06/2020 23.17, Marcus D. Leech wrote:
>>> On 06/18/2020 03:54 PM, jean-michel.fri...@femto-st.fr wrote:
 My approach:
 * build your grc chart from GNU Radio Companion and generate the .py file
 * edit the py file and import pygpio
 * play with the RPi4 GPIO in your python script.
 
 See attached script, with a python server included in the Python script
 to control an RF switch from a GNU Octave TCP/IP client talking to the
 Python
 TCP/IP server.
 
 I am presenting this approach to hardware control at
 http://jmfriedt.free.fr/sdra_radar.pdf
 
 JM
>>> If you use "Python Module" block, you can write a lot of
>>> non-GnuRadio-esque python, import anything you want, etc, etc. No editing
>>> of the output python required, necessarily.
>>> 
>>> 
 
 --
 JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
 25000 Besancon, France
 
 June 18, 2020 9:40 PM, "Da Fy"  wrote:
 
> Hi All, does anyone have an example of how to control GOIO lines on
> the RPi4 from within a GRC
> flowgraph. I’m guessing it’s an OOT module.
> 
> I need to generate a signal of a few 100Hz & control GPIO lines at
> various points though the cycle.
> 
> Alternatively, I could generate the signal & lines with external
> hardware & read them with
> GnuRadio.
> 
> Tnx, Dave
>>> 
>>>



Re: GPIO lines on RPi4

2020-06-22 Thread Albin Stigö
It might be difficult to control GPIO with precise timing on raspberry pi
depending on what you want to do... A few hundred khz might be ok though.
libgpiod is the new better Linux GPIO API.

--Albin

On Mon, Jun 22, 2020, 13:25 Marcus Müller  wrote:

> It gets even better:
>
> We've launched a feature in 3.8.1.0 (and on master before that, as we do
> with any feature that ends up in a maintenance release) that we hope
> doesn't come back to bite us due to enabling unclean design. But, we
> must build best practices so that it doesn't go unused, either, so:
>
> Assuming you're using GNU Radio 3.8.1.0 (or later, once we release
> something), you can make use of the "Python Snippets" in GRC.
>
> Cheers,
> Marcus
>
> On 18/06/2020 23.17, Marcus D. Leech wrote:
> > On 06/18/2020 03:54 PM, jean-michel.fri...@femto-st.fr wrote:
> >> My approach:
> >> * build your grc chart from GNU Radio Companion and generate the .py
> file
> >> * edit the py file and import pygpio
> >> * play with the RPi4 GPIO in your python script.
> >>
> >> See attached script, with a python server included in the Python script
> >> to control an RF switch from a GNU Octave TCP/IP client talking to the
> >> Python
> >> TCP/IP server.
> >>
> >> I am presenting this approach to hardware control at
> >> http://jmfriedt.free.fr/sdra_radar.pdf
> >>
> >> JM
> > If you use "Python Module" block, you can write a lot of
> > non-GnuRadio-esque python, import anything you want, etc, etc.  No
> editing
> >of the output python required, necessarily.
> >
> >
> >>
> >> --
> >> JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
> >> 25000 Besancon, France
> >>
> >> June 18, 2020 9:40 PM, "Da Fy"  wrote:
> >>
> >>> Hi All, does anyone have an example of how to control GOIO lines on
> >>> the RPi4 from within a GRC
> >>> flowgraph. I’m guessing it’s an OOT module.
> >>>
> >>> I need to generate a signal of a few 100Hz & control GPIO lines at
> >>> various points though the cycle.
> >>>
> >>> Alternatively, I could generate the signal & lines with external
> >>> hardware & read them with
> >>> GnuRadio.
> >>>
> >>> Tnx, Dave
> >
> >
>
>


Re: GPIO lines on RPi4

2020-06-22 Thread Marcus Müller

It gets even better:

We've launched a feature in 3.8.1.0 (and on master before that, as we do 
with any feature that ends up in a maintenance release) that we hope 
doesn't come back to bite us due to enabling unclean design. But, we 
must build best practices so that it doesn't go unused, either, so:


Assuming you're using GNU Radio 3.8.1.0 (or later, once we release 
something), you can make use of the "Python Snippets" in GRC.


Cheers,
Marcus

On 18/06/2020 23.17, Marcus D. Leech wrote:

On 06/18/2020 03:54 PM, jean-michel.fri...@femto-st.fr wrote:

My approach:
* build your grc chart from GNU Radio Companion and generate the .py file
* edit the py file and import pygpio
* play with the RPi4 GPIO in your python script.

See attached script, with a python server included in the Python script
to control an RF switch from a GNU Octave TCP/IP client talking to the 
Python

TCP/IP server.

I am presenting this approach to hardware control at
http://jmfriedt.free.fr/sdra_radar.pdf

JM
If you use "Python Module" block, you can write a lot of 
non-GnuRadio-esque python, import anything you want, etc, etc.  No editing

   of the output python required, necessarily.




--
JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
25000 Besancon, France

June 18, 2020 9:40 PM, "Da Fy"  wrote:

Hi All, does anyone have an example of how to control GOIO lines on 
the RPi4 from within a GRC

flowgraph. I’m guessing it’s an OOT module.

I need to generate a signal of a few 100Hz & control GPIO lines at 
various points though the cycle.


Alternatively, I could generate the signal & lines with external 
hardware & read them with

GnuRadio.

Tnx, Dave







smime.p7s
Description: S/MIME Cryptographic Signature


Re: GPIO lines on RPi4

2020-06-18 Thread Marcus D. Leech

On 06/18/2020 03:54 PM, jean-michel.fri...@femto-st.fr wrote:

My approach:
* build your grc chart from GNU Radio Companion and generate the .py file
* edit the py file and import pygpio
* play with the RPi4 GPIO in your python script.

See attached script, with a python server included in the Python script
to control an RF switch from a GNU Octave TCP/IP client talking to the Python
TCP/IP server.

I am presenting this approach to hardware control at
http://jmfriedt.free.fr/sdra_radar.pdf

JM
If you use "Python Module" block, you can write a lot of 
non-GnuRadio-esque python, import anything you want, etc, etc.  No editing

  of the output python required, necessarily.




--
JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
25000 Besancon, France

June 18, 2020 9:40 PM, "Da Fy"  wrote:


Hi All, does anyone have an example of how to control GOIO lines on the RPi4 
from within a GRC
flowgraph. I’m guessing it’s an OOT module.

I need to generate a signal of a few 100Hz & control GPIO lines at various 
points though the cycle.

Alternatively, I could generate the signal & lines with external hardware & 
read them with
GnuRadio.

Tnx, Dave





Re: GPIO lines on RPi4

2020-06-18 Thread jean-michel.fri...@femto-st.fr
My approach:
* build your grc chart from GNU Radio Companion and generate the .py file
* edit the py file and import pygpio
* play with the RPi4 GPIO in your python script.

See attached script, with a python server included in the Python script
to control an RF switch from a GNU Octave TCP/IP client talking to the Python
TCP/IP server.

I am presenting this approach to hardware control at
http://jmfriedt.free.fr/sdra_radar.pdf

JM


--
JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
25000 Besancon, France

June 18, 2020 9:40 PM, "Da Fy"  wrote:

> Hi All, does anyone have an example of how to control GOIO lines on the RPi4 
> from within a GRC
> flowgraph. I’m guessing it’s an OOT module.
> 
> I need to generate a signal of a few 100Hz & control GPIO lines at various 
> points though the cycle.
> 
> Alternatively, I could generate the signal & lines with external hardware & 
> read them with
> GnuRadio.
> 
> Tnx, Dave


s.py
Description: Binary data