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Groups > comp.arch.embedded > #21482
| From | Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> |
|---|---|
| Newsgroups | sci.electronics.design, comp.arch.embedded |
| Subject | Re: waveform display in browser |
| Date | 2015-07-23 19:56 -0400 |
| Organization | A noiseless patient Spider |
| Message-ID | <55B17F39.3040209@electrooptical.net> (permalink) |
| References | (4 earlier) <l6o2ra56j3k3q75f4s1k6ekivq4knp3qij@4ax.com> <morp62$aso$1@dont-email.me> <tjq2rah4241gu7i0tloqhi8sn4jjbf0st4@4ax.com> <MPqdnYnexK8q7SzInZ2dnUU7-SudnZ2d@giganews.com> <66t2ra1mebptuknfc16kc11ko5m07t4hfv@4ax.com> |
Cross-posted to 2 groups.
On 7/23/2015 7:22 PM, John Larkin wrote:
> On Thu, 23 Jul 2015 17:54:47 -0500, Tim Wescott
> <seemywebsite@myfooter.really> wrote:
>
>> On Thu, 23 Jul 2015 15:30:11 -0700, John Larkin wrote:
>>
>>> On Fri, 24 Jul 2015 01:19:09 +0300, Dimiter_Popoff <dp@tgi-sci.com>
>>> wrote:
>>>
>>>> On 24.7.2015 ?. 00:50, John Larkin wrote:
>>>>> On Fri, 24 Jul 2015 00:13:19 +0300, Dimiter_Popoff <dp@tgi-sci.com>
>>>>> wrote:
>>>>>
>>>>>> On 23.7.2015 ?. 23:49, rickman wrote:
>>>>>>> On 7/23/2015 4:34 PM, Phil Hobbs wrote:
>>>>>>>> On 7/23/2015 2:18 PM, John Larkin wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> I'm designing a tachometer box and it will have a web page
>>>>>>>>> interface as one way to talk to it. I thought it would be cool to
>>>>>>>>> include an ADC so we could display waveforms, too. My software
>>>>>>>>> guys here are mostly embedded types so we don't know a lot about
>>>>>>>>> Javascript and such. I did a little searching and mostly found
>>>>>>>>> things for displaying audio envelope cartoons; I want a real
>>>>>>>>> oscilloscope-looking thing, so users can see what happens as they
>>>>>>>>> change gains and filtering and trigger level settings. Dual trace
>>>>>>>>> would be nice, the analog waveform and corresponding comparator
>>>>>>>>> outputs.
>>>>>>>>>
>>>>>>>>> Has anybody done this? We'd consider getting outside help, either
>>>>>>>>> advice or actual coding.
>>>>>>>>>
>>>>>>>>> I assume our box will, through some port, deliver HTML,
>>>>>>>>> Javascript, and maybe some zipped JS libraries to the browser. And
>>>>>>>>> the company logo of course. The browser will send us text strings
>>>>>>>>> to parse if the user wants to change parameters or such. We would
>>>>>>>>> also deliver blocks of waveform data on request. That's my PHB
>>>>>>>>> perspective on things; I'm just the hardware designer.
>>>>>>>>>
>>>>>>>>>
>>>>>>>> One approach is a CGI script that runs gnuplot under the covers.
>>>>>>>> IIRC quite a few folks do that. (I'm a static HTML guy myself.)
>>>>>>>
>>>>>>> Isn't there an actual oscilloscope display package under Linux? It
>>>>>>> should be fairly straightforward to drive that from an internet
>>>>>>> connection. I guess requiring the customer to installing such a
>>>>>>> package is not preferred.
>>>>>>>
>>>>>>>
>>>>>> He is after a browser plugin - something like VNC, the way I do it on
>>>>>> our spectrometers (I do not use a plugin but I could if I wanted to).
>>>>>
>>>>> Actually, I don't want a plugin, just a way for the browser to display
>>>>> a waveform, using some javascript. We can store any reasonable zipped
>>>>> javascript libraries in our gadget and deliver them to the browser.
>>>>
>>>> I am not sure I have seen that done for live graphics - then scaling,
>>>> perhaps autoranging etc., even if doable it would be a massive pain to
>>>> support with all browsers as they keep on evolving.
>>>> Your best bet might be to produce locally a .gif (or .png or whatever)
>>>> bitmap, maintain it live and persuade the browser to refresh it
>>>> regularly. Don't know how the latter is to be done though.
>>>
>>> We could do that in the FPGA! If nobody murders me for suggesting it.
>>
>> I don't know how to persuade a browser to auto-refresh, but GIF format
>> uses run-length limiting for compression. That means that line drawings
>> of few colors tend to be very small -- you'll use up way more bits on
>> text than on the pictures.
>
> There is some simple HTML thing that makes a page reload periodically.
> That's apparently easy to do.
>
> A BMP would be easy to make inside the FPGA, but that would be slow to
> load. Maybe the ARM could make a GIF or PNG. That would avoid all the
> javascript nonsense. We'd just have to find the code somewhere.
>
> This bmp is 556K bytes.
>
> https://dl.dropboxusercontent.com/u/53724080/Circuits/Current_Limiters/LM317L_ilim.bmp
>
> That wouldn't be really terrible to send once a second or so over 100
> MBPS Ethernet. But my FPGA doesn't have enough RAM.
>
>
Bumpfiles are simple, so that's a win. I usually generate those in my
code, then (in a script) call ImageMagick's 'convert' to make them into
.jpg or .png or whatever.
Cheers
Phil [system("convert foo.bmp foo.png") covers a multitude of sins]Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
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waveform display in browser John Larkin <jlarkin@highlandtechnology.com> - 2015-07-23 11:18 -0700
Re: waveform display in browser Joerg <news@analogconsultants.com> - 2015-07-23 11:53 -0700
Re: waveform display in browser Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2015-07-23 16:34 -0400
Re: waveform display in browser rickman <gnuarm@gmail.com> - 2015-07-23 16:49 -0400
Re: waveform display in browser Dimiter_Popoff <dp@tgi-sci.com> - 2015-07-24 00:13 +0300
Re: waveform display in browser rickman <gnuarm@gmail.com> - 2015-07-23 17:39 -0400
Re: waveform display in browser John Larkin <jlarkin@highlandtechnology.com> - 2015-07-23 14:50 -0700
Re: waveform display in browser Dimiter_Popoff <dp@tgi-sci.com> - 2015-07-24 01:19 +0300
Re: waveform display in browser John Larkin <jlarkin@highlandtechnology.com> - 2015-07-23 15:30 -0700
Re: waveform display in browser rickman <gnuarm@gmail.com> - 2015-07-23 18:46 -0400
Re: waveform display in browser Tim Wescott <seemywebsite@myfooter.really> - 2015-07-23 17:54 -0500
Re: waveform display in browser John Larkin <jlarkin@highlandtechnology.com> - 2015-07-23 16:22 -0700
Re: waveform display in browser Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2015-07-23 19:56 -0400
Re: waveform display in browser Tim Wescott <seemywebsite@myfooter.really> - 2015-07-24 14:55 -0500
Re: waveform display in browser John Larkin <jlarkin@highlandtechnology.com> - 2015-07-24 14:11 -0700
Re: waveform display in browser Tim Wescott <seemywebsite@myfooter.really> - 2015-07-24 17:00 -0500
Re: waveform display in browser Herbert Kleebauer <klee@unibwm.de> - 2015-07-25 09:04 +0200
Re: waveform display in browser Tim Wescott <seemywebsite@myfooter.really> - 2015-07-24 14:58 -0500
Re: waveform display in browser Grant Edwards <invalid@invalid.invalid> - 2015-07-24 20:15 +0000
Re: waveform display in browser Tim Wescott <seemywebsite@myfooter.really> - 2015-07-24 16:48 -0500
Re: waveform display in browser Grant Edwards <invalid@invalid.invalid> - 2015-07-24 22:08 +0000
Re: waveform display in browser Clifford Heath <no.spam@please.net> - 2015-07-24 22:46 +1000
Re: waveform display in browser Grant Edwards <invalid@invalid.invalid> - 2015-07-25 14:32 +0000
Re: waveform display in browser Jasen Betts <jasen@xnet.co.nz> - 2015-07-24 22:44 +0000
Re: waveform display in browser Jasen Betts <jasen@xnet.co.nz> - 2015-07-24 23:31 +0000
Re: waveform display in browser Clifford Heath <no.spam@please.net> - 2015-07-24 22:49 +1000
Re: waveform display in browser Jasen Betts <jasen@xnet.co.nz> - 2015-07-25 09:28 +0000
Re: waveform display in browser Clifford Heath <no.spam@please.net> - 2015-07-25 08:43 +1000
Re: waveform display in browser Jasen Betts <jasen@xnet.co.nz> - 2015-07-25 22:27 +0000
Re: waveform display in browser Clifford Heath <no.spam@please.net> - 2015-07-25 20:57 +1000
Re: waveform display in browser Jasen Betts <jasen@xnet.co.nz> - 2015-07-24 22:41 +0000
Re: waveform display in browser rickman <gnuarm@gmail.com> - 2015-07-24 22:03 -0400
Re: waveform display in browser Tim Wescott <seemywebsite@myfooter.really> - 2015-07-24 15:05 -0500
Re: waveform display in browser Jasen Betts <jasen@xnet.co.nz> - 2015-07-23 21:37 +0000
Re: waveform display in browser John Larkin <jlarkin@highlandtechnology.com> - 2015-07-23 15:32 -0700
Re: waveform display in browser Martin Riddle <martin_ridd@verizon.net> - 2015-07-23 20:24 -0400
Re: waveform display in browser John Larkin <jlarkin@highlandtechnology.com> - 2015-07-23 21:08 -0700
Re: waveform display in browser Martin Riddle <martin_ridd@verizon.net> - 2015-07-24 07:52 -0400
Re: waveform display in browser Jasen Betts <jasen@xnet.co.nz> - 2015-07-24 14:08 +0000
Re: waveform display in browser Clifford Heath <no.spam@please.net> - 2015-07-24 22:53 +1000
Re: waveform display in browser Jasen Betts <jasen@xnet.co.nz> - 2015-07-25 09:46 +0000
Re: waveform display in browser Clifford Heath <no.spam@please.net> - 2015-07-25 08:46 +1000
Re: waveform display in browser Clifford Heath <no.spam@please.net> - 2015-07-24 00:37 +1000
Re: waveform display in browser Martin Brown <|||newspam|||@nezumi.demon.co.uk> - 2015-07-24 11:46 +0100
Re: waveform display in browser YD <ydtechHAT@techie.com> - 2015-07-24 14:25 -0300
Re: waveform display in browser John Larkin <jlarkin@highlandtechnology.com> - 2015-07-24 10:55 -0700
Re: waveform display in browser rickman <gnuarm@gmail.com> - 2015-07-24 14:09 -0400
Re: waveform display in browser Grant Edwards <invalid@invalid.invalid> - 2015-07-24 18:42 +0000
Re: waveform display in browser YD <ydtechHAT@techie.com> - 2015-07-24 19:12 -0300
Re: waveform display in browser Grant Edwards <invalid@invalid.invalid> - 2015-07-25 14:36 +0000
Re: waveform display in browser Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2015-07-24 14:55 -0400
Re: waveform display in browser John Larkin <jlarkin@highlandtechnology.com> - 2015-07-27 17:52 -0700
Re: waveform display in browser Phil Hobbs <hobbs@electrooptical.net> - 2015-07-28 17:58 -0400
Re: waveform display in browser "jurem" <51422@EmbeddedRelated> - 2015-07-28 09:49 -0500
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