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joseph20480
Joined: 21 Dec 2011
Posts: 42
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| ex_mmcsd : Init ok with or without card... |
 Posted: Thu Dec 22, 2011 3:01 pm |
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Hi !
I try to connect a sdcard/mmc to a pic (pic18f4550 / CCS 4.114). For that I want use the ex.mmcsd... but I have somethings not expected.
When I call the function mmcsd_init(), she return alway ok... with or without memory card.
It's a another of ccs or I have forgotten something ?
Thanks in advance.
joseph |
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temtronic
Joined: 01 Jul 2010
Posts: 9178
Location: Greensville,Ontario
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| Posted: Thu Dec 22, 2011 3:26 pm |
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Please provide us a schematic diagram of your system.
As well as your 'main' program. |
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asmallri
Joined: 12 Aug 2004
Posts: 1634
Location: Perth, Australia
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| Re: ex_mmcsd : Init ok with or without card... |
| Posted: Thu Dec 22, 2011 5:24 pm |
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| joseph20480 wrote: | Hi !
I try to connect a sdcard/mmc to a pic (pic18f4550 / CCS 4.114). For that I want use the ex.mmcsd... but I have somethings not expected.
When I call the function mmcsd_init(), she return alway ok... with or without memory card.
It's a another of ccs or I have forgotten something ?
Thanks in advance.
joseph |
I cannot speak specifically to the CCS implementation however it maybe that any response other than 0xff from the card is considered to be successful. If you do not have a pull-up resistor on DO of the SD/MMC card socket then without a card the input to the PIC is floating as a consequence the PIC may, and often will, read a non 0xff value.
_________________
Regards, Andrew
http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!! |
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joseph20480
Joined: 21 Dec 2011
Posts: 42
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| Posted: Fri Dec 23, 2011 2:38 am |
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Thanks for your reply,
I will seen my schematic and post more informations....
About your reflexion, that is the sd card not responding seem to be Ok....i'm not sure... |
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