HID and FUNcube

I've just had an email saying my FUNcube pro plus has been sent. So,
fingers crossed, it may come in the next day or two.

With that in mind I've been looking again at the various existing software
I can use to start experiments. One question I'd like to ask in case
someone already has experience:

http://gitorious.org/fcdcontrol

has a fork to

http://gitorious.org/~csete/fcdcontr...ontrol-proplus

to both drive the pro plus version *and* do it on an RPi.

What isn't immediately clear to me is if the second above will compile and
run on an x86 machine, or if I'd need to tweak my own version of the first
to drive the pro plus. I'll investigate. But if anyone already has
experience with it or knows, advice would be welcome!

I'm looking for low-level 'direct' ways to control the pro plus as I'm
intending to use it for purposes like a spectrum analyser or to model FM
VHF tuners. But I do also intend to try out things like

http://www.oz9aec.net/index.php/func...fcd-controller

(version 4.1)

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
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Audio Misc http://www.audiomisc.co.uk/index.html

On Tue, 29 Jan 2013 16:18:24 +0000, Jim Lesurf wrote:

What isn't immediately clear to me is if the second above will compile
and run on an x86 machine, or if I'd need to tweak my own version of the
first to drive the pro plus. I'll investigate. But if anyone already has
experience with it or knows, advice would be welcome!

My (slight) experience in this area says that if it will compile under gcc
on any hardware, it will also compile under a similar version of gcc on
other hardware.

My favourite command line editor is Microemacs 4.00, which I've used on
Linux ever since I started using it (and before that I used it on
OS-9/68000 v2.4, various Unices, DOS and W95). So, as soon as I got an RPi
and found out how horrid nano is and how much worse the RPi vi is than
the RedHat vim, of course I ported Microemacs to the RPi. In summary:

- Microemacs compiled immediately but wouldn't link because the termcap
library and headers were missing.

- I installed the GNU termcap source, which compiled and installed
immediately. Microemacs now linked correctly, but complained about
missing termcap capabilities in the xterm terminal definition.

- I'd ported my termcap file from Fedora 16. This uses the 'tc' capability
to link termcap definition fragments but the GNU termcap doesn't
support the 'tc' capability (big surprise: its forever since I found
a termcap that didn't). So, I edited /etc/termcap to get rid of 'tc'
usage in the definitions I care about.

- Microemacs immediately started to work how I expect it to work.

FWIW 1: I initially ported Microemacs to Linux way back in the RedHat 6.2
days and hadn't needed to compile it for a very long time. IIRC the
version currently running on my F17 box is that self-same binary.

FWIW 2: a few years back I wrote a DOS command line utility to help a
friend. I initially wrote it using gcc under Linux and then moved it to a
W95 box with the djgpp port of (an older version of) gcc installed. The
program compiled and ran with no problems whatever. I think my friend
uses it under XP and, if it gave him any gyp, he hasn't told me about it.
This was moderately impressive since the program is a rather fancy file
renaming tool that does things that are hard in a bash shell and near
impossible with the DOS shell. Its purpose is to build an archive of
files that always arrive with the same name, so among other things it can
build a new file name that combines fragments of the original name,
literals and parts of the current date&time and then rename the file to
the result. IOW, its using the (potentially) less portable parts of the
program's OS interface.


--
[email protected] | Martin Gregorie
gregorie. | Essex, UK
org |

On 29 Jan, wrote:
I've just had an email saying my FUNcube pro plus has been sent. So,
fingers crossed, it may come in the next day or two.

Pleased to say that FUNcube (fcpp) has arrived and I have it working. Work
to still do, but I've already managed to get a basic spectrum of part of
the DTTV band using it. :-)

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

I've now done a rough scan using the fcpp as a test.

The results are at http://jcgl.orpheusweb.co.uk/temp/quicktest.png


I did these scans by the process of first starting an 'arecord' saving
the IQ values into a file. Then leaving that running whilst I clicked on
the 1 MHz digit about once a second, to increment the tuned frequency.
Having spent a while doing this (boring!) process I quit saving the
recording and analysed the results

I scanned a portion of the UHF band which is used by one of our local TV
TXs (Durris).

I then repeated the process, but for a shorter time, with nothing connected
to the RF input of the fcpp.

On the graph the red/blue lines show the results when looking at Durris.
The green/violet ones with no input.

I processed the IQ values to remove the dc offsets, then did rms values for
each 100 ms of the recorded results.

Pleased to say that the Durris patterns look quite similar to spectra I got
using an HP8591E spectrum analyser a few months ago. Then the central TV
multiplex was showing about -10dBmV (75 Ohm) with a resolution bandwidth of
300 kHz which is fairly close to the 192 kHz of the fcpp. So I now have
some idea of the fcpp sensitivity and gain at these frequencies.

I used the same UHF antenna and a small preamp as previously for the
HP8591E results.

The 'no input' is clearly giving a lower level than in between the muxes
for the Durris scan. I'm not sure how much is noise from the small preamp
and how much is sky/environment noise. But the results look promising.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Jim Lesurf wrote:

The 'no input' is clearly giving a lower level than in between the muxes
for the Durris scan. I'm not sure how much is noise from the small preamp
and how much is sky/environment noise. But the results look promising.

Speaking very loosely, I'd expect the noise to come up like that when a
preamp was connected, whether or not the preamp had an input.

Bill

In article , Bill Wright
wrote:
Jim Lesurf wrote:

The 'no input' is clearly giving a lower level than in between the
muxes for the Durris scan. I'm not sure how much is noise from the
small preamp and how much is sky/environment noise. But the results
look promising.

Speaking very loosely, I'd expect the noise to come up like that when a
preamp was connected, whether or not the preamp had an input.

Yes. I'm not surprised by the increase. Indeed, I was pleased to see it
because it implies the LNA inside the FUNcube *is* low-noise. But I'm not
yet clear how much is due to the preamp (which claims a low noise figure)
or 'sky noise'. One of the things I hope to determine when I get a chance.
However before that I want to sort out automating the scans and processing
the output.

Looks good for about 150 quid, though. Already comparable with the HP
analyser I borrowed!

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Jim Lesurf wrote:
In article , Bill Wright
wrote:
Jim Lesurf wrote:

The 'no input' is clearly giving a lower level than in between the
muxes for the Durris scan. I'm not sure how much is noise from the
small preamp and how much is sky/environment noise. But the results
look promising.

Speaking very loosely, I'd expect the noise to come up like that when a
preamp was connected, whether or not the preamp had an input.

Yes. I'm not surprised by the increase. Indeed, I was pleased to see it
because it implies the LNA inside the FUNcube *is* low-noise. But I'm not
yet clear how much is due to the preamp (which claims a low noise figure)
or 'sky noise'. One of the things I hope to determine when I get a chance.

I suppose that means dragging your weary arse into the loft?

Bill

In article , Bill Wright
wrote:
Jim Lesurf wrote:


Yes. I'm not surprised by the increase. Indeed, I was pleased to see
it because it implies the LNA inside the FUNcube *is* low-noise. But
I'm not yet clear how much is due to the preamp (which claims a low
noise figure) or 'sky noise'. One of the things I hope to determine
when I get a chance.

I suppose that means dragging your weary arse into the loft?

Happily, no! :-) The preamp in question is in the 'dining room'[1].
However I want to automate doing the scans before doing more tests. Will
save time and produce better-controlled results.

The initial 'spectra' were made by the tedious process of clicking an icon
to increment the tuned frequency about once a second.

Once I can get a half-decent scanning program working I'll try measurements
with and without the preamp. And also do similar tests with other antenna
systems in the house.

FWIW I may also ask my old research group if I can re-borrow the HP sig gen
they loaned to me a few months ago. This will help me calibrate the FUNcube
and do some tests with an eye to developing a stereo FM 'radio' using it.

Slainte,

Jim

[1] So named because that was its primary use. But gradually it also became
where I have my main computers, and do measurements, soldering, etc.

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On Sun, 03 Feb 2013 09:39:11 +0000 (GMT)
Jim Lesurf wrote:

[1] So named because that was its primary use. But gradually it also became
where I have my main computers, and do measurements, soldering, etc.

How strange. I've got a room just like that

--
W J G

Pleased to say I've made some progress with making a wideband 'swept
spectrum analyser' using the fcpp. Still bugs to sort out but a preliminary
result is shown at

http://jcgl.orpheusweb.co.uk/temp/skanna.png

for anyone who is interested. This shows the output from a domestic antenna
system pointed at the Durris DTTV TX about 75 km away. The signals from
Angus (only 25km) are at the high frequency end of the spectrum, but the
antenna isn't pointed in that direction.

dB scale as yet uncalibrated for the 0dB level/ref. Made, dwelling at each
tuned 'bin' (frequency) for 50 ms.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html