SD Card Size Recommendation

General discussion about topics related to OpenMV.
robmurrer
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Joined: Sat Feb 13, 2016 1:13 pm

SD Card Size Recommendation

Postby robmurrer » Sun Feb 14, 2016 12:44 pm

What SD card size should I get for the OpenMV2?
Should it be formatted as FAT?

I'm a little confused on how to write to it also. Could someone point me to some sample code?
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iabdalkader
Posts: 542
Joined: Sun May 24, 2015 3:53 pm

Re: SD Card Size Recommendation

Postby iabdalkader » Sun Feb 14, 2016 1:24 pm

I'm using a 2GBs uSD, and tested 8GBs (higher capacity should work)

You just write to the root dir and the camera will write to whatever storage is used.

Code: Select all

fp = open("/helloworld.txt", "w")
fp.write("HelloWorld!")
fp.close()
Or:

Code: Select all

with open("/helloworld.txt", "w") as fp:
    fp.write("HelloWorld")
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petri
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Location: Finland

Re: SD Card Size Recommendation

Postby petri » Sun Aug 21, 2016 12:29 pm

iabdalkader wrote:I'm using a 2GBs uSD, and tested 8GBs (higher capacity should work)
On OSX, I have tried two different 8GB uSD cards that are formatted as FAT32 and neither work with the camera. Both result in two green blinks and one bright white blink upon booting (via USB). After that, the cards show up normally as removable media, but the camera does not work. It's as if it's not connected at all. The IDE does not recognize the camera.

I also saw that the internal storage is formatted as FAT12. Would formatting the SD card as FAT12 help?
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kwagyeman
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Re: SD Card Size Recommendation

Postby kwagyeman » Sun Aug 21, 2016 12:46 pm

The camera should support FAT32. Try deleting the volume and re-creating another FAT32 volume but limit the size to 2GB. The Micro Controller supports SDHC and we're using a library that supports SDHC but I think there might be some weird issue that needs to be debugged to get higher than 2GB working.
Nyamekye,
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petri
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Joined: Tue Jul 05, 2016 11:52 am
Location: Finland

Re: SD Card Size Recommendation

Postby petri » Sun Aug 21, 2016 1:16 pm

kwagyeman wrote:The camera should support FAT32. Try deleting the volume and re-creating another FAT32 volume but limit the size to 2GB.
I reformatted the card first as ExtFAT (out of curiosity, did not work) and then as FAT32. A funny thing happened; the card now shows as a regular ~8GB capacity on the OSX Mac, and it works now on the camera too, but only shows more or less half the capacity, ie. < 4GB formatted available space (when mounted via the camera).
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kwagyeman
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Re: SD Card Size Recommendation

Postby kwagyeman » Sun Aug 21, 2016 1:17 pm

Yeah, that's happened to me too. Pretty sure that's a bug. Weirdly, I believe the issue is buried in the MP code. Ibrahim will have to fix this.
Nyamekye,

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