Post by thread:[EE] Looking for inexpensive serial logger

Hi, I'm looking for an inexpensive logger for serial data. Required function is very simple: stores what comes in, lets me retrieve later what got stored. Purpose is to replace a notebook PC for logging what comes out of a standard serial port while in the field. (Gets shaken quite a bit.) Pretty much anything that fits the above would be fine, of course the more memory (1 MB would be fine) and the faster the interface (currently 115.2 kbps) the better. Thanks for any pointers, Gerhard

Have a look at the 'Windmill' data logging software. They offer a free version. Have downloaded but not tried it. No idea if it's what you want. See: http://www.windmill.co.uk/ Regards Roland At 01:21 PM 08/09/2005 -0300, you wrote: {Quote hidden}>Hi, > >I'm looking for an inexpensive logger for serial data. Required function is >very simple: stores what comes in, lets me retrieve later what got stored. >Purpose is to replace a notebook PC for logging what comes out of a >standard serial port while in the field. (Gets shaken quite a bit.) > >Pretty much anything that fits the above would be fine, of course the more >memory (1 MB would be fine) and the faster the interface (currently 115.2 >kbps) the better. > >Thanks for any pointers, >Gerhard >-

Roland wrote: >> I'm looking for an inexpensive logger for serial data. Required function >> is very simple: stores what comes in, lets me retrieve later what got >> stored. Purpose is to replace a notebook PC for logging what comes out >> of a standard serial port while in the field. (Gets shaken quite a >> bit.) > Have a look at the 'Windmill' data logging software. They offer a free > version. Have downloaded but not tried it. No idea if it's what you > want. > > See: http://www.windmill.co.uk/ Thanks for the pointer... But maybe I wasn't clear enough: I'm looking for a /hardware/ device with a serial interface to replace the notebook PC that we are using now. (We have already a suitable serial communication software that logs what we need.) I may even consider a kit, if the price is right. This is what I've found so far: - http://homepages.tig.com.au/~robk/serial/price_all.htm: $300. This is pretty much what I have in mind. Just maybe something still more inexpensive, and possibly in the USA (less shipping cost). So far it's the only one in this category that I found. Can it be that there is no other device like that out there? - http://www.acumeninstruments.com/Products/SDR-CF/SDR-CF.shtml: $570 + memory card. This is a bit more than I'm asking for, both in features and price. - http://www.cyberdata.net/products/test/serialdatalogger.html: Price and availability not known. - http://www.sanpeople.com/products/baseline.asp: Price not known, but looks expensive. For my application, the network interface for extracting the logged data is not even helpful. Thanks, Gerhard

On Sep 8, 2005, at 12:25 PM, Gerhard Fiedler wrote: > I'm looking for a /hardware/ device with a serial interface to > replace the notebook PC that we are using now. Traditionally, logging serial data at 115200bps to anything other than ram is relatively difficult. There's not a lot that can be done in the less than 100 us between characters, and most "storage" code isn't very happy being interrupted every 100us either. Windows "solves" this problem by demanding uarts with deep HW fifos... BillW

On 8 Sep 2005 at 15:21, Chops wrote: > On Sep 8, 2005, at 12:25 PM, Gerhard Fiedler wrote: > > > I'm looking for a /hardware/ device with a serial interface to > > replace the notebook PC that we are using now. > > Traditionally, logging serial data at 115200bps to anything other > than ram is relatively difficult. There's not a lot that can be > done in the less than 100 us between characters, and most "storage" > code isn't very happy being interrupted every 100us either. Windows > "solves" this problem by demanding uarts with deep HW fifos... > Asynchronous 115200 bits per second is 11520 bytes per second. It could be stored in uP RAM and SPIed to a SD-card memory, 512 bytes each time. I'm currently working on a project for a client using an Atmel ATmega8 to do that kind of thing. Mark Jordan

William ChopsWestfield wrote: >> I'm looking for a /hardware/ device with a serial interface to >> replace the notebook PC that we are using now. > > Traditionally, logging serial data at 115200bps to anything other > than ram is relatively difficult. This is not a continuous 115.2kbps data stream. The data rate averaged over a few seconds is probably less than 500 bytes per second. With a few k of buffer RAM Flash storage should be possible. > most "storage" code isn't very happy being interrupted every 100us > either. Why is that? I never had problems with my storage code being interrupted... Usually it is not a problem checking back a bit later. Gerhard

Do you not want to make one ? Would be fairly simple. An 18F452 would be ideal. It has the UART, TMR1 for time- tamping (could be relative or TOD) and enough I/O to directly address a big SRAM without driver ICs (eg 4040), with the addition of a selector (eg 74138) memory can be increased by paralleling. Sessions would be made identifiable quite easily with a generated file-name

On Sep 8, 2005, at 5:36 PM, Gerhard Fiedler wrote: >> Traditionally, logging serial data at 115200bps to anything other >> than ram is relatively difficult. > > This is not a continuous 115.2kbps data stream. The data rate averaged > over > a few seconds is probably less than 500 bytes per second. With a few k > of > buffer RAM Flash storage should be possible Should be... > >> most "storage" code isn't very happy being interrupted every 100us >> either. > > Why is that? I never had problems with my storage code being > interrupted... > Usually it is not a problem checking back a bit later. > I think it's because turning off interrupts is the easiest way of ensuring exclusive access to a resource that you're quite sure is not reentrant. For instance, if you start that block write to the flash or floppy, you sure don't want anything else coming in and trying to use the flash/floppy while you are doing so. The easiest way to do that is to sit there in a busy loop with interrupts disabled. Sure, with a little discipline and some systems design, you can guarantee and trust that your serial driver will never touch your flash memory, but frequently that discipline is lacking. Long ago I worked on a serial data logger for DOS (to floppy, IIRC.) What a PITA that was. The serial code wanted to initiate a write to floppy from the ISR (after all, not multithreading or multiprocessing in DOS above the ISR level), but went through hoops trying to ensure that it didn't do so if the foreground DOS program was already withing a DOS system call of any kind (all of which has rather unpredictable characteristics WRT reentancy!) BillW

Jinx wrote: > Do you not want to make one ? Would be fairly simple. Yes, and for a brief moment I thought about it. But to get it into a useful form would take some time -- and it seems that a used PDA with serial adapter can be had for a price that's hard to compete with... The price of NVSRAM is more than a used PDA :) (Of course I don't have to use NVSRAM, but just to make a point.) Gerhard

> > Do you not want to make one ? Would be fairly simple. > > Yes, and for a brief moment I thought about it. But to get > it into a useful form would take some time -- and it seems > that a used PDA with serial adapter can be had for a price > that's hard to compete with Yeah, I know. Cheap stuff kinda takes the fun out of knowing how to make things sometimes. Then again, if you did make your own you could spiff it up. Include analogue sampling for example, have it any colour you wanted.........

Mark Scoville wrote: > Gerhard, might this be of interest? > > http://homepages.tig.com.au/~robk/serial/ Yes, thanks. That's the one I also found :) (listed in another email with this subject, together wit a few others). But it seems that a PDA (used, or even a cheap new one) with a serial adapter fits my needs and adds a few features that such a black-box logger doesn't have (like being able to watch the log, either while being logged or at least after stopping the logging, and being able to interact and issue some commands). Gerhard

Jinx wrote: >> it seems that a used PDA with serial adapter can be had for a price >> that's hard to compete with > > Yeah, I know. Cheap stuff kinda takes the fun out of knowing how to make > things sometimes. In a way... but to me most of the fun is in finding out how exactly to do stuff, and then of course in using the final thing. The part in between is where I need to motivate myself :) This is a facet of my personality that sometimes complicates things for me (here we come back to the money factor that Dmitriy brought up in another context :) Gerhard

Anand Dhuru wrote: > You might find some very interesting solutions here > http://www.sirpic.com/index.html Thanks, that's indeed interesting -- but it seems not to be suitable for my application. The main restrictions are that the log is limited to 32k and that the user seems to have to store the log manually every 32k. Both restrictions make this unsuitable for my application. Besides this it seems inconvenient that the log gets stored (and transferred to the PC) as memo items, with 4k max each. However, using the PDA's IR port for logging is a cool feature. Gerhard

MarcoG wrote: > Try this: tourviewer.sourceforge.net/filexfer.html > > It is free. Seems tah you cannot watch to the incoming data, but only when > it is sent to the PC. Thanks. It seems that even though a PDA looks like a pretty useful field interface, and many of the Palm devices come with a serial port built in, there is no real terminal software on the market. At least I've not yet seen one... Currently I'm waiting for feedback from John Pearson -- he has something that's at least pretty close to a terminal program. But it's for the PPC platform, not the Palm. Gerhard

Gerhard wrote: >>It seems that even though a PDA looks like a pretty useful >> field interface, and many of the Palm devices come with a >> serial port built in, there is no real terminal software >> on the market. At least I've not yet > seen one... not exactly.. For Palm there is Online, a Terminal program that has many of the features that you need for logging and viewing data: but isn't free (35$) http://www.conklinsystems.com/palm/online.php Instead, for those that don't want get money and can acccept more limitations, there is another interesting free program for Palm: http://netpage.em.com.br/mmand/ptelnet.htm It splits the incoming data in many 4k chunks, so isn't very practical for long files received. regards Marco

marco.genovesi@libero.it wrote: >>> It seems that even though a PDA looks like a pretty useful field >>> interface, and many of the Palm devices come with a serial port built >>> in, there is no real terminal software on the market. At least I've >>> not yet seen one... > For Palm there is Online, [...] > there is another interesting free program for Palm: [...] Very cool, thanks. It seems that the HotSync support on the Palm platform is more difficult to deal with than on the PPC platform, which results in those Palm programs writing to the memos limited to 4k rather than to a "normal" file. Gerhard