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10 years, 2 months ago.
Reading from SD Card
Hi, i want to read and write from a SD Card and tried it like in the mbed book i have.
Not i want to have a good perfomance. On the SD Card are collums with 2 float variables. I need to know 1 collum each 1ms. So i dont want to read the whole file only one coloum per step. Is there any possiblity?
So Step 1 first collum Step 2 second collum etc.
1 Answer
10 years, 2 months ago.
SD cards can only be read per 512 bytes, so reading per column is not possible. In general reading a whole block and then reading from that waht you need will be faster. This can be used to decrease the time your mbed is waiting for new SD card data: https://mbed.org/users/Sissors/code/SDFileSystem_RTOS_HelloWorld/. However you will then have to figure out how to synchronize different threads, and less than 1ms delay will be a problem.