Saving Data

Archive
1

Hi all,
How can I store some data on flash? And how can I read?
Thanks.

2

Use EWR (Extended weak references).

There is an example that comes with .NET MF.

On my machine it is located at C:\Users\mike\Documents\Microsoft .NET Micro Framework 4.2\Samples\ExtendedWeakReferences

This assumes that you want to be able to write it from your program and then read it back.

Otherwise, consider using resources. http://wiki.tinyclr.com/index.php?title=Loading_Resources for read only.

3

Thanks a lot. I’m checking.

4

Note that EWR is not available on Cerb family http://wiki.tinyclr.com/index.php?title=FEZ_Cerberus_Developer#Why_EWR_is_not_available_on_cerb-family.3F

5

Sorry for late reply.
I tried EWR sample. It works for reboot, but not for power down. Do I miss something? I want to save some data permanently.
Thanks a lot.

6

there is a parameter that determines whether the object survives power down.

check out this discussion http://www.microframework.nl/2008/12/23/extended-weak-references/

7

Thanks a lot Mike. Sample works fine.
But when I combine it with my application, I have trouble. I think my problem is shutting device down. My code doesn’t reach the end of Main because I unplug.
Application.Current.Shutdown() gives an error. Any suggestions?

8

No sure what you mean? With Gadgeteer, main should never exit. Gadgeteer is event driven.

Also, an embedded application should never “shutdown”. What are you trying to achieve?

There is a delay before your EWR object is actually written to flash. I have not used it, but I believe there was a flush function added to the EWR functionality in MF 4.2 to write any pending EWR objects to flash.

9

I copied the code from sample to my application. It works if I reboot from Debug, but it fails if I unplug or reset. As I see, only difference between Sample and mine app is Sample finishes Main, but mine doesn’t. Thats why I asked. I will keep trying. Thanks.

10

hi a quick search in code share gave many examples:
here is one:

http://www.tinyclr.com/codeshare/entry/196

please do a search and study those examples.

Good luck.

11

and here is a post that talks about the flush function that mikes mentioned:
http://www.tinyclr.com/forum/topic?id=3833

12

Thanks a lot.

Of course I did. I think I didn’t choose correct keywords :S
Thanks again.

13

Yah i know; the search on CodeShare is a bit funky and has it’s own mind…so you might want to start using bing to search Codeshare:

type this in the bing search:


flash site:www.tinyclr.com/codeshare

and here is what i got when using the search:
http://www.bing.com/search?q=flash+site%3Ahttp%3A%2F%2Fwww.tinyclr.com%2Fcodeshare&go=&qs=ds&form=QBLH&filt=all

Cheers.