Perhaps you can use a USB flash drive instead of an SD card. The PIC will need to be an MSD host for this. Flash drives can be very small today and they will take care of buffering, wear leveling and writing to the internal flash. And you can easily move it to a PC when you want to transfer the files. /Ruben On Thu, 12 May 2016 18:20:44 -0400, Neil wrote: > I do (as always) have space limitations, and need to be able to move the= =20 > card to a PC to retrieve the files, so would actually use a micro=20 > SDHC. I won't need more than 4GB anyway. >=20 > Cheers, > -Neil. >=20 >=20 >=20 > On 5/12/2016 4:57 PM, James Burkart wrote: >> Thanks Neil! >> >> If you're not limited by size you might want to consider writing to a >> Compact Flash card. I don't believe there are any licensing issues and i= t's >> a parallel interface. For me CF is just a little too big. >> >> -- >> Sincerely, >> >> James Burkart >> *Filmmaker & Documentarian* >> >> *Burkart Studios* >> 415.738.2071 | Phone >> 925.226.4910 | Fax >> >> *Web:* burkartstudios.com >> *Facebook:* facebook.com/burkartstudios >> >> On Thu, May 12, 2016 at 2:46 PM, Neil wrote: >> >>> James, >>> >>> I've also been concerned about the SD data rate for a data-logging >>> device that I'm slowly working on, as I'm expecting to capture data jus= t >>> a bit above the max rate of the SD card. But I really want the data to >>> be on a removable data card, so I'm considering circular-buffering the >>> data to a RAM chip, and streaming that out to the SD card at the lower >>> rate. With the 4GB SD limit, I won't need 4GB of RAM, but I've ballpar= k >>> calculated I'd need just under 1 GB of RAM. Just need to figure out th= e >>> lowest cost option for the RAM. The values in RAM would be raw, then in >>> FAT32 format only when it's on the SD. >>> >>> I'll also consider compressing the data as it may help eliminate the >>> need for the buffer RAM.. >>> >>> As for the FAT32 4GB limit, I'm pretty sure the next level (exFAT IIRC) >>> is proprietary/closed/expensive, so perhaps format the SD card into >>> multiple 4GB partitions with the partitions labelled so you can get the= m >>> back in order? This would depend on how you plan to retrieve them. >>> >>> Cheers, >>> -Neil. >>> >>> >>> >>> >>> On 5/12/2016 4:31 AM, James Burkart wrote: >>>> I aspire to make a small audio recorder. I need to decide how and on w= hat >>>> it will record on, and how I will retrieve the files. >>>> >>>> I was originally considering having it record to microSD. Initial >>> obstacles >>>> I found were speed limitations from using SPI, and the FAT32 drivers I >>> was >>>> looking into will only access up to 4GB. >>>> >>>> FAT Driver I am reading up on. >>>> * >>> http://www.embedded-code.com/source-code/memory/secure-digital-mmc-memo= ry-cards/secure-digital-mmc-memory-card-fat16-fat32-driver >>>> < >>> http://www.embedded-code.com/source-code/memory/secure-digital-mmc-memo= ry-cards/secure-digital-mmc-memory-card-fat16-fat32-driver >>>> * >>>> >>>> Alternatively I was considering having the recorder write to flash mem= ory >>>> and then retrieving the files via USB interface. I know next to nothin= g >>>> about attempting this method. Immediate obstacles for me would be >>> figuring >>>> out the whole USB thing, and finding/writing FAT32 drivers for use wit= h >>> the >>>> flash memory (or do I?). >>>> >>>> USB stuff I have found. >>>> *http://www.signal11.us/oss/m-stack >>> * >>>> >>>> I would appreciate any thoughts or input, suggestions, sources to read= , >>>> what to consider, etc... >>>> What questions should I be asking myself? >>>> >>>> Note: I would like to be able to record stereo 48kHz/24-bit but I will >>>> settle on mono 44.1kHz/16-bit. >>>> >>>> -- >>>> James Burkart >>> -- >>> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >>> View/change your membership options at >>> http://mailman.mit.edu/mailman/listinfo/piclist >>> --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .