Post by thread:[EE] Oscilloscopes...

William Chops Westfield wrote: > I *LIKE* my TDS-210, I have one for my use at a customer, so have acquired some experience with it. My biggest gripe with it is that the horizontal trigger position stays fixed in time relative to the center of the screen when you change time scales. It does not stay fixed in screen position as you would want. This may sound like a minor nit, but when you use the scope regularly it gets REALLY ANNOYING. Especially when you expand the time scale the trigger position is suddenly gone because it got moved off screen. If you're not used to this "feature", you start fumbling thru the menus trying to figure out how you accidentally made the trigger display go away. After you're used to it you have to remember to move the trigger to the center, expand the time scale slowly, keep moving the trigger back to the center unless you got it right on center the first time else the error will eventually blow up and move it off screen, get to the right time scale, then move the trigger back to where you had it in the first place. It gets to the point where you dread changing the time scale so you don't have to mess around with the trigger. Either that or leave the trigger in the center of the screen, but that gets annoying too since that usually wastes half the screen. It also pisses me off because we all know it would have been a simple difference in the firmware to have done it right. I understand things like bandwidth, sample depth, number of channels, etc cost money and that a low end scope will have less of them, but doing this right would have cost nothing extra. Other things that are "unimpressive" but somewhat more forgiveable in a low end scope are the relatively low screen resolution, particularly vertically, and the surprisingly high noise especially at faster sample rates. ****************************************************************** Embed Inc, Littleton Massachusetts, (978) 742-9014. #1 PIC consultant in 2004 program year. http://www.embedinc.com/products

kravnus wolf wrote: > Aligent VS tek. > > Does it convince you to buy tek? Not sure it is all > marketing talk there....... I don't know if it's the same page as the link you posted, but I did see a comparison between Tek and Agilent. Unfortunately this was produced by Tek, so any advantages of the Agilent might have were not mentioned. It does provide a list of things to look into and make up your own mind about, but I'm not going to take anything from it beyond that. I'd like to see a similar blurb from Agilent. Between the two one might even be able to get somewhere near the truth. ****************************************************************** Embed Inc, Littleton Massachusetts, (978) 742-9014. #1 PIC consultant in 2004 program year. http://www.embedinc.com/products

On Mon, 3 Apr 2006 07:37:17 -0400, you wrote: {Quote hidden}>William Chops Westfield wrote: >> I *LIKE* my TDS-210, > >I have one for my use at a customer, so have acquired some experience with >it. My biggest gripe with it is that the horizontal trigger position stays >fixed in time relative to the center of the screen when you change time >scales. It does not stay fixed in screen position as you would want. This >may sound like a minor nit, but when you use the scope regularly it gets >REALLY ANNOYING. Especially when you expand the time scale the trigger >position is suddenly gone because it got moved off screen. If you're not >used to this "feature", you start fumbling thru the menus trying to figure >out how you accidentally made the trigger display go away. After you're >used to it you have to remember to move the trigger to the center, expand >the time scale slowly, keep moving the trigger back to the center unless you >got it right on center the first time else the error will eventually blow up >and move it off screen, get to the right time scale, then move the trigger >back to where you had it in the first place. It gets to the point where you >dread changing the time scale so you don't have to mess around with the >trigger. Either that or leave the trigger in the center of the screen, but >that gets annoying too since that usually wastes half the screen. It's this sort of niggle that makes evaluating scopes so important to see how well you can live with them. Incidentally the Agilents zoom around the centre (or optionally one div from the left or right side - I prefer the left option as most of the time you are interested in what happens after the trigger).

{Quote hidden}>-----Original Message----- >From: spam_OUTpiclist-bouncesTakeThisOuTmit.edu [.....piclist-bouncesKILLspam@spam@mit.edu] >Sent: 03 April 2006 13:09 >To: Microcontroller discussion list - Public. >Subject: Re: [EE] Oscilloscopes... > > >On Mon, 3 Apr 2006 07:37:17 -0400, you wrote: > >>William Chops Westfield wrote: >>> I *LIKE* my TDS-210, >> >>I have one for my use at a customer, so have acquired some experience >>with it. My biggest gripe with it is that the horizontal trigger >>position stays fixed in time relative to the center of the >screen when >>you change time scales. It does not stay fixed in screen position as >>you would want. This may sound like a minor nit, but when >you use the >>scope regularly it gets REALLY ANNOYING. Especially when you expand >>the time scale the trigger position is suddenly gone because it got >>moved off screen. If you're not used to this "feature", you start >>fumbling thru the menus trying to figure out how you >accidentally made >>the trigger display go away. After you're used to it you have to >>remember to move the trigger to the center, expand the time scale >>slowly, keep moving the trigger back to the center unless you got it >>right on center the first time else the error will eventually blow up >>and move it off screen, get to the right time scale, then move the >>trigger back to where you had it in the first place. It gets to the >>point where you dread changing the time scale so you don't >have to mess >>around with the trigger. Either that or leave the trigger in the >>center of the screen, but that gets annoying too since that usually >>wastes half the screen. > > >It's this sort of niggle that makes evaluating scopes so >important to see how well you can live with them. Incidentally >the Agilents zoom around the centre (or optionally one div >from the left or right side >- I prefer the left option as most of the time you are >interested in what happens after the trigger). Out Aglient 54622D's work the same as the Tek, i.e. if the time between the trigger point and middle of the screen stays constant, so zomming in moves the trigger position to the left or right unless it's bang on zero to start with. It is a bit annoying as it can take an impossibly long time to move the trigger back on the screen with the hoizontal postion control if you have zoomed in considerably. Normaly you have to zoom back out, zero the trigger and then zoom back in. Apart from that one niggle they are superb scopes though, I would love to have one at home. Regards Mike ======================================================================= This e-mail is intended for the person it is addressed to only. The information contained in it may be confidential and/or protected by law. If you are not the intended recipient of this message, you must not make any use of this information, or copy or show it to any person. Please contact us immediately to tell us that you have received this e-mail, and return the original to us. Any use, forwarding, printing or copying of this message is strictly prohibited. No part of this message can be considered a request for goods or services. =======================================================================

Olin Lathrop wrote: >> I *LIKE* my TDS-210, > > I have one for my use at a customer, so have acquired some experience with > it. My biggest gripe with it is that the horizontal trigger position stays > fixed in time relative to the center of the screen when you change time > scales. It does not stay fixed in screen position as you would want. This > may sound like a minor nit, but when you use the scope regularly it gets > REALLY ANNOYING. Especially when you expand the time scale the trigger > position is suddenly gone because it got moved off screen. If you're not > used to this "feature", you start fumbling thru the menus trying to figure > out how you accidentally made the trigger display go away. I think it depends a bit whether that's a feature or an annoyance. I think the logic behind is that whatever you want to look at is at or around 0, whereas the trigger is where it needs to be so that what you want to look at is at or around 0. Following this line of thought, it makes sense to keep the 0 point fixed on the screen, not the trigger point. I took me a bit to get used to it, but it's at least not without logic and makes some sense. Probably best would be to be able to move the 0 point around on the screen, or to have a configuration item that allows to choose whether the trigger point or the 0 point is fixed. OTOH, when I use the zoom feature, all this doesn't really matter -- and that's what I use mostly when I want to zoom in on a part of the screen. Quite often it's neither the part around the trigger point nor the part around the 0 point that I want to zoom in on, and the zoom feature conveniently lets me preview and adjust in the coarse time base view what part of the signal I'll be looking at after zooming in. Gerhard

>Out Aglient 54622D's work the same as the Tek, i.e. if the time between the trigger point and middle of the screen stays constant, so zomming in moves the trigger position to the left or right unless it's bang on zero to start with. It is a bit annoying as it can take an impossibly long time to move the trigger back on the screen with the hoizontal postion control if you have zoomed in considerably. Normaly you have to zoom back out, zero the trigger and then zoom back in. Apart from that one niggle they are superb scopes though, I would love to have one at home. This is an inherent issue with deep-memory scopes, and there is a really nice way that it could be overcome if they thought about it- a single button to reset the delay to zero. A 'push-to-zero' function on the delay time knob would be absolutely perfect for this. On my old 54645D, I actually made up a little external button-box to provide this function (and a few others) by sending the appropriate RS232 command.

Mike Harrison wrote: > Incidentally the Agilents zoom around the centre (or optionally one div > from the left or right side - I prefer the left option as most of the > time you are interested in what happens after the trigger). Exactly. I usually have the trigger one division from the left edge. After all, an analog scope basically has the trigger permanently fixed at the left edge. Tek committed a major blunder by not at least making their digital scope capable of acting like an old fashioned analog scope many people will be used to. It doesn't have to be the only mode, but it should be there. I still don't understand why there has to be a mode to select where to zoom the time scale around. Why is it that nobody implements the obvious answer of zooming around the current trigger position, at least as an optional mode? It might be useful to have other modes, but that's the one I would use 99% of the time and would be fine with as the only mode in a low end scope. It seems they got fancy because they could but forgot to think about it. It feels like the features were implemented by a bunch of software weenies that never used a scope. In the end the optimized for the 1% case at the expense of the 99% case. ****************************************************************** Embed Inc, Littleton Massachusetts, (978) 742-9014. #1 PIC consultant in 2004 program year. http://www.embedinc.com/products

On Mon, 3 Apr 2006 09:11:19 -0400, you wrote: {Quote hidden}>Mike Harrison wrote: >> Incidentally the Agilents zoom around the centre (or optionally one div >> from the left or right side - I prefer the left option as most of the >> time you are interested in what happens after the trigger). > >Exactly. I usually have the trigger one division from the left edge. After >all, an analog scope basically has the trigger permanently fixed at the left >edge. Tek committed a major blunder by not at least making their digital >scope capable of acting like an old fashioned analog scope many people will >be used to. It doesn't have to be the only mode, but it should be there. > >I still don't understand why there has to be a mode to select where to zoom >the time scale around. Why is it that nobody implements the obvious answer >of zooming around the current trigger position, at least as an optional >mode? It might be useful to have other modes, but that's the one I would >use 99% of the time and would be fine with as the only mode in a low end >scope. It seems they got fancy because they could but forgot to think about >it. It feels like the features were implemented by a bunch of software >weenies that never used a scope. In the end the optimized for the 1% case >at the expense of the 99% case. > Certainly add it as an option, but the main benefit I find of deep-memory scopes is you don't need to worry too much about getting the right trigger point - just grab a bunch of time and zoom in. Therefore the point you want to zoom in on is almost always NOT the trigger point, so centering the zoom on a fixed 'place on the screen' is generally more intuitive than centering on the trigger.

On Apr 3, 2006, at 4:37 AM, Olin Lathrop wrote: > It also pisses me off because we all know it would have been > a simple difference in the firmware to have done it right. I > understand things like bandwidth, sample depth, number of > channels, etc cost money and that a low end scope will have > less of them, but doing this right would have cost nothing extra. > I wonder if anyone will ever sell an open-source oscilloscope? Don't like the way the SW works? Fix it yourself, or download the "unstable with enhanced extra knobs" version from your favorite repository. Since a lot of the high end scopes these days seem to be essentially PC clones as the Display/UI, it's not unthinkable. BillW

Actually from the amount of members on the list and the quality we have I am suprise we don't build one as a team. Hint hint ;) John --- William Chops Westfield <westfwKILLspammac.com> wrote: {Quote hidden}> > On Apr 3, 2006, at 4:37 AM, Olin Lathrop wrote: > > > It also pisses me off because we all know it would > have been > > a simple difference in the firmware to have done > it right. I > > understand things like bandwidth, sample depth, > number of > > channels, etc cost money and that a low end scope > will have > > less of them, but doing this right would have cost > nothing extra. > > > I wonder if anyone will ever sell an open-source > oscilloscope? > Don't like the way the SW works? Fix it yourself, > or download > the "unstable with enhanced extra knobs" version > from your favorite > repository. Since a lot of the high end scopes > these days seem to > be essentially PC clones as the Display/UI, it's not > unthinkable. > > BillW > --

In message <.....59b85d8f05969c249e60a120e09bab02KILLspam.....mac.com>> William "Chops" Westfield <EraseMEwestfwspam_OUTTakeThisOuTmac.com> wrote: > I wonder if anyone will ever sell an open-source oscilloscope? > Don't like the way the SW works? Fix it yourself, or download > the "unstable with enhanced extra knobs" version from your favorite > repository. Since a lot of the high end scopes these days seem to > be essentially PC clones as the Display/UI, it's not unthinkable. I'd love to do something like that. I can do the software and probably the digital hardware, but I have absolutely no idea how to go about designing high-bandwidth low-noise amplifiers and such for the input circuitry. A DSO isn't *that* complex - when you boil it down to its essentials, you've got: - Front end amplifier (1 per channel) - A/D converter / acquisition circuitry (1 per channel) - Heavily filtered low-noise power supply - High speed RAM (SDRAM these days, though 10nS SRAM would be quite suitable if you could live with the relatively low data density) - Acquisition controller - Trigger circuitry (or just leave the ADC acquiring all the time and implement this in the acq controller) - CPU interface (PCI?) - CPU, display and UI (PC?) It would certainly be fun to build something that gave Tek's low- to mid-range scopes a run for their money :) Anyone want to join me? :P -- Phil. | Kitsune: Acorn RiscPC SA202 64M+6G ViewFinder philpemspam_OUTdsl.pipex.com | Cheetah: Athlon64 3200+ A8VDeluxeV2 512M+100G http://www.philpem.me.uk/ | Tiger: Toshiba SatPro4600 Celeron700 256M+40G

On Mon, 03 Apr 2006 17:58:28 +0100, you wrote: {Quote hidden}>In message <KILLspam59b85d8f05969c249e60a120e09bab02KILLspammac.com>> > William "Chops" Westfield <RemoveMEwestfwTakeThisOuTmac.com> wrote: > >> I wonder if anyone will ever sell an open-source oscilloscope? >> Don't like the way the SW works? Fix it yourself, or download >> the "unstable with enhanced extra knobs" version from your favorite >> repository. Since a lot of the high end scopes these days seem to >> be essentially PC clones as the Display/UI, it's not unthinkable. > >I'd love to do something like that. I can do the software and probably the >digital hardware, but I have absolutely no idea how to go about designing >high-bandwidth low-noise amplifiers and such for the input circuitry. > >A DSO isn't *that* complex - when you boil it down to its essentials, you've >got: > - Front end amplifier (1 per channel) > - A/D converter / acquisition circuitry (1 per channel) > - Heavily filtered low-noise power supply > - High speed RAM (SDRAM these days, though 10nS SRAM would be quite > suitable if you could live with the relatively low data density) > - Acquisition controller > - Trigger circuitry (or just leave the ADC acquiring all the time and > implement this in the acq controller) > - CPU interface (PCI?) > - CPU, display and UI (PC?) > >It would certainly be fun to build something that gave Tek's low- to >mid-range scopes a run for their money :) > >Anyone want to join me? :P It gets more interesting when you want a more responsive acquisition-to-display interface though (Tek DPO etc.) Also, SDRAM only gives decent performance in bursts, so a SRAM buffer would also be necessary. Both of these could be done in a not-too expensive FPGA. This would be a good base to start with perhaps : http://www.enterpoint.co.uk/moelbryn/raggedstone1.html

{Quote hidden}> -----Original Message----- > From: spamBeGonepiclist-bouncesspamBeGonemit.edu > [TakeThisOuTpiclist-bouncesEraseMEspam_OUTmit.edu] On Behalf Of William Chops Westfield > Sent: Monday, April 03, 2006 7:28 PM > To: Microcontroller discussion list - Public. > Subject: Re: [EE] Oscilloscopes... > > > On Apr 3, 2006, at 9:55 AM, kravnus wolf wrote: > >> [open source Osilloscope] > > > Actually from the amount of members on the list and the quality we > > have I am suprise we don't build one as a team. Hint hint ;) > > I don't WANT to build one. That's *HARD*; high precision > analog design is SCARY. What I want is to be able to take a > commercially purchased unit and just TWEAK the software a > little bit so that it ends up more like the way I want it to be... > > BillW Well Bitscope is avaible with both commercial and free open source software, Cost from some $300 or so. With best regards Tomas Larsson Sweden http://www.naks.mine.nu for downloads etc. ftp://ktl.mine.nu for uploads. Or use the free http://www.yousendit.com service. Verus Amicus Est Tamquam Alter Idem

One of the newer Tek scopes uses JAVA. (TDS 700) http://www.tektronix.com/Measurement/cgi-bin/framed.pl?Document=/Measurement/Products/press/javascope/eng/index.html&FrameSet=oscilloscopes Tektronix Embraces JavaTM Technology "BEAVERTON, OREGON (March 24, 1998) -- Meeting market demand for swift access to application-specific measurement capabilities, Tektronix, Inc. (NYSE: TEK) today introduced the first-ever test and measurement instrument implementation of JavaTM technology. This technology, which is to be included by Tektronix with its future high-end oscilloscopes, includes technology licensed by Sun Microsystems, Inc. " So the trick would be decompiling an 'update' to see how things tick. R William Chops Westfield wrote: {Quote hidden}> On Apr 3, 2006, at 4:37 AM, Olin Lathrop wrote: > > >>It also pisses me off because we all know it would have been >>a simple difference in the firmware to have done it right. I >>understand things like bandwidth, sample depth, number of >>channels, etc cost money and that a low end scope will have >>less of them, but doing this right would have cost nothing extra. >> > > I wonder if anyone will ever sell an open-source oscilloscope? > Don't like the way the SW works? Fix it yourself, or download > the "unstable with enhanced extra knobs" version from your favorite > repository. Since a lot of the high end scopes these days seem to > be essentially PC clones as the Display/UI, it's not unthinkable. > > BillW

On Apr 3, 2006, at 11:25 AM, Robert Rolf wrote: >> I don't WANT to build one. > Like the many hacks based on the Linksys WRT54G routers, which are > essentially running a linux kernal. > Yes, exactly! Although in that case I think only enough of the official software is "open source" that people have been able to replace it wholesale; A sort of "we didn't really mean for this to be open source but we got caught by the GPL. Oops." SW that was intended to be open source from the start would be better. The situation with Tivo is probably a better example. Although - I think the official theory is that all other WRT54G software is a "support nightmare." (note "theory" - I'm not sure that this is true.) Newer versions of the box labeled WRT54G have different HW, the official software is no longer linux based, and the third-party images don't run. For which we were duly dinged by the open source community. (though I can see both sides of THAT.) BillW

> EXTREMELY unlikely. > We collectively can't even agree on a PIC programmer design. > The amount of expertise on this list is considerable, but > with that comes a.. "diversity of opinion"... Yeah, that's > the right word, I think. :-) Before anyone decides to try doing another "group project" PLEASE go to the archive and read the threads on the last group design that was attempted on the piclist. Search for CUMP or... What was the other one called? The development kit thing? --- James Newton: PICList webmaster/Admin RemoveMEjamesnewtonTakeThisOuTpiclist.com 1-619-652-0593 phone http://www.piclist.com/member/JMN-EFP-786 PIC/PICList FAQ: http://www.piclist.com

On 4/3/06, William Chops Westfield <westfwEraseME.....mac.com> wrote: {Quote hidden}> > On Apr 3, 2006, at 11:25 AM, Robert Rolf wrote: > > >> I don't WANT to build one. > > > Like the many hacks based on the Linksys WRT54G routers, which are > > essentially running a linux kernal. > > > Yes, exactly! Although in that case I think only enough of the > official software is "open source" that people have been able > to replace it wholesale; A sort of "we didn't really mean for > this to be open source but we got caught by the GPL. Oops." > SW that was intended to be open source from the start would be > better. The situation with Tivo is probably a better example. > > Although - I think the official theory is that all other WRT54G > software is a "support nightmare." (note "theory" - I'm not sure > that this is true.) Newer versions of the box labeled WRT54G > have different HW, the official software is no longer linux based, > and the third-party images don't run. For which we were duly dinged > by the open source community. (though I can see both sides of THAT.) > They still sell the Linux-combatible version as "WRT54GL". So I guess they've learned quickly. Open firmware has made the WRT54G the most desirable consumer wireless router out there. It's the only one with a model number I've memorized, and with fan sites on the Internet. Someday I'm going to add wheels to one and make a Linux-powered robot. Regards, Mark markrages@gmail -- You think that it is a secret, but it never has been one. - fortune cookie

You mean the Electronics Bench in a Box? http://techref.massmind.org/techref/idea/ebb.htm On 4/3/06, James Newton, Host <EraseMEjamesnewtonpiclist.com> wrote: {Quote hidden}> > EXTREMELY unlikely. > > We collectively can't even agree on a PIC programmer design. > > The amount of expertise on this list is considerable, but > > with that comes a.. "diversity of opinion"... Yeah, that's > > the right word, I think. :-) > > Before anyone decides to try doing another "group project" PLEASE go to the > archive and read the threads on the last group design that was attempted on > the piclist. Search for CUMP or... What was the other one called? The > development kit thing? > > --- > James Newton: PICList webmaster/Admin > RemoveMEjamesnewtonEraseMEEraseMEpiclist.com 1-619-652-0593 phone > http://www.piclist.com/member/JMN-EFP-786 > PIC/PICList FAQ: http://www.piclist.com > > > -

I know what you mean. A PC. Don't like the OS, change it. I like TI calc for it's programming capabilities but the OS is off limits.... Maybe someone Just like my PalmIII. Such fine hardware without being able to do anything. John --- William Chops Westfield <RemoveMEwestfwspam_OUTKILLspammac.com> wrote: {Quote hidden}> > On Apr 3, 2006, at 9:55 AM, kravnus wolf wrote: > >> [open source Osilloscope] > > > Actually from the amount of members on the list > and the quality > > we have I am suprise we don't build one as a team. > Hint hint ;) > > I don't WANT to build one. That's *HARD*; high > precision analog > design is SCARY. What I want is to be able to take > a commercially > purchased unit and just TWEAK the software a little > bit so that it > ends up more like the way I want it to be... > > BillW > --

William Chops Westfield wrote: > Although - I think the official theory is that all other WRT54G > software is a "support nightmare." (note "theory" - I'm not sure > that this is true.) Newer versions of the box labeled WRT54G > have different HW, the official software is no longer linux based, > and the third-party images don't run. For which we were duly dinged > by the open source community. (though I can see both sides of THAT.) Linksys switched to the VxWorks RTOS on the later models of the WRT54G series routers, but understood that people who WANT to hack their routers wanted to Linux version, so they released the WRT54GL -- "L" for Linux. Nate

In message <EraseME20060404051059.36773.qmailspamspamBeGoneweb34303.mail.mud.yahoo.com>> kravnus wolf <RemoveMEkravnusKILLspamyahoo.com> wrote: > But the update through RS232 is not enough. But still > useful for low freq. sounds like a good idea. Is there > any place that sell this kind of portable cable? There used to be places that sold the Palm HotSync connectors, but I haven't seen any for a long while. I wanted a bare connector for my Palm VIIx so I could build up a few cables, but it looks like they're unobtainium now. -- Phil. | Kitsune: Acorn RiscPC SA202 64M+6G ViewFinder philpemSTOPspamspam_OUTdsl.pipex.com | Cheetah: Athlon64 3200+ A8VDeluxeV2 512M+100G http://www.philpem.me.uk/ | Tiger: Toshiba SatPro4600 Celeron700 256M+40G

On Apr 4, 2006, at 4:50 AM, Philip Pemberton wrote: >> Is there any place that sell this kind of portable cable? > > There used to be places that sold the Palm HotSync connectors, > but I haven't seen any for a long while. I wanted a bare connector > for my Palm VIIx so I could build up a few cables, but it looks > like they're unobtainium now. > PDA cables are distressingly one-of-a-kind, but I bought several of these to go with my old Palm IIIs: http://www.surpluscomputers.com/store/main.aspx? p=ItemDetail&item=ACC10692 There seems to be no end of add-on vendors that got "burnt" by the high turnover rate of the physical connectors (and stylus shape) of PDAs a couple of years back (things seem more settled now, I guess.) There are several places selling things like keypads for the Palm m100; I've seen prices down around $1.99: http://www.geeks.com/details.asp?invtid=TKB150P&cat=PDA BillW

On 4/4/06, William Chops Westfield <spamBeGonewestfwSTOPspamEraseMEmac.com> wrote: > > On Apr 4, 2006, at 5:09 AM, Gerhard Fiedler wrote: > > >> But the update through RS232 is not enough. > > > > I figure a screen update is about 160 bytes (cause the screen > is typically 160x160 pixles, so a 115200bps link would give you > better than 50Hz update, assuming the screen can even go that fast, > even without compression... 160 pixels * 160 pixels = 25600 pixels For a monochrome screen, 1 pixel == 1 bit 25600 / 8 = 3200 bytes per screen at 10 bits per byte RS232, 32000 bits per screen (Yes, this is more than the original resolution) at 115200 baud, 115200 / 32000 = 3.6Hz update If the pixels are not monochrome, multiply bits by color depth in pixels, and divide update by color depth in pixels. Bill -- Psst... Hey, you... Buddy... Want a kitten? straycatblues.petfinder.org

{Quote hidden}>-----Original Message----- >From: KILLspampiclist-bouncesspamBeGonemit.edu [EraseMEpiclist-bouncesEraseMEmit.edu] >Sent: 04 April 2006 14:08 >To: Microcontroller discussion list - Public. >Subject: Re: [EE] Oscilloscopes... > > >On 4/4/06, William Chops Westfield <@spam@westfw@spam@spam_OUTmac.com> wrote: >> >> On Apr 4, 2006, at 5:09 AM, Gerhard Fiedler wrote: >> >> >> But the update through RS232 is not enough. >> > >> >> I figure a screen update is about 160 bytes (cause the screen is >> typically 160x160 pixles, so a 115200bps link would give you better >> than 50Hz update, assuming the screen can even go that fast, even >> without compression... > >160 pixels * 160 pixels = 25600 pixels > >For a monochrome screen, 1 pixel == 1 bit > >25600 / 8 = 3200 bytes per screen > >at 10 bits per byte RS232, 32000 bits per screen >(Yes, this is more than the original resolution) > >at 115200 baud, 115200 / 32000 = 3.6Hz update > >If the pixels are not monochrome, multiply bits by color >depth in pixels, and divide update by color depth in >pixels. > >Bill But it's an oscilloscope, you don't want to display pictures so why not just send the cordinates of the data points? For a 160x160 screen that's a maximum of 160 bytes, less if you want to try and use the redundant bits. Regards Mike ======================================================================= This e-mail is intended for the person it is addressed to only. The information contained in it may be confidential and/or protected by law. If you are not the intended recipient of this message, you must not make any use of this information, or copy or show it to any person. Please contact us immediately to tell us that you have received this e-mail, and return the original to us. Any use, forwarding, printing or copying of this message is strictly prohibited. No part of this message can be considered a request for goods or services. =======================================================================

Michael Rigby-Jones wrote: {Quote hidden}> >>-----Original Message----- >>From: spamBeGonepiclist-bouncesKILLspammit.edu [.....piclist-bouncesspam_OUTmit.edu] >>Sent: 04 April 2006 14:08 >>To: Microcontroller discussion list - Public. >>Subject: Re: [EE] Oscilloscopes... >> >> >>On 4/4/06, William Chops Westfield <TakeThisOuTwestfw.....TakeThisOuTmac.com> wrote: >> >>>On Apr 4, 2006, at 5:09 AM, Gerhard Fiedler wrote: >>> >>> >>>>>But the update through RS232 is not enough. >>>> >>>I figure a screen update is about 160 bytes (cause the screen is >>>typically 160x160 pixles, so a 115200bps link would give you better >>>than 50Hz update, assuming the screen can even go that fast, even >>>without compression... >> >>160 pixels * 160 pixels = 25600 pixels >> >>For a monochrome screen, 1 pixel == 1 bit >> >>25600 / 8 = 3200 bytes per screen >> >>at 10 bits per byte RS232, 32000 bits per screen >>(Yes, this is more than the original resolution) >> >>at 115200 baud, 115200 / 32000 = 3.6Hz update >> >>If the pixels are not monochrome, multiply bits by color >>depth in pixels, and divide update by color depth in >>pixels. >> >>Bill > > > But it's an oscilloscope, you don't want to display pictures so why not just send the cordinates of the data points? For a 160x160 screen that's a maximum of 160 bytes, less if you want to try and use the redundant bits. You don't even need full coordinates. Just the sample values. Let the Palm(R) display software decide where to place them (scroll vs sweep vs average vs peak/envelope). Seems to me it would be dead easy to use a PIC with 8 bit A/D (since screen can't show more than 160 steps) to make this interface. Could do multi channel as well. R

On 4/4/06, William Couture <TakeThisOuTbcoutureKILLspamspamgmail.com> wrote: {Quote hidden}> On 4/4/06, William Chops Westfield <.....westfwRemoveMEmac.com> wrote: > > > > On Apr 4, 2006, at 5:09 AM, Gerhard Fiedler wrote: > > > > >> But the update through RS232 is not enough. > > > > > > > I figure a screen update is about 160 bytes (cause the screen > > is typically 160x160 pixles, so a 115200bps link would give you > > better than 50Hz update, assuming the screen can even go that fast, > > even without compression... > > 160 pixels * 160 pixels = 25600 pixels > > For a monochrome screen, 1 pixel == 1 bit > > 25600 / 8 = 3200 bytes per screen > > at 10 bits per byte RS232, 32000 bits per screen > (Yes, this is more than the original resolution) > > at 115200 baud, 115200 / 32000 = 3.6Hz update > > If the pixels are not monochrome, multiply bits by color > depth in pixels, and divide update by color depth in > pixels. > > Bill That's assuming that you want to be able to display any old bitmap you want. If just a line is sufficient, you only need to send one value - the Y coordinate - for each column of pixels. Thus, 160 bytes / frame. -- -Randy Glenn Computer Eng. and Mgt. Year IV, McMaster University Regional Student Representative, IEEE Canada randy.glenn-at-gmail.com - glennrb-at-mcmaster.ca randy.glenn-at-computer.org - randy_glenn-at-ieee.org http://www.randyglenn.ca

In message <RemoveME88eca9220604041418h57c691f8s3c58ff64594a4fd8spamBeGonemail.gmail.com>> "Mike Hord" <spamBeGonemike.hord@spam@spam_OUTgmail.com> wrote: > Funny you mention that. Xilinx has an Appnote on their > website about making a portable o-scope with an older > Handspring Visor using the Insight Springboard Dev Kit. Wasn't it a logic analyser, not an oscilloscope? I've just been reading through the appnote - it looks pretty nifty. Certainly a few neat ideas worth borrowing. > If you can find the dev kit, the Visors are pretty cheap now. > > I'm on the lookout for one, now that I know what I can do > with it...I have the Visor, just need the dev kit. I've got a Palm VIIx here, and I'm looking for a good Palm OS programming tutorial. I've got PODS and Cygwin installed, it's just a case of figuring out how to actually write some software with it :) Thanks. -- Phil. | Kitsune: Acorn RiscPC SA202 64M+6G ViewFinder TakeThisOuTphilpemspamdsl.pipex.com | Cheetah: Athlon64 3200+ A8VDeluxeV2 512M+100G http://www.philpem.me.uk/ | Tiger: Toshiba SatPro4600 Celeron700 256M+40G

Yes and no. Here are three links of pertinence: direct.xilinx.com/bvdocs/appnotes/xapp146.pdf 8 channel digital voltmeter. direct.xilinx.com/bvdocs/appnotes/xapp149.pdf Oscilloscope. direct.xilinx.com/bvdocs/appnotes/xapp368.pdf Logic analyzer. They also have a few other neat projects. If I could only find the dev kit! Mike H. On 4/4/06, Philip Pemberton <@spam@philpemRemoveMEEraseMEdsl.pipex.com> wrote: {Quote hidden}> In message <EraseME88eca9220604041418h57c691f8s3c58ff64594a4fd8@spam@mail.gmail.com>> > "Mike Hord" <@spam@mike.hordspam_OUT.....gmail.com> wrote: > > > Funny you mention that. Xilinx has an Appnote on their > > website about making a portable o-scope with an older > > Handspring Visor using the Insight Springboard Dev Kit. > > Wasn't it a logic analyser, not an oscilloscope? > I've just been reading through the appnote - it looks pretty nifty. Certainly > a few neat ideas worth borrowing. > > > If you can find the dev kit, the Visors are pretty cheap now. > > > > I'm on the lookout for one, now that I know what I can do > > with it...I have the Visor, just need the dev kit. > > I've got a Palm VIIx here, and I'm looking for a good Palm OS programming > tutorial. I've got PODS and Cygwin installed, it's just a case of figuring > out how to actually write some software with it :) > > Thanks. > -- > Phil. | Kitsune: Acorn RiscPC SA202 64M+6G ViewFinder > spamBeGonephilpemEraseMEdsl.pipex.com | Cheetah: Athlon64 3200+ A8VDeluxeV2 512M+100G > http://www.philpem.me.uk/ | Tiger: Toshiba SatPro4600 Celeron700 256M+40G > -