Concurrent file operations using FSRW?

Hugh

Hi,

Ideally I would like to write to two files on an SD card concurrently. I'm a bit tight for cogs so can't afford to have two instances of FSRW, so I wondered whether it would be realistic to alternate between two files, closing and opening each in turn? If feasible, if this going to be too dependent upon the SD cards used?

Any thoughts appreciated,
Hugh

Rayman

I believe FSRW will let you read from 2 different files or read from 1 and write to another.
I think you can write to 2 files to, but maybe you have to make a minor change to the driver...
If you look at the top of the fsrw file, there are some notes about this.
I think you have to change some variables from being in a "DAT" section to being in a "VAR" section (or vice versa)...

Dave Hein

FSRW allows for multiple open files at the same time by accessing them as separate objects. Just use something like this

obj
  fsrw[2] : "fsrw"

This will allow you to read or write 2 files at the same time. If you need more simultaneous opened file just increase the object array size.

Mike Green

You cannot write to 2 files simultaneously from two different cogs. FSRW is not written to allow this.

Dave Hein

Actually, you can use FSRW from different cogs, but you need to use a lock so they don't step on each other.

Hugh

Thanks. I'll give it a go. Hugh