Hello!
I am developing a project to output an image from a file from the SD.
For the efficiency of the output, it is required to reduce the read buffer to the optimal (512 by 64 bytes).
The buffer reading time of 512 bytes is too long and it needs to be broken down for short periods of time.
How to reduce the read buffer to 64 bytes?
I use the standard SD library.
An example of reading data from a file by 48 bytes in microseconds ():
Initializing SD card...initialization done.
Writing to test.txt...done.
test.txt:
3568 // reading to the buffer + read from buffer 48 bytes (48)
444 // read from buffer 48 bytes (96)
444 // read from buffer 48 bytes (144)
436 // read from buffer 48 bytes (192)
436 // read from buffer 48 bytes (240)
440 // read from buffer 48 bytes (288)
436 // read from buffer 48 bytes (336)
444 // read from buffer 48 bytes (384)
436 // read from buffer 48 bytes (432)
436 // read from buffer 48 bytes (480)
3596 // reading to the buffer + read from buffer 48 bytes (528 > 512 bytes of the buffer)
448 // read from buffer 48 bytes
444 //...
440
436
444
436
444
436
440
444
3592
452
436
436
444
440
444
440
436
444
436
3568
448
436
440
436
Time in 440-480 microseconds is very good, but the time 3.5 milliseconds is very critical for my project, smoothness is important.