If there are other USB oscilloscope options worth looking at
please post. I don't specifically need RF performance, but if
it's available it's worth a look.
bob prohaska wrote:
If there are other USB oscilloscope options worth looking at
please post. I don't specifically need RF performance, but if
it's available it's worth a look.
look at SDR software defined radio. Especially receivers are ~20,- US$ range
Has anybody used a USB sound capture device for an audio frequency oscilloscope on a Raspberry Pi? xoscope is available using apt,
but I can't find any reference to what sound devices, if any, it
can use over USB.
If there are other USB oscilloscope options worth looking at
please post. I don't specifically need RF performance, but if
it's available it's worth a look.
Thanks for reading,
bob prohaska
Deloptes <deloptes@gmail.com> wrote:
bob prohaska wrote:
If there are other USB oscilloscope options worth looking at
please post. I don't specifically need RF performance, but if
it's available it's worth a look.
Often for oscilloscope purposes you're interested in DC, which is outside
the range of this hardware. Soundcards may go that low, or maybe it can if you remove a series capacitor.
It is worth understanding what frequency range you're interested in. Soundcards are typically 20Hz-20kHz.
SDR often has a limited bandwidth and doesn't go below ~30MHz.
Has anybody used a USB sound capture device for an audio frequency oscilloscope on a Raspberry Pi? xoscope is available using apt, but I
can't find any reference to what sound devices, if any, it can use over
USB.
If there are other USB oscilloscope options worth looking at please
post. I don't specifically need RF performance, but if it's available
it's worth a look.
Theo wrote:
It is worth understanding what frequency range you're interested in. Soundcards are typically 20Hz-20kHz.
SDR often has a limited bandwidth and doesn't go below ~30MHz.
Ah, sorry I understood the opposite - I missed or misunderstood "I
don't specifically need RF performance" as if OP was asking for RF explicitely :)
I know only the PicoScope from the Automotive angle, but could be
there are cheaper products that work with linux.
Has anybody used a USB sound capture device for an audio frequency oscilloscope on a Raspberry Pi? xoscope is available using apt,
but I can't find any reference to what sound devices, if any, it
can use over USB.
Of course at this point you've got a significant amount of front-end circuitry for your "simple" sound card oscilloscope. For a data logging application that might be quite reasonable, but for basic
troubleshooting maybe it would be easier to just buy an old CRO (Cathode
Ray Oscilloscope), which has the added benefit of working outside the
audio frequency range.
I suspect you'll get better suggestions if you can outline what you are trying to do.
For instance, are you trying to get analogue output from digital
recordings or do you want to digitise audio from a mic or turntable?
What pert of the system (analogue or digital) do you need to trouble-
shoot?
On Wed, 21 Apr 2021 20:22:27 +0200
Deloptes <deloptes@gmail.com> wrote:
Theo wrote:
It is worth understanding what frequency range you're interested in.
Soundcards are typically 20Hz-20kHz.
SDR often has a limited bandwidth and doesn't go below ~30MHz.
Ah, sorry I understood the opposite - I missed or misunderstood "I
don't specifically need RF performance" as if OP was asking for RF
explicitely :)
I know only the PicoScope from the Automotive angle, but could be
there are cheaper products that work with linux.
Hantek is the name, or at least one of the names, many people rebadge
them. There is openhantek6022 which works for the cheapest scope.
It's OK for DC and audio, which is all I need these days. If I have frequencies a bit higher to deal with, I haul out my ancient Tek 465B,
which weighs about fifty times as much as the Hantek device.
bob prohaska <bp@www.zefox.net> wrote:
Has anybody used a USB sound capture device for an audio frequency
oscilloscope on a Raspberry Pi? xoscope is available using apt,
but I can't find any reference to what sound devices, if any, it
can use over USB.
Xoscope's webpage says it supports ALSA as an input source, so as
long as a USB audio adapter is working with ALSA (the cheap Chinese
ones seem to do so without issues) it should be fine.
It will have a series capacitor to block DC. You'll need to either
remove this (might be difficult if it's a small indistinct-looking
SMD part) or use a chopper circuit like this if you want to measure
DC signals:
http://lea.hamradio.si/~s57uuu/scdsp/CheapChop/cheapchop.htm
For more sensible input impedence (so the behaviour of the circuit
doesn't change when you probe it), the buffer circuit shown at the
xoscope homepage would also be recommended: http://xoscope.sourceforge.net/hardware/hardware.html
Of course at this point you've got a significant amount of
front-end circuitry for your "simple" sound card oscilloscope. For
a data logging application that might be quite reasonable, but for
basic troubleshooting maybe it would be easier to just buy an old
CRO (Cathode Ray Oscilloscope), which has the added benefit of
working outside the audio frequency range.
If there are other USB oscilloscope options worth looking at
please post. I don't specifically need RF performance, but if
it's available it's worth a look.
On Wed, 21 Apr 2021 03:05:36 -0000 (UTC)
bob prohaska <bp@www.zefox.net> wrote:
If there are other USB oscilloscope options worth looking at
please post. I don't specifically need RF performance, but if
it's available it's worth a look.
A search for raspberry pi DSO revealed a range of devices called
bitscope which (if as good as advertised) look like handy devices, probably >overkill for what you want but it would have cleared several feet of bench >space in my 1980s labs.
Computer Nerd Kev <not@telling.you.invalid> wrote:
bob prohaska <bp@www.zefox.net> wrote:Ok, that's a good hint. I'm looking at something like: >https://www.amazon.com/DIGITNOW-Capture-Grabber-Cassette-Converter/dp/B079CBGDST/ref=pd_rhf_dp_p_img_2?_encoding=UTF8&psc=1&refRID=YV3EVDFX4FWZF58TY2CW
Has anybody used a USB sound capture device for an audio frequency
oscilloscope on a Raspberry Pi? xoscope is available using apt,
but I can't find any reference to what sound devices, if any, it
can use over USB.
Xoscope's webpage says it supports ALSA as an input source, so as
long as a USB audio adapter is working with ALSA (the cheap Chinese
ones seem to do so without issues) it should be fine.
There are reviews saying it works with Raspberry Pi, so maybe it'll work
with xoscope. It doesn't have to be good, just good enough to catch
sags and spikes on a timescale of milliseconds.
Joe <joe@jretrading.com> wrote:
On Wed, 21 Apr 2021 20:22:27 +0200
Deloptes <deloptes@gmail.com> wrote:
Theo wrote:
It is worth understanding what frequency range you're interested
in. Soundcards are typically 20Hz-20kHz.
SDR often has a limited bandwidth and doesn't go below ~30MHz.
Ah, sorry I understood the opposite - I missed or misunderstood "I
don't specifically need RF performance" as if OP was asking for RF
explicitely :)
I know only the PicoScope from the Automotive angle, but could be
there are cheaper products that work with linux.
Hantek is the name, or at least one of the names, many people
rebadge them. There is openhantek6022 which works for the cheapest
scope.
It's OK for DC and audio, which is all I need these days. If I have frequencies a bit higher to deal with, I haul out my ancient Tek
465B, which weighs about fifty times as much as the Hantek device.
Hantek seems to be Windows-oriented, I have great respect for
Tektronix, but analog scopes are no help with transients absent a
Polaroid camera and a stable trigger pulse.
On Thu, 22 Apr 2021 07:26:28 +0100
Ahem A Rivet's Shot <steveo@eircom.net> wrote:
A search for raspberry pi DSO revealed a range of devices called
bitscope which (if as good as advertised) look like handy devices,
probably overkill for what you want but it would have cleared several
feet of bench space in my 1980s labs.
Bitscope are expensive for what they are, and not actually very good (you won't see transients at all). I get *far* better results with an ancient Scopex.
On 21/04/2021 17:30, Theo wrote:
Deloptes <deloptes@gmail.com> wrote:
bob prohaska wrote:
If there are other USB oscilloscope options worth looking at
please post. I don't specifically need RF performance, but if
it's available it's worth a look.
Often for oscilloscope purposes you're interested in DC, which is outside
the range of this hardware. Soundcards may go that low, or maybe it
can if
you remove a series capacitor.
There is also this portable kit for £28.86 from Amazon. Could be junk,
not built mine yet (too much trigger happy shopping, it's sat on a shelf).
Kuman JYE DSO Shell Oscilloscope DIY Kit with Open Source 2.4 inch color
TFT LCD+ Shell + DIY Parts + Probe 15001K (SMD pre-soldered) https://www.amazon.co.uk/gp/product/B01MY7HAFG
Has anybody used a USB sound capture device for an audio frequency oscilloscope on a Raspberry Pi? xoscope is available using apt,
but I can't find any reference to what sound devices, if any, it
can use over USB.
If there are other USB oscilloscope options worth looking at
please post. I don't specifically need RF performance, but if
it's available it's worth a look.
Thanks for reading,
bob prohaska
Joe <joe@jretrading.com> wrote:
On Wed, 21 Apr 2021 20:22:27 +0200 Deloptes <deloptes@gmail.com> wrote:Hantek seems to be Windows-oriented, I have great respect for Tektronix,
Theo wrote:
It is worth understanding what frequency range you're interested in.
Soundcards are typically 20Hz-20kHz.
SDR often has a limited bandwidth and doesn't go below ~30MHz.
Ah, sorry I understood the opposite - I missed or misunderstood "I
don't specifically need RF performance" as if OP was asking for RF
explicitely :)
I know only the PicoScope from the Automotive angle, but could be
there are cheaper products that work with linux.
Hantek is the name, or at least one of the names, many people rebadge
them. There is openhantek6022 which works for the cheapest scope.
It's OK for DC and audio, which is all I need these days. If I have
frequencies a bit higher to deal with, I haul out my ancient Tek 465B,
which weighs about fifty times as much as the Hantek device.
but analog scopes are no help with transients absent a Polaroid camera
and a stable trigger pulse.
Please forgive my ignorance on the topic, but would it be possible to
use another PI with 'duino type device? Seems the duino would do the
sampling and relay the results to the other PI.
The motivating problem is monitoring power supply voltage on a Raspberry
Pi4 during boot and disk spin-up. I'd like to see the voltage rise, sag >during boot and spin-up and then stabilize. Depth and duration of the
sag would be the most essential observation.
On Wed, 21 Apr 2021 20:22:27 +0200 Deloptes <deloptes@gmail.com> wrote:
Theo wrote:
It is worth understanding what frequency range you're interested in. Soundcards are typically 20Hz-20kHz. SDR often has a limited bandwidth and doesn't go below ~30MHz.
Ah, sorry I understood the opposite - I missed or misunderstood "I don't specifically need RF performance" as if OP was asking for RF explicitely
:)
I know only the PicoScope from the Automotive angle, but could be there
are cheaper products that work with linux.
Hantek is the name, or at least one of the names, many people rebadge them. There is openhantek6022 which works for the cheapest scope.
It's OK for DC and audio, which is all I need these days. If I have frequencies a bit higher to deal with, I haul out my ancient Tek 465B,
which weighs about fifty times as much as the Hantek device.
That's why I mention openhantex6022. It's specific to the 6022 but it's native Linux, later ported to Windows. I never found the Hantek supplied Windows software to be much good at triggering.
Please forgive my ignorance on the topic, but would it be possible to
use another PI with 'duino type device? Seems the duino would do the
sampling and relay the results to the other PI.
Joe <joe@jretrading.com> wrote:
That's why I mention openhantex6022. It's specific to the 6022 but
it's native Linux, later ported to Windows. I never found the
Hantek supplied Windows software to be much good at triggering.
I'm impressed. Downloaded the tarball and had it built in a few
minutes on an 8GB Pi4 running raspberrypi 5.10.17-v7l+ #1403 SMP
Mon Feb 22 11:33:35 GMT 2021. Run without installing it reports:
bob@raspberrypi:~/OpenHantek-openhantek-e7e0c7b $ ./build/openhantek/OpenHantek libEGL warning: DRI2: failed to
authenticate qt5ct: using qt5ct plugin
QEGLPlatformContext: Failed to create context: 3009
libpng warning: iCCP: known incorrect sRGB profile
BlueALSA detected - Disabling audio sandbox
libEGL warning: DRI2: failed to authenticate
Not sure how important the errors are, I didn't install, nor mess
with the devd permissions. It doesn't seem to recognize demo mode,
has the flag option changed? I'd like to see the demo mode before
running out and buying hardware.
Are there any other tests worth doing before buying some hardware?
Thanks for writing!
bob prohaska
Joe <joe@jretrading.com> wrote:
That's why I mention openhantex6022. It's specific to the 6022 but
it's native Linux, later ported to Windows. I never found the
Hantek supplied Windows software to be much good at triggering.
I'm impressed. Downloaded the tarball and had it built in a few
minutes on an 8GB Pi4 running raspberrypi 5.10.17-v7l+ #1403 SMP
Mon Feb 22 11:33:35 GMT 2021. Run without installing it reports:
bob@raspberrypi:~/OpenHantek-openhantek-e7e0c7b $ ./build/openhantek/OpenHantek libEGL warning: DRI2: failed to
authenticate qt5ct: using qt5ct plugin
QEGLPlatformContext: Failed to create context: 3009
libpng warning: iCCP: known incorrect sRGB profile
BlueALSA detected - Disabling audio sandbox
libEGL warning: DRI2: failed to authenticate
Not sure how important the errors are, I didn't install, nor mess
with the devd permissions. It doesn't seem to recognize demo mode,
has the flag option changed? I'd like to see the demo mode before
running out and buying hardware.
Are there any other tests worth doing before buying some hardware?
Computer Nerd Kev <not@telling.you.invalid> wrote:
bob prohaska <bp@www.zefox.net> wrote:Ok, that's a good hint. I'm looking at something like: https://www.amazon.com/DIGITNOW-Capture-Grabber-Cassette-Converter/dp/B079CBGDST/ref=pd_rhf_dp_p_img_2?_encoding=UTF8&psc=1&refRID=YV3EVDFX4FWZF58TY2CW
Has anybody used a USB sound capture device for an audio frequency
oscilloscope on a Raspberry Pi? xoscope is available using apt,
but I can't find any reference to what sound devices, if any, it
can use over USB.
Xoscope's webpage says it supports ALSA as an input source, so as
long as a USB audio adapter is working with ALSA (the cheap Chinese
ones seem to do so without issues) it should be fine.
There are reviews saying it works with Raspberry Pi, so maybe it'll work
with xoscope.
Of course at this point you've got a significant amount of
front-end circuitry for your "simple" sound card oscilloscope. For
a data logging application that might be quite reasonable, but for
basic troubleshooting maybe it would be easier to just buy an old
CRO (Cathode Ray Oscilloscope), which has the added benefit of
working outside the audio frequency range.
I'm experienced with analog 'scopes and don't want one. They aren't
useful for catching one-off transient events, which is what I'm looking
for. Something with a stop trigger is essential. A freestanding DSO
would be nice, but I won't use it enough to justify the cost and storage.
Has anybody used a USB sound capture device for an audio frequency oscilloscope on a Raspberry Pi? xoscope is available using apt,
but I can't find any reference to what sound devices, if any, it
can use over USB.
If there are other USB oscilloscope options worth looking at
please post. I don't specifically need RF performance, but if
it's available it's worth a look.
bob prohaska <bp@www.zefox.net> wrote:
Computer Nerd Kev <not@telling.you.invalid> wrote:
bob prohaska <bp@www.zefox.net> wrote:Ok, that's a good hint. I'm looking at something like:
Has anybody used a USB sound capture device for an audio frequency
oscilloscope on a Raspberry Pi? xoscope is available using apt,
but I can't find any reference to what sound devices, if any, it
can use over USB.
Xoscope's webpage says it supports ALSA as an input source, so as
long as a USB audio adapter is working with ALSA (the cheap Chinese
ones seem to do so without issues) it should be fine.
https://www.amazon.com/DIGITNOW-Capture-Grabber-Cassette-Converter/dp/B079CBGDST/ref=pd_rhf_dp_p_img_2?_encoding=UTF8&psc=1&refRID=YV3EVDFX4FWZF58TY2CW
There are reviews saying it works with Raspberry Pi, so maybe it'll work
with xoscope.
Xoscope just listens in on the audio stream, so if other ALSA audio
programs work, it will too.
Computer Nerd Kev <not@telling.you.invalid> wrote:
bob prohaska <bp@www.zefox.net> wrote:
Computer Nerd Kev <not@telling.you.invalid> wrote:
bob prohaska <bp@www.zefox.net> wrote:Ok, that's a good hint. I'm looking at something like:
Has anybody used a USB sound capture device for an audio frequency
oscilloscope on a Raspberry Pi? xoscope is available using apt,
but I can't find any reference to what sound devices, if any, it
can use over USB.
Xoscope's webpage says it supports ALSA as an input source, so as
long as a USB audio adapter is working with ALSA (the cheap Chinese
ones seem to do so without issues) it should be fine.
https://www.amazon.com/DIGITNOW-Capture-Grabber-Cassette-Converter/dp/B079CBGDST/ref=pd_rhf_dp_p_img_2?_encoding=UTF8&psc=1&refRID=YV3EVDFX4FWZF58TY2CW
There are reviews saying it works with Raspberry Pi, so maybe it'll work >>> with xoscope.
Xoscope just listens in on the audio stream, so if other ALSA audio
programs work, it will too.
Just got the DIGITNOW audio capture device. Audacity finds it without
trouble and displays AC hum on the VU bargraph, so I'm pretty sure
the hardware works. Dmesg reports
[2795922.290892] hid-generic 0003:2034:0105.000A: input,hidraw3: USB HID v1.00 Device [Generic USB Microphone] on usb-0000:01:00.0-1.4/input2
and lsusb -t reports
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 5000M
|__ Port 1: Dev 2, If 0, Class=Mass Storage, Driver=uas, 5000M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/1p, 480M
|__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 3: Dev 3, If 0, Class=Hub, Driver=hub/3p, 12M
|__ Port 1: Dev 5, If 0, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 1: Dev 5, If 1, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 2: Dev 6, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M
|__ Port 4: Dev 9, If 1, Class=Audio, Driver=snd-usb-audio, 12M
|__ Port 4: Dev 9, If 2, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 4: Dev 9, If 0, Class=Audio, Driver=snd-usb-audio, 12M
The device file corresponding to the sound capture device is /dev/hidraw3
However, xoscope looks for signal at /dev/comedi0, which isn't created. There's a dialog box which seems to invite device selection, but the
only choices are NONE and COMEDI.
If I try something like
sudo xoscope hidraw3
xoscope runs but says it can't read hidraw3.
It looks as if I'm either bungling the commandline syntax or the device filename.
Or, maybe some intermediate software is required. Comedi manpages are present, but
there don't seem to be any related executables.
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