Driver to drive?

[josephkk]

On Fri, 8 Mar 2013 16:59:48 -0800 (PST), George Herold
<gherold@teachspin.com> wrote:

On Mar 7, 9:26 pm, josephkk <joseph_barr...@sbcglobal.net> wrote:
On Wed, 06 Mar 2013 07:24:48 -0800, Joerg <inva...@invalid.invalid> wrote:
josephkk wrote:
On Sat, 02 Mar 2013 12:37:10 -0800, Joerg <inva...@invalid.invalid> wrote:

Hi Folks,

Long story short, none of the DDS modules I've found so far has the
ability to be sweeped or FM-modulated. This one has a signal input
terminal block "SIN" but I received a response from the manufacturer
that it connects to nowhere, it has no function:

http://imall.iteadstudio.com/tools-and-equipment/im120723003.html

What I need in my case is DC-100Hz of sweep or FM bandwidth. Operating
frequency under 10kHz and sweep range up to 2kHz. Of course I can whip
up an analog solution but it won't be as precise and most of all not
really programmable.

Is there anything better? Cost is not a big issue but should be somewhat
small and a display would be nice.

So use the Armstrong method.

What, erythropoietin? Some kind of growth hormone?



See:

http://en.wikipedia.org/wiki/Edwin_Howard_Armstrong


http://en.wikipedia.org/wiki/Armstrong_phase_modulator

Cool, I've seen this phasor diagram that shows FM is just 90 deg phase
shifted AM. (but only at low amplitude) I never knew how to make it
work, 'in practice'.

George H.

- Hide quoted text -

- Show quoted text -

The best way to learn is to just build one and play with it. It would be
fun to work with you if you want to explore this. I haven't had the
chance to actually build one, but i guessed the principle while still a
teen.

?-)

 

[Nico Coesel]

josephkk <joseph_barrett@sbcglobal.net> wrote:

On Fri, 08 Mar 2013 20:50:25 GMT, nico@puntnl.niks (Nico Coesel) wrote:

josephkk <joseph_barrett@sbcglobal.net> wrote:

On Mon, 04 Mar 2013 16:42:08 -0500, Spehro Pefhany
speffSNIP@interlogDOTyou.knowwhat> wrote:

On Mon, 04 Mar 2013 06:54:32 -0800, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

I made some crude measurements on a 120MHz STM32F2, emulated =
floating
point and gcc:

Double Precision:
0.415us / 49.852 cycles /multiply
0.378us / 45.403 cycles /add
2.414us / 289.702 cycles /divide

Single Precision:
0.194us / 23.350 cycles /multiply
0.250us / 30.052 cycles /add
0.610us / 73.202 cycles / divide

Pretty respectable I thought.

Yes, but not transcendental calcs.=3D20

As compared to 1 cycle for add/sub/shift/mul on an ARM.

STM32F2 is an ARM Cortex M3.=3D20

There's no reason to use any floats in a DDS sinewave generator.

No, but it might make calculating the frequencies during a sweep a bit
easier.=3D20

I can even do that in fixed point. Select a reference frequency, say =
100
Hz, then scale for frequency at beginning of sweep, and sweep step size

Ofcourse but with floating point its a total no brainer so faster to
develop. In the end floating point is automatic fixed point without
having to think about where to put the decimal point for maximum
accuracy.

I understand where you are coming from. But the nature of this
application, as stated, is inherently fixed point with an obvious radix
placement. Why put up with FP overhead when you don't need to.

If the overhead is not in the way then why bother trying to 'improve'
something which doesn't need improving? I'd rather spend my time on
adding features which are actually useful to the customer. New
technology brings new solutions to old problems.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------

 

[Jeff Liebermann]

On Sat, 9 Mar 2013 21:14:09 -0500, "Martin Riddle"
<martin_rid@verizon.net> wrote:

The Color stability in the printed images is very good.
I have a print that is over a year old and still looks fantastic.
It was from a 2025 or something like that, the refils are $80 for each
CMYK and Black.

The CP2025 is a tolerable color laserjet printer. I've fixed a few
and found them somewhat tricky due to flimsy internal construction.
They didn't seem to be very solidly built and tended to rattle quite a
bit when running.

The CP2025 will deliver about 3,000 color pages, for about
$28/cartridge on eBay at about 4 cents per page. At $80/ea, you're
overpaying.

I have an HP 2500n in the office and an HP 2600n at home. The 2500n
like to do weird things, like vaporize the bottom 1/4th of the page,
or produce odd colors. The 2600n has this problem:
<http://www.reeves-hall.net/tech-gadgets/fixing-washed-out-colour-on-hp-color-laserjet-2605/>
which I've been too lazy to fix. The most common problem with the
CP2025 so far, are caused by dirty connections to a toner cart that
caused a bright magenta strip across the page. Wipe off the crud from
the contacts occasionally.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Robert Baer]

John Larkin wrote:

On Sat, 9 Mar 2013 16:27:24 -0600, "Tim Williams"<tmoranwms@charter.net> wrote:

Since the topic comes up here from time to time, I just thought I'd brag a
little.

I've had a Canon Pixma iP6000D for years.

- Full color
- Photo quality prints
- Refillable ink cartridges (but I'm lazy, so I buy new anyway)
- Two sided (duplex) printing (slow, but it works)
- Allows printing with "low ink" warning, in fact, you can print until it
says "okay, now you're screwed, change the ink all damned ready!"

In the last two years, I haven't had much need for it, so it's been
sitting on its table, inactive. Plugged in but turned off. Never heard
it self-cleaning or anything, I'm quite sure it's "off-off", standby only.

Last week I needed a document, so I turned it on. After this long, I'd
expect it needs at least a deep clean. But for the hell of it, I printed
a test page.

Just a few jets were sticky, not even clogged.

The test image was actually quite passable, just not up to my standards.
So I gave it a single, basic cleaning. Nearly perfect test page after
that. Good to go.

With all the P&M people do about printers, why would they buy anything
besides this and a laser?

Of course, I doubt these machines are manufactured anymore, but used units
should be as cheap as a new POS-1 printer.

Tim

I have a few Laserjet CP1525's, which are great color laser printers if you
don't print a lot. The toner price is silly for quantity printing. They seem to
be perfectly reliable, but they do whine... they clean or calibrate themselves
at random, and it's pretty dramatic.

We have a huge Sharp digital copier at work, all networked. It works as a very
nice, very fast, B-size printer and we buy toner by the pound. It will feed and
scan stacks of paper into PDFs and dump that onto a server. Very cool.

In the bathroom downstairs here, next to the toilet, I have an Epson dot matrix
printer with 11x14 fanfold paper. Guests have to work around it.


Isn't 11x14 a bit large for TP?

 

[John Larkin]

On Sat, 09 Mar 2013 20:25:41 -0800, Robert Baer <robertbaer@localnet.com> wrote:

John Larkin wrote:
On Sat, 9 Mar 2013 16:27:24 -0600, "Tim Williams"<tmoranwms@charter.net> wrote:

Since the topic comes up here from time to time, I just thought I'd brag a
little.

I've had a Canon Pixma iP6000D for years.

- Full color
- Photo quality prints
- Refillable ink cartridges (but I'm lazy, so I buy new anyway)
- Two sided (duplex) printing (slow, but it works)
- Allows printing with "low ink" warning, in fact, you can print until it
says "okay, now you're screwed, change the ink all damned ready!"

In the last two years, I haven't had much need for it, so it's been
sitting on its table, inactive. Plugged in but turned off. Never heard
it self-cleaning or anything, I'm quite sure it's "off-off", standby only.

Last week I needed a document, so I turned it on. After this long, I'd
expect it needs at least a deep clean. But for the hell of it, I printed
a test page.

Just a few jets were sticky, not even clogged.

The test image was actually quite passable, just not up to my standards.
So I gave it a single, basic cleaning. Nearly perfect test page after
that. Good to go.

With all the P&M people do about printers, why would they buy anything
besides this and a laser?

Of course, I doubt these machines are manufactured anymore, but used units
should be as cheap as a new POS-1 printer.

Tim

I have a few Laserjet CP1525's, which are great color laser printers if you
don't print a lot. The toner price is silly for quantity printing. They seem to
be perfectly reliable, but they do whine... they clean or calibrate themselves
at random, and it's pretty dramatic.

We have a huge Sharp digital copier at work, all networked. It works as a very
nice, very fast, B-size printer and we buy toner by the pound. It will feed and
scan stacks of paper into PDFs and dump that onto a server. Very cool.

In the bathroom downstairs here, next to the toilet, I have an Epson dot matrix
printer with 11x14 fanfold paper. Guests have to work around it.


Isn't 11x14 a bit large for TP?

I have some big guests.


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

 

[mpm]

On Saturday, March 9, 2013 5:27:24 PM UTC-5, Tim Williams wrote:

Since the topic comes up here from time to time, I just thought I'd brag a

little.



I've had a Canon Pixma iP6000D for years.



- Full color

- Photo quality prints

- Refillable ink cartridges (but I'm lazy, so I buy new anyway)

- Two sided (duplex) printing (slow, but it works)

- Allows printing with "low ink" warning, in fact, you can print until it

says "okay, now you're screwed, change the ink all damned ready!"



In the last two years, I haven't had much need for it, so it's been

sitting on its table, inactive. Plugged in but turned off. Never heard

it self-cleaning or anything, I'm quite sure it's "off-off", standby only..



Last week I needed a document, so I turned it on. After this long, I'd

expect it needs at least a deep clean. But for the hell of it, I printed

a test page.



Just a few jets were sticky, not even clogged.



The test image was actually quite passable, just not up to my standards.

So I gave it a single, basic cleaning. Nearly perfect test page after

that. Good to go.



With all the P&M people do about printers, why would they buy anything

besides this and a laser?



Of course, I doubt these machines are manufactured anymore, but used units

should be as cheap as a new POS-1 printer.



Tim



--

Deep Friar: a very philosophical monk.

Website: http://seventransistorlabs.com

I've pretty much reached the conclusion that I will never be 100% satisfied with a color printer. We still have the inkjet HP something-or-other, the Brother HL-4040CN color laser (2 of those), and the previously mentioned El Cheapo Brother B/W laser. For the latter, we still haven't found the right combination of secret herbs and spices to get it to play nicely with our corporate LAN.

That said, there are a couple things that might get me closer to 100%. For instance, if staff would quit printing in color when only a few insignificant portions of the page are actually in color - such as a logo at the top of a datasheet when everything else is B/W.

We went around and set "black only" as the default but of course, not all programs enforce those settings (I guess they have their own defaults?) We should probably rename the printers too: color - B/W.

Another thing: Not everything needs to be printed in the first place.

I know I sound like the "Print Czar" or something. It's actually just a pet peeve, I guess. (And speaking of pets: maybe if we got that unicorn someone here mentioned previously as our company mascot we could DIY the blood use to make all those ink cartridges!)

 

[mpm]

On Saturday, March 9, 2013 8:21:57 PM UTC-5, John Larkin wrote:

In the bathroom downstairs here, next to the toilet, I have an Epson dot matrix printer with 11x14 fanfold paper. Guests have to work around it.

Have you considered using softer 2-ply paper?

-mpm

 

[Francesco Poderico]

On Saturday, 9 March 2013 22:58:46 UTC, Lasse Langwadt Christensen wrote:

On Mar 9, 11:15 pm, Francesco Poderico

francescopoder...@googlemail.com> wrote:

On Saturday, 9 March 2013 21:30:36 UTC, Jeff Liebermann  wrote:

On Sat, 9 Mar 2013 10:22:38 -0800 (PST),



francescopoder...@googlemail.com wrote:



I've started designing a 200 MSPS Oscilloscope with a 25 MHz analog bandwidth, 3Ksample/channel buffer.



The oscilloscope can be connected to a PC via USB, and eventually via Ethernet and WiFi.



The  trigger is ( at moment) rising, falling... auto, normal.



I would appreciate suggestions and or  comment for possible improvement and functionality that could make this oscilloscope interesting.



Francesco



There are plenty of similar USB scopes on the market with similar



specs.  Use their feature list as a checklist to see if you're missing



something.  I presume that you're asking for advice on how to make the



hardware unique in order to obtain a marketing advantage.  Most of the



product differentiation is in the software, so I'll comment only on



the hardware.  What *I* might want in a USB scope is (whether I'm



willing to pay for these is another question):



1.  USB microscope camera on the probe tip so that I can see where I'm



sticking the probe.



2.  IR thermometer with LED targeting on the probe so that I can



simultaneously measure and record any localized heating.



3.  Replacable front end so that when I inevitably blow it out, it can



be easily replaced.



4.  Built in function generator, pattern generator, arbitrary waveform



generator, two tone generator, DDS generator, white/pink noise, sweep



generator generator.  Extra points for adding AM/FM/PM/pulse



modulation.



5.  DC power output for powering active probes and assorted sensors..



6.  Presumably, it's dual channel.  If so, make it stackable via a



common bus or preferably via ethernet, so that multiple units can be



conglomerated into a 4,6,8, etc channel scope.



7.  Switchable low pass filter on input for high RF level



environments.



8.  Self test and calibration check.



9.  An accurate and readable schematic so I can fix it.



10. Security cable to keep it from getting um.... borrowed.



11. Built in smoke detector.



--



Jeff Liebermann     je...@cruzio.com



150 Felker St #D    http://www.LearnByDestroying.com



Santa Cruz CA 95060http://802.11junk.com



Skype: JeffLiebermann     AE6KS    831-336-2558



Thnanks Jeff,

I like the idea of the Cable that stop "unwanted borrowed" I will actually do this... not sure about the camera on probe ...



I may add a block diagram ( notthe full schematic) to show people how to calibrate the scope and some test points and hits to help people to self repair the scope.



also the function generator, could be a good sales point



Thanks



the first thing I would add is USB isolation (data and power) so that

when using usb and/or

powering it from usb the scope is isolated from the pc



-Lasse

Good point,
I was thinking to use an ADuM5xxxx from AD.

 

[Francesco Poderico]

On Sunday, 10 March 2013 00:16:57 UTC, Bruce Varley wrote:

francescopoderico@googlemail.com> wrote in message

news:c1ad2481-696a-4257-8242-a8c92169124b@googlegroups.com...

Hi all,

I've started designing a 200 MSPS Oscilloscope with a 25 MHz analog

bandwidth, 3Ksample/channel buffer.

The oscilloscope can be connected to a PC via USB, and eventually via

Ethernet and WiFi.

The trigger is ( at moment) rising, falling... auto, normal.



I would appreciate suggestions and or comment for possible improvement

and functionality that could make this oscilloscope interesting.



Thanks,

Francesco



Been there done that. Spent many weeks putting together a box that I was

very proud of, then purchased a Rigol that does everything it does plus a

lot more and a lot better. Is this really a good use of your time and

energy?

I get the point... and your are not the first one to tell me that.
but I believe that an oscilloscope is still an instruments a lot of electronic enthusiastic would love to have it if priced correctly.
Marketing will be the biggest challenge in a market so competitive.

 

[Nico Coesel]

Joerg <invalid@invalid.invalid> wrote:

John Larkin wrote:
On Sat, 09 Mar 2013 12:43:44 -0800, Joerg <invalid@invalid.invalid> wrote:

Jasen Betts wrote:
On 2013-03-08, Nico Coesel <nico@puntnl.niks> wrote:
Jasen Betts <jasen@xnet.co.nz> wrote:

On 2013-03-06, Nico Coesel <nico@puntnl.niks> wrote:
If its software then it is not a real sweep but a stepped sweep. If
you use that to test a resonator or a notch filter you might be in for
a nasty surprise.

Not if the software runs fast enough and is done right.
Fast enough and done right usually don't go well with an 8051. In an
ideal sweep (or FM modulation) you'd have to recalculate the step size
for every sample.
I understand that 8051 is the uC that everone that everyone loves to
hate, but the claim depends on the frequency you're running it all at.

Hate? It is just about the only uC that has 2nd source (in some of the
packages) and where you can find a capable programmer in almost every
village. What there to hate?

The architecture? The instruction set? The speed?


So what? It's a practical uC, for many reasons. In the same way that I
won't complain that my car would not perform well on the Indianapolis
racetrack. But it does ferry 1/2 ton of pellets back home rather nicely
and that matters more to me than winning some race.

An 8051 compares to ARM like a model T Ford compares to a Volkswagen
Golf / Rabbit. IMHO finding a second source for parts is becoming more
and more impossible. Just like the XR2206 8051 microcontrollers may
become extinct real soon as well.
--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------

 

[Joerg]

Nico Coesel wrote:

Joerg <invalid@invalid.invalid> wrote:

John Larkin wrote:
On Sat, 09 Mar 2013 12:43:44 -0800, Joerg <invalid@invalid.invalid> wrote:

Jasen Betts wrote:
On 2013-03-08, Nico Coesel <nico@puntnl.niks> wrote:
Jasen Betts <jasen@xnet.co.nz> wrote:

On 2013-03-06, Nico Coesel <nico@puntnl.niks> wrote:
If its software then it is not a real sweep but a stepped sweep. If
you use that to test a resonator or a notch filter you might be in for
a nasty surprise.

Not if the software runs fast enough and is done right.
Fast enough and done right usually don't go well with an 8051. In an
ideal sweep (or FM modulation) you'd have to recalculate the step size
for every sample.
I understand that 8051 is the uC that everone that everyone loves to
hate, but the claim depends on the frequency you're running it all at.

Hate? It is just about the only uC that has 2nd source (in some of the
packages) and where you can find a capable programmer in almost every
village. What there to hate?
The architecture? The instruction set? The speed?

So what? It's a practical uC, for many reasons. In the same way that I
won't complain that my car would not perform well on the Indianapolis
racetrack. But it does ferry 1/2 ton of pellets back home rather nicely
and that matters more to me than winning some race.

An 8051 compares to ARM like a model T Ford compares to a Volkswagen
Golf / Rabbit. ...

There are many situations where a Model T gets you there. When I rode in
a Model A a while ago I was pleasantly surprised how comfortable that was.

... IMHO finding a second source for parts is becoming more
and more impossible. ...

However, if it is possible one should always prefer the part that has
2nd source unless there are compelling reasons not to.

... Just like the XR2206 8051 microcontrollers may
become extinct real soon as well.

That's been said since over 15 years

--
Regards, Joerg

http://www.analogconsultants.com/

 

[John Larkin]

On Wed, 06 Mar 2013 14:48:39 -0800, Joerg <invalid@invalid.invalid> wrote:

Jamie wrote:
Nico Coesel wrote:

josephkk <joseph_barrett@sbcglobal.net> wrote:


On Sun, 03 Mar 2013 19:51:06 -0500, Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:


Joerg wrote:


Jamie wrote:
=20

Joerg wrote:



Spehro Pefhany wrote:


Oh yeah, we had a bunch that came in kits best suited for starter
electronic people from a particular source that were packaging them.
.
Also, back then surplus centers were very popular and you could find
these chips there and more than likely they were seconds but they
made their way out there in equipment where they didn't belong..

These days things are laser trimmed and that isn't such an issue any=20
more.

With today's methods of fabbing chips, I would bet a chip like that=20
could be reproduce with a much better yield and precision.

Jamie

They were sweet chips for their time, but now they are up against DDS
chips with 14+ bit dacs for not all that much. They can't compete, =
except
in the hobbyist market which way too small.


Well, FM and sweep seems to be a problem

i have a DDS function generator that does all of that and it
does not have any problems?


So do I and it dopesn't have modulation problems. But these are too big
even if I'd remove the enclosure and power supply.


I think you'll find if you don't have a latency problem with the
serial link to the chip, you should be able to do all the FMing you
want..


The problem with the uC on these little boards is not the serial link.
Well, at least not if 100Hz sweeps suffice. The problem is that they are
too small to calculate the numbers on the fly and usually have to little
flash left to store them in a LUT. Plus that would be a major
time-consuming hack.

Fancy ramped, modulated DDS sinewave generation at 200K samples/sec would be no
sweat for a $4 ARM, and you get a mux'd ADC and a DAC for free. But yes, it
would take some code slinging.


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

 

[Nico Coesel]

Francesco Poderico <francescopoderico@googlemail.com> wrote:

On Sunday, 10 March 2013 00:16:57 UTC, Bruce Varley wrote:
francescopoderico@googlemail.com> wrote in message

news:c1ad2481-696a-4257-8242-a8c92169124b@googlegroups.com...

Hi all,

I've started designing a 200 MSPS Oscilloscope with a 25 MHz analog

bandwidth, 3Ksample/channel buffer.

The oscilloscope can be connected to a PC via USB, and eventually via

Ethernet and WiFi.

The trigger is ( at moment) rising, falling... auto, normal.



I would appreciate suggestions and or comment for possible improvement

and functionality that could make this oscilloscope interesting.



Thanks,

Francesco



Been there done that. Spent many weeks putting together a box that I was

very proud of, then purchased a Rigol that does everything it does plus a

lot more and a lot better. Is this really a good use of your time and

energy?

I get the point... and your are not the first one to tell me that.
but I believe that an oscilloscope is still an instruments a lot of electronic enthusiastic would love to have it if priced correctly.
Marketing will be the biggest challenge in a market so competitive.

Did you look what a Siglent scope costs on Ebay? IIRC its about US
$180 including shipping from China. How do you expect to beat that?
BTW Lecroy sells the exact same scope for a lot more.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------

 

[Joerg]

John Larkin wrote:

On Wed, 06 Mar 2013 14:48:39 -0800, Joerg <invalid@invalid.invalid> wrote:

Jamie wrote:

[...]

I think you'll find if you don't have a latency problem with the
serial link to the chip, you should be able to do all the FMing you
want..

The problem with the uC on these little boards is not the serial link.
Well, at least not if 100Hz sweeps suffice. The problem is that they are
too small to calculate the numbers on the fly and usually have to little
flash left to store them in a LUT. Plus that would be a major
time-consuming hack.

Fancy ramped, modulated DDS sinewave generation at 200K samples/sec would be no
sweat for a $4 ARM, and you get a mux'd ADC and a DAC for free. But yes, it
would take some code slinging.

And I'll probably do that if this becomes a product, with whatever
processor the local SW folks can handle without a major learning curve.
Just not right now, got to watch work load, expenses and time line. So
it'll be analog for now.

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Jamie]

Nico Coesel wrote:

Francesco Poderico <francescopoderico@googlemail.com> wrote:


On Sunday, 10 March 2013 00:16:57 UTC, Bruce Varley wrote:

francescopoderico@googlemail.com> wrote in message

news:c1ad2481-696a-4257-8242-a8c92169124b@googlegroups.com...


Hi all,

I've started designing a 200 MSPS Oscilloscope with a 25 MHz analog

bandwidth, 3Ksample/channel buffer.

The oscilloscope can be connected to a PC via USB, and eventually via

Ethernet and WiFi.

The trigger is ( at moment) rising, falling... auto, normal.

I would appreciate suggestions and or comment for possible improvement

and functionality that could make this oscilloscope interesting.

Thanks,

Francesco



Been there done that. Spent many weeks putting together a box that I was

very proud of, then purchased a Rigol that does everything it does plus a

lot more and a lot better. Is this really a good use of your time and

energy?

I get the point... and your are not the first one to tell me that.
but I believe that an oscilloscope is still an instruments a lot of electronic enthusiastic would love to have it if priced correctly.
Marketing will be the biggest challenge in a market so competitive.


Did you look what a Siglent scope costs on Ebay? IIRC its about US
$180 including shipping from China. How do you expect to beat that?
BTW Lecroy sells the exact same scope for a lot more.

Yeah, but it has Lecroy's name on it and that's like GOLD!!!!!!!!!!!

Jamie

 

[John Larkin]

On Sun, 10 Mar 2013 10:05:34 -0700, Joerg <invalid@invalid.invalid> wrote:

John Larkin wrote:
On Wed, 06 Mar 2013 14:48:39 -0800, Joerg <invalid@invalid.invalid> wrote:

Jamie wrote:

[...]

I think you'll find if you don't have a latency problem with the
serial link to the chip, you should be able to do all the FMing you
want..

The problem with the uC on these little boards is not the serial link.
Well, at least not if 100Hz sweeps suffice. The problem is that they are
too small to calculate the numbers on the fly and usually have to little
flash left to store them in a LUT. Plus that would be a major
time-consuming hack.

Fancy ramped, modulated DDS sinewave generation at 200K samples/sec would be no
sweat for a $4 ARM, and you get a mux'd ADC and a DAC for free. But yes, it
would take some code slinging.


And I'll probably do that if this becomes a product, with whatever
processor the local SW folks can handle without a major learning curve.
Just not right now, got to watch work load, expenses and time line. So
it'll be analog for now.

If you do go ARM, let me know if you'd like some example C code to butcher. We
have an app that uses an ADC interrupt to do a filtering + PID algorithm, ADC in
to DAC out, on an LPC1754. The algorithm is pretty fancy, and we run it at 100
KHz with the internal uP clock throttled down to 50 MHz. We pay $3.55 each,
pre-programmed by a distributor.

Bring your programmer and we'll go to Zeitgeist and we'll explain our code and
the DDS theory. Your treat, of course.

Today I'm writing a PowerBasic program to graph a bunch of thermocouple
temperature controller params vs time. It's slow, graphing coffee cups of hot
water cooling off. Thermal stuff is always tedious.

You can keep a thermocouple to within a tenth degree of 25C by holding the lead
in your mouth, roughly 6" from the junction, sliding it a bit left or right to
keep the temp on target, varying the thermal conduction. You can even do it
hands-off with a bit of practice.


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

 

[John Devereux]

nico@puntnl.niks (Nico Coesel) writes:

Francesco Poderico <francescopoderico@googlemail.com> wrote:

On Sunday, 10 March 2013 00:16:57 UTC, Bruce Varley wrote:
francescopoderico@googlemail.com> wrote in message

news:c1ad2481-696a-4257-8242-a8c92169124b@googlegroups.com...

Hi all,

I've started designing a 200 MSPS Oscilloscope with a 25 MHz analog

bandwidth, 3Ksample/channel buffer.

The oscilloscope can be connected to a PC via USB, and eventually via

Ethernet and WiFi.

The trigger is ( at moment) rising, falling... auto, normal.



I would appreciate suggestions and or comment for possible improvement

and functionality that could make this oscilloscope interesting.



Thanks,

Francesco



Been there done that. Spent many weeks putting together a box that I was

very proud of, then purchased a Rigol that does everything it does plus a

lot more and a lot better. Is this really a good use of your time and

energy?

I get the point... and your are not the first one to tell me that.
but I believe that an oscilloscope is still an instruments a lot of electronic enthusiastic would love to have it if priced correctly.
Marketing will be the biggest challenge in a market so competitive.

Did you look what a Siglent scope costs on Ebay? IIRC its about US
$180 including shipping from China. How do you expect to beat that?
BTW Lecroy sells the exact same scope for a lot more.

I've wanted to make something like a "dynamic signal analyser" that goes
up to 1 or 10 MHz, instead of 100kHz like they all seem to.

High dynamic range (16+ bit) low noise, with arb generator.

I've got one of these, and I like it, but it is a big old slow beast of
a thing:

<http://www.teknetelectronics.com/Search.asp?p_ID=13689&pDo=DETAIL>


--

John Devereux

 

[Spehro Pefhany]

On Sun, 10 Mar 2013 11:34:49 -0700, the renowned John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

You can keep a thermocouple to within a tenth degree of 25C by holding the lead
in your mouth, roughly 6" from the junction, sliding it a bit left or right to
keep the temp on target, varying the thermal conduction. You can even do it
hands-off with a bit of practice.

Pro tip: Remove thermocouple element from Inconel 600 thermowell
before attempting.

http://www.tantaline.com/files/billeder/Thermowell_Series385S.jpg



Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[John Larkin]

On Sun, 10 Mar 2013 15:00:24 -0400, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

On Sun, 10 Mar 2013 11:34:49 -0700, the renowned John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:


You can keep a thermocouple to within a tenth degree of 25C by holding the lead
in your mouth, roughly 6" from the junction, sliding it a bit left or right to
keep the temp on target, varying the thermal conduction. You can even do it
hands-off with a bit of practice.


Pro tip: Remove thermocouple element from Inconel 600 thermowell
before attempting.

http://www.tantaline.com/files/billeder/Thermowell_Series385S.jpg

I wonder what's the temperature of a well-stirred mixture of crushed ice, rum,
and Coke. That deserves further research.


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

 

[Nico Coesel]

Francesco Poderico <francescopoderico@googlemail.com> wrote:

On Sunday, 10 March 2013 16:35:29 UTC, Nico Coesel wrote:
Francesco Poderico wrote:



very proud of, then purchased a Rigol that does everything it does plus a
lot more and a lot better. Is this really a good use of your time and
energy?

I get the point... and your are not the first one to tell me that.
but I believe that an oscilloscope is still an instruments a lot of electronic enthusiastic would love to have it if priced correctly.
Marketing will be the biggest challenge in a market so competitive.

Did you look what a Siglent scope costs on Ebay? IIRC its about US
$180 including shipping from China. How do you expect to beat that?
BTW Lecroy sells the exact same scope for a lot more.


it's challenging but not impossible.
I agree...It is very difficult to compete with China, but not impossible if we point on quality.

If you think the Chinese can't make quality stuff then you've made
your first big mistake. If its good enough for Lecroy to stick their
badge on the quality bit is in order.

So re-think your competitive edge. Remember that a good DSO is 5%
hardware and 95% software. So even if you get the hardware right you
are still nowhere near a sellable product.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------