Post by thread:[PIC] LARGE capacity MEMORY for picf876 project

On Tue, 2004-12-07 at 16:22 -0800, josh migeri wrote: > Dear all > Could someone plse advise me on where I can get LARGE capacity memory chips > to interface with a picf876. The project is to log rs232 data (lots of it), > off line, and then download it to a PC later. Is this project for volume? If not I'd suggest just getting a common flash card. I used a compact flash card in my carmon project (which does exactly what you're talking about): http://repatch.dyndns.org:8383/pic_stuff/carmon If I were to do it again I would have used an SD card instead (SPI interface, much simpler) and an 18F or 30F part (therefore no need for the external EEPROM). TTYL ----------------------------- Herbert's PIC Stuff: http://repatch.dyndns.org:8383/pic_stuff/ ____________________________________________

>Could someone plse advise me on where I can get >LARGE capacity memory chips to interface with a >picf876. The project is to log rs232 data (lots >of it), off line, and then download it to a PC later. Is the PCB already laid out? If not then it sounds like you should look at some of the top end 18F chips, as they have more internal RAM. If it is already laid out then look at one of the compatable pinout 18F series. Either way, without knowing just how much memory you need, you are probably looking at needing ramtron I2C or SPI compatible chips for of-processor storage. ____________________________________________

Define 'LARGE'? There are 512 kb eeproms available and Ramtron has FRAMS that are bigger than that (1024kb for sure and I think 2048kb) bigger than that I'd probably recommend a flash memory card like they use for digital cameras. Check the archives, there's been a couple projects using those discussed here. (Herbert Graf's Carmon project comes to mind http://repatch.dyndns.org:8383/pic_stuff/carmon/index.html) -Denny > > Dear all > Could someone plse advise me on where I can get LARGE capacity memory chips > to interface with a picf876. The project is to log rs232 data (lots of it), > off line, and then download it to a PC later. > > Kindest regards > > Josh Migeri > > ______________________________________________

Does anyone know if the new USB pics have the ability act as a host? The cheap usb flash drives that you can now pick up in your drugstore checkout line would be perfect for this sort of thing. Regards, Bob On Tue, 7 Dec 2004 08:06:22 -0800, William Chops Westfield <spam_OUTwestfwTakeThisOuTmac.com> wrote: {Quote hidden}> On Dec 7, 2004, at 4:22 PM, josh migeri wrote: > > > Could someone plse advise me on where I can get LARGE capacity memory > > chips > > to interface with a picf876. The project is to log rs232 data (lots of > > it), > > off line, and then download it to a PC later. > > > MMC or SD "flash cards" seem to be the common solution for that sort of > thing. > > BillW > > > > ______________________________________________

some folk have had great success using MMC or SD data cards mounted on-pcb, and interfaced to the PIC using regular SPI. Using this method you can provide 512Mb or more of ram using just one component. (well, two if you count the card's socket) The MMC/SD approach also means that you can remove the card, and load it into a PC for examination (so long as you use the standard FAT file format) Peter Moreton > {Original Message removed}

On Tue, 2004-12-07 at 12:26 -0500, Bob J wrote: > Does anyone know if the new USB pics have the ability act as a host? > > The cheap usb flash drives that you can now pick up in your drugstore > checkout line would be perfect for this sort of thing. They only can act as slaves. TTYL ----------------------------- Herbert's PIC Stuff: http://repatch.dyndns.org:8383/pic_stuff/ ____________________________________________

hmmm, wonder if usb-on-the-go is viable. I haven't heard much on this subject. See http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822 Regards, Bob On Tue, 07 Dec 2004 12:49:13 -0500, Herbert Graf <.....mailinglist2KILLspam@spam@farcite.net> wrote: {Quote hidden}> On Tue, 2004-12-07 at 12:26 -0500, Bob J wrote: > > Does anyone know if the new USB pics have the ability act as a host? > > > > The cheap usb flash drives that you can now pick up in your drugstore > > checkout line would be perfect for this sort of thing. > > They only can act as slaves. TTYL > > > ----------------------------- > Herbert's PIC Stuff: > http://repatch.dyndns.org:8383/pic_stuff/ > > _______________________________________________ > >

At 01:26 PM 12/7/2004 -0500, you wrote: >hmmm, wonder if usb-on-the-go is viable. I haven't heard much on this >subject. > >See http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822 > >Regards, >Bob Philips has (have) some processor chips that support it. Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" speffKILLspaminterlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com ____________________________________________

On Tue, 2004-12-07 at 13:26 -0500, Bob J wrote: > hmmm, wonder if usb-on-the-go is viable. I haven't heard much on this subject. > > See http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822 Not with the USB peripheral in the PIC, unless the "slave" you connect to can act as host. TTYL ----------------------------- Herbert's PIC Stuff: http://repatch.dyndns.org:8383/pic_stuff/ ____________________________________________

The easiest to use is MMC and/or SD modules, as they can be interfaced easily with the SPI port. I've seem up to 512MB modules sold already as FAT12. The only issue is that you will need a small 512b buffer, so I'd use a small SPI RAMTRON as temporary storage. With the PIC18F, you won't even need the RAMTRON. --Bob josh migeri wrote: >Dear all >Could someone plse advise me on where I can get LARGE capacity memory chips >to interface with a picf876. The project is to log rs232 data (lots of it), >off line, and then download it to a PC later. > >Kindest regards > >Josh Migeri > >_____________________________________________

Using a FAT formatted data card is great, however I'm not sure its entirely legal (at least without giving Microsoft some royalties). I was thinking about using a FAT formatted card on a design recently (and offering the source code) however I found the following information at: http://www.microsoft.com/mscorp/ip/tech/fat.asp //*********************************************** A license for manufacturers of certain consumer electronics devices. Pricing for this license is US$0.25 per unit for each of the following types of devices that use removable solid state media to store data: portable digital still cameras; portable digital video cameras; portable digital still/video cameras; portable digital audio players; portable digital video players; portable digital audio/video players; multifunction printers; electronic photo frames; electronic musical instruments; and standard televisions. Pricing for this license is US$0.25 per unit with a cap on total royalties of $250,000 per licensee. Pricing for other device types can be negotiated with Microsoft. //*********************************************** Along with the other info on that page it appears you can't design a product using FAT even if the card is already formatted. Someone, please tell me I'm wrong (and why)! Ken .....klumiaKILLspam.....adelphia.net {Original Message removed}

From: "Peter Moreton" <EraseMEpeter.moretonspam_OUTTakeThisOuTvirgin.net> > some folk have had great success using MMC or SD data cards > mounted on-pcb, and interfaced to the PIC using regular SPI. > Using this method you can provide 512Mb or more of ram using > just one component. (well, two if you count the card's socket) > > The MMC/SD approach also means that you can remove the card, > and load it into a PC for examination (so long as you use > the standard FAT file format) > > Peter Moreton I have a few extra SD cards laying around, and after hearing this (lightbulb!) I'd like to find some PCB-mount sockets to fit them in to try this out. Does anybody know an easy supplier? Are there any gotcha's about the socket designs or compatibilities I should know about? (it seems there are always some gotchas) Thanks in advance, Robert B. ____________________________________________

On Tue, 2004-12-07 at 12:24 -0700, Bob Axtell wrote: > The easiest to use is MMC and/or SD modules, as they can be interfaced > easily with the SPI port. > I've seem up to 512MB modules sold already as FAT12. The only issue is > that you will need a small > 512b buffer, so I'd use a small SPI RAMTRON as temporary storage. > > With the PIC18F, you won't even need the RAMTRON. Actually, depending on how you do things, you don't even need 512 bytes of local storage, you can just write to the SD card as you get data. It's not the way I did it, but if you can live with the limitations it is a viable option. TTYL ----------------------------- Herbert's PIC Stuff: http://repatch.dyndns.org:8383/pic_stuff/ ____________________________________________

www.pubpat.org/Microsoft_517_Rejected.htm Regards, Mark markrages@gmail On Tue, 7 Dec 2004 14:49:35 -0500, Kenneth Lumia <klumiaspam_OUTadelphia.net> wrote: {Quote hidden}> Using a FAT formatted data card is great, however I'm not sure its > entirely legal (at least without giving Microsoft some royalties). > I was thinking about using a FAT formatted card on a design > recently (and offering the source code) however I found the > following information at: > > www.microsoft.com/mscorp/ip/tech/fat.asp > > //*********************************************** > A license for manufacturers of certain consumer electronics > devices. Pricing for this license is US$0.25 per unit for each > of the following types of devices that use removable solid state > media to store data: portable digital still cameras; portable digital > video cameras; portable digital still/video cameras; portable > digital audio players; portable digital video players; portable > digital audio/video players; multifunction printers; electronic > photo frames; electronic musical instruments; and standard > televisions. Pricing for this license is US$0.25 per unit with a > cap on total royalties of $250,000 per licensee. Pricing for > other device types can be negotiated with Microsoft. > //*********************************************** > > Along with the other info on that page it appears you can't > design a product using FAT even if the card is already > formatted. > > Someone, please tell me I'm wrong (and why)! > > Ken > @spam@klumiaKILLspamadelphia.net > > > > > {Original Message removed}

On Tue, 2004-12-07 at 14:49 -0500, Kenneth Lumia wrote: > Using a FAT formatted data card is great, however I'm not sure its > entirely legal (at least without giving Microsoft some royalties). > I was thinking about using a FAT formatted card on a design > recently (and offering the source code) however I found the > following information at: Actually that is a perfect example of how abused the patent system is these days. No worries though, IIRC there was so much prior art present that the patent office reversed the patent. TTYL ----------------------------- Herbert's PIC Stuff: http://repatch.dyndns.org:8383/pic_stuff/ ____________________________________________

That's new to me. My documentation seemed clear, to me, it needed a burst. How does one do that- just don't send the 8 SPI clocks/data until the data is ready to be sent? holding the CS line down the who;le time? Interesting approach, actually that MIGHT work. Herb, is that how you mean? I gotta dig into my SanDisk SD book again. --Bob Herbert Graf wrote: {Quote hidden}>On Tue, 2004-12-07 at 12:24 -0700, Bob Axtell wrote: > > >>The easiest to use is MMC and/or SD modules, as they can be interfaced >>easily with the SPI port. >>I've seem up to 512MB modules sold already as FAT12. The only issue is >>that you will need a small >>512b buffer, so I'd use a small SPI RAMTRON as temporary storage. >> >>With the PIC18F, you won't even need the RAMTRON. >> >> > >Actually, depending on how you do things, you don't even need 512 bytes >of local storage, you can just write to the SD card as you get data. >It's not the way I did it, but if you can live with the limitations it >is a viable option. TTYL > >----------------------------- >Herbert's PIC Stuff: >http://repatch.dyndns.org:8383/pic_stuff/ > >_____________________________________________

On Tue, 2004-12-07 at 13:47 -0700, Bob Axtell wrote: > That's new to me. My documentation seemed clear, to me, it needed a > burst. How does > one do that- just don't send the 8 SPI clocks/data until the data is > ready to be sent? holding > the CS line down the who;le time? Interesting approach, actually that > MIGHT work. > > Herb, is that how you mean? I gotta dig into my SanDisk SD book again. Of course. SPI is a synchronous protocol. There is no definition of "burst" outside of the clock you feed the client. Now, there are SPI devices out there that probably spec a minimum clock period, but all the card specs I've see allow you do go down to pretty much DC. TTYL ----------------------------- Herbert's PIC Stuff: http://repatch.dyndns.org:8383/pic_stuff/ ____________________________________________

Herbert Graf wrote: {Quote hidden}>On Tue, 2004-12-07 at 12:24 -0700, Bob Axtell wrote: > > >>The easiest to use is MMC and/or SD modules, as they can be interfaced >>easily with the SPI port. >>I've seem up to 512MB modules sold already as FAT12. The only issue is >>that you will need a small >>512b buffer, so I'd use a small SPI RAMTRON as temporary storage. >> >>With the PIC18F, you won't even need the RAMTRON. >> >> > >Actually, depending on how you do things, you don't even need 512 bytes >of local storage, you can just write to the SD card as you get data. >It's not the way I did it, but if you can live with the limitations it >is a viable option. TTYL > > what limitations ? And if your incoming data is slow enough, you could perform a readblock-modify1byte-writeblock, without storing the complete block into memory. Stef Mientki > > ____________________________________________

On Tue, 2004-12-07 at 22:32 +0100, Stef Mientki wrote: {Quote hidden}> > Herbert Graf wrote: > > >On Tue, 2004-12-07 at 12:24 -0700, Bob Axtell wrote: > > > > > >>The easiest to use is MMC and/or SD modules, as they can be interfaced > >>easily with the SPI port. > >>I've seem up to 512MB modules sold already as FAT12. The only issue is > >>that you will need a small > >>512b buffer, so I'd use a small SPI RAMTRON as temporary storage. > >> > >>With the PIC18F, you won't even need the RAMTRON. > >> > >> > > > >Actually, depending on how you do things, you don't even need 512 bytes > >of local storage, you can just write to the SD card as you get data. > >It's not the way I did it, but if you can live with the limitations it > >is a viable option. TTYL > > > > > what limitations ? > > And if your incoming data is slow enough, you could perform a > readblock-modify1byte-writeblock, > without storing the complete block into memory. > > Stef Mientki The main limitations I can think of off hand is you can't "modify" a sector (512Byte chunk). This isn't important if you're just writing data to the card in a simple manner (i.e. the way i do it by having one huge file on the disk and using other means to determine where writing to that file stopped). However, if you have to modify sectors (i.e. if you intend to use the FAT file system to it's fullest) you will require local storage. For example, if you need to update the FAT chain for the file you are working on you have to traverse the chain (to find it's end), modify the last entry to point to the next entry, and modify the new end entry. This requires reading in a sector, modding a few bytes, and then writing it out again. For something like this you require local storage of one sector (512 bytes). There are also other examples (i.e. modding the directory entry for file size for the file you're working on, adding a directory entry) that require modding a sector. TTYL ----------------------------- Herbert's PIC Stuff: http://repatch.dyndns.org:8383/pic_stuff/ ____________________________________________