Propeller newbie using eeproms

scochar

Hi I am working on an application that currently uses microsd cards to play .wav files - would like to eliminate using micro sd cards and use large eproms instead. Total data could be formatted to be less than 8 megabyte total (making 2GB+ SD cards overkill).

Is there a filesystem in place already for eeproms that can be used?

Thanks, scott

Mike Green

There's a driver for Winbond serial flash memories that come in sizes up to 8 MBytes. The driver provides for creating / opening / reading / writing named files. There's no update in place and the wear-levelling is primitive, but the driver is quite useful. There's even a loader to load and execute Spin binaries.

Using ordinary EEPROMs, you can attach up to 512K per pair of I/O pins and use any of several drivers. There was a very simple file system that was part of the Propeller OS mentioned in Graham Stabler's Good Thread Index here. This provided for files up to 32K in size with 8.3 file names. It could handle several pairs of I/O pins for I2C busses.

Cluso99

Welcome to the Prop Forum. This forum is very active and you can ask lots of questions here. Don't be intimidated by what you may ask - we were all there once although we quite often forget that. If anyone refers you to a manual or thread, please don't be offended - it is just often better explained there. If you then don't understand ask again with more specifics.

There are Flash SPI chips available which do 8MB. IIRC the W25X64 is one such chip and is available from either DigiKey or Future Electronics (not Futurelec).

I am unsure if a FAT16 driver for SPI chips has been done. However, it should not be too difficult to match the FAT16 driver to a SPI device instead of the SD device as they are usually handled by different objects. You can check out Kye's driver "SD 2.0 ..." http://forums.parallax.com/showthread.php?t=122991
and ask there if it does not support it. IIRC Kye was thinking about supporting SPI chips. Another possibility is to check the OBEX (object exchange) for a driver. Maybe Mike Green may chime in as he has done work in this area too.

scochar

Thanks for the welcome - I'm never insulted by links to other threads - I know a lot of what I need to learn has been covered 100s of times before, sometimes you just have to find it.

I've decided to stick with SD cards for now, since one of the threads talks about being able to use 2.0 to open 2 files at once for read, which is what I really need to do - at a hobbyist level I don't mind having 2 sd card slots, etc. but this design is for other people to build, too, and I'm trying to keep the overall cost/complexity down.

Now, I'm having a problem where [I think] the SD read engine is crashing (have not upgraded to 2.0 yet) - anytime multiple requests in a short time occur. I'm going to add some debug code so I can see what's going on (I've got 8 LEDs to show me some status)

thanks, scott