Post by thread:[PIC] SD/MMC Interface to PIC18F using PBasicPro

part 1 407 bytes content-type:text/plain; charset=ISO-8859-1; format=flowed (decoded 7bit) I have an existing client with a data logger product who would like to add SD/MMC storage to the unit. The project was originally written in PBPro, some 300+ lines of code. How feasable would it be to add an SD/MMC interface. The SD/MMC card will be used to dump data to a PC at a later stage. The CPU is a PIC18F452, a PC18F4520 may be substituted. Thanks. Nino. part 2 373 bytes content-type:text/x-vcard; charset=utf-8; name=Nino.Benci.vcf (decoded 7bit) begin:vcard fn:Antonio L. Benci n:Benci;Antonio L. org:Monash University;School of Physics adr:;;;Monash University;VIC;3800;Australia email;internet:spam_OUTelectronic.servicesTakeThisOuTspme.monash.edu.au title:Professional Officer tel;work:+613 9905 3649 tel;fax:+613 9905 3637 x-mozilla-html:FALSE url:http://spme.monash.edu.au version:2.1 end:vcard part 3 35 bytes content-type:text/plain; charset="us-ascii" (decoded 7bit)

> I have an existing client with a data logger product who would like to > add SD/MMC storage to the unit. The project was originally written in > PBPro, some 300+ lines of code. Are you wanting to add it in PBP or assembly or something else? PBP is extremely easy to use and pretty useful; you can also just write inline assembly using the ASM...ENDASM directive. > How feasable would it be to add an SD/MMC interface. The SD/MMC card > will be used to dump data to a PC at a later stage. The CPU is a > PIC18F452, a PC18F4520 may be substituted. I'm actually thinking about a similar enhancement for a datalogger I'm working on. It's a little more complicated for mine, since it has to be watertight which means we'd need to change the chassis to make the card easy to remove. What's stopping me (aside from that) is that to be PC readable, you'd need to put the files on the card in FAT format. Which, AIUI, implies that you need Microsoft's blessing, since they are the patent holder on FAT. IANAL, and if anyone (preferably a lawyer familiar with the situation) can shed some light upon it, I'd appreciate it. Mike H.

AFAIK Microsoft only holds a patent on a detail of storing long filenames on FAT. Not FAT itself. Marcel Mike Hord wrote: {Quote hidden}>> I have an existing client with a data logger product who would like to >> add SD/MMC storage to the unit. The project was originally written in >> PBPro, some 300+ lines of code. > > Are you wanting to add it in PBP or assembly or something else? > PBP is extremely easy to use and pretty useful; you can also just > write inline assembly using the ASM...ENDASM directive. > >> How feasable would it be to add an SD/MMC interface. The SD/MMC card >> will be used to dump data to a PC at a later stage. The CPU is a >> PIC18F452, a PC18F4520 may be substituted. > > I'm actually thinking about a similar enhancement for a datalogger I'm > working on. It's a little more complicated for mine, since it has to be > watertight which means we'd need to change the chassis to make the > card easy to remove. What's stopping me (aside from that) is that to > be PC readable, you'd need to put the files on the card in FAT format. > Which, AIUI, implies that you need Microsoft's blessing, since they > are the patent holder on FAT. > > IANAL, and if anyone (preferably a lawyer familiar with the situation) > can shed some light upon it, I'd appreciate it. > > Mike H.

part 1 1702 bytes content-type:text/plain; charset=ISO-8859-1; format=flowed (decoded 7bit) I will need to write the data in FAT format so that the PC can easily read the card. Nino. Marcel van Lieshout wrote: {Quote hidden}> AFAIK Microsoft only holds a patent on a detail of storing long > filenames on FAT. Not FAT itself. > > Marcel > > Mike Hord wrote: > >>> I have an existing client with a data logger product who would like to >>> add SD/MMC storage to the unit. The project was originally written in >>> PBPro, some 300+ lines of code. >> >> >> Are you wanting to add it in PBP or assembly or something else? >> PBP is extremely easy to use and pretty useful; you can also just >> write inline assembly using the ASM...ENDASM directive. >> >>> How feasable would it be to add an SD/MMC interface. The SD/MMC card >>> will be used to dump data to a PC at a later stage. The CPU is a >>> PIC18F452, a PC18F4520 may be substituted. >> >> >> I'm actually thinking about a similar enhancement for a datalogger I'm >> working on. It's a little more complicated for mine, since it has to be >> watertight which means we'd need to change the chassis to make the >> card easy to remove. What's stopping me (aside from that) is that to >> be PC readable, you'd need to put the files on the card in FAT format. >> Which, AIUI, implies that you need Microsoft's blessing, since they >> are the patent holder on FAT. >> >> IANAL, and if anyone (preferably a lawyer familiar with the situation) >> can shed some light upon it, I'd appreciate it. >> >> Mike H. > > part 2 373 bytes content-type:text/x-vcard; charset=utf-8; name=Nino.Benci.vcf (decoded 7bit) begin:vcard fn:Antonio L. Benci n:Benci;Antonio L. org:Monash University;School of Physics adr:;;;Monash University;VIC;3800;Australia email;internet:.....electronic.servicesKILLspam@spam@spme.monash.edu.au title:Professional Officer tel;work:+613 9905 3649 tel;fax:+613 9905 3637 x-mozilla-html:FALSE url:http://spme.monash.edu.au version:2.1 end:vcard part 3 35 bytes content-type:text/plain; charset="us-ascii" (decoded 7bit)

>I will need to write the data in FAT format so that the >PC can easily read the card. Get the definitive document of coding for the FAT format from Microsoft. It provides code segments in "pseudo C" and provides lots of hints on how to and what not to do in dealing with the format, and why some implementations short cuts are not the correct way to deal with the format. The copy I have is Rev 1.03, and the filename is fatgen103.pdf. what looks like a more recent release of the same document as a Word file is available here http://www.microsoft.com/whdc/system/platform/firmware/fatgen.mspx