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10 years, 1 month ago.
SDFileSysten vs SDHCFileSystem
I am working in some audio file streaming from a SD Card.
The Simple Wafe Recorder Player example uses the SDHCFileSystem (http://mbed.org/users/shintamainjp/code/SDHCFileSystem), which works fine, however, the mbed library is outdated.
When I update mbed, it wont compile anymore. But if I use SDFileSysten, together with the latest mbed library, (http://mbed.org/users/mbed_official/code/SDFileSystem), the simple Wafe Recorder example displays only half of the SD upload/download speed and also the sound is very poor (recording and playing).
???
1 Answer
10 years, 1 month ago.
From the first link, the subtitle of the library:
Quote:
Local copy of the SDHCFileSystem. But changed the I/O frequency to 20MHz.
So 20 times the regular speed, that explains the difference.
Now I thought the regular one was changed to allow modification of the transfer speed, but I don't see it currently, so prolly someone should check what happened there. But on line 210 you can change the transfer rate.