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arunb
Joined: 08 Sep 2003 Posts: 492 Location: India
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Is MMC better than Compact Flash Type II ??? |
Posted: Fri Nov 11, 2005 4:01 am |
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Hi,
I would like to store large amounts of data( to be used in a datalogger) ,several MBs. I found that compact flash could be used , but the number of pins in the card is quite a lot.
But an MMC card has lesser number of pins. So do you think using a MMC card is better than compact flash , also please advise on what type of MMC (if there is such a thing) card I should use. Also is there any connectors available for this ??
thanks
arunb |
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Bart
Joined: 12 Jul 2005 Posts: 49
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Posted: Fri Nov 11, 2005 3:31 pm |
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Hello Arunb,
You are not the first who wants to store a lot of data (so do I)
MMC seems to me the most simple in connection and in code.
Search the forum for MMC and you will find a lot of examples (even code)
Connector are available and if you can't directly find one, you can test with an old floppy drive connector.
(See also a topic from me : http://www.ccsinfo.com/forum/viewtopic.php?t=24909 )
It becomes harder when you need those logged/saved Mb's on a PC ... _________________ I like Skype (www.skype.com), my username is BplotM |
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arunb
Joined: 08 Sep 2003 Posts: 492 Location: India
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RE: |
Posted: Sun Nov 13, 2005 1:53 am |
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Hello Bart,
Thank you for the reply.
Is there only one kind of MMC, which has 7 pins ??
Also is a floppy disk connector required for connecting the card ??
Please also advise where I can get the specs for the card ??
thanks
arunb |
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ckielstra
Joined: 18 Mar 2004 Posts: 3680 Location: The Netherlands
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Re: RE: |
Posted: Sun Nov 13, 2005 10:25 am |
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arunb wrote: | Please also advise where I can get the specs for the card ??
| The official place to look for documentation is www.mmca.org. Problem is that depending on the version number they are now charging $500 or $1000 for this documentation while two years ago the documentation was available for free.
Searching the internet you can still find some of the older specifications floating around, for example v1.7: http://www.sandisk.com/download/Product%20Manuals/Product%20ManualSDCardv1.7.pdf
These older versions are still valid as all the newer cards are backwards compatible. |
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arunb
Joined: 08 Sep 2003 Posts: 492 Location: India
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RE |
Posted: Tue Nov 15, 2005 5:53 am |
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Hi,
I have bought a 128 MB card, it contains 8 pins only. I found a similar card (256 MB) but this had around 12 pins, 8 pins were arranged in one row and 4 on a second row, apart from this it was similar in size to the 128 MB one, the dealer told me it was compatible with Nokia phones.
The specs posted by ckielstra showed only 8 pins, do you think the second card (256 MB) is compatible with the first one. ?? also how do I determine what pins are not required ??
Kindly advise what I should do
Thanks
arunb |
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ckielstra
Joined: 18 Mar 2004 Posts: 3680 Location: The Netherlands
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Re: RE |
Posted: Tue Nov 15, 2005 7:22 am |
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arunb wrote: | Hi,
I have bought a 128 MB card, it contains 8 pins only. I found a similar card (256 MB) but this had around 12 pins, 8 pins were arranged in one row and 4 on a second row, apart from this it was similar in size to the 128 MB one, the dealer told me it was compatible with Nokia phones. | Most likely you have an MMCplus or MMCmobile memory card, these are newer versions of the MMC cards which have more pins for a higher data throughput. When using the MMC in SPI bus mode you are not using these pins.
I have no more info on these cards, but as they are backwards compatible I assume you don't have to connect anything to these pins in SPI-bus mode.
For a short description on the pin layout see http://www.transcendusa.com/Support/DLCenter/Datasheet/TS2GMMC4.pdf |
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