I'm writing on a SD card the value of a measured voltage. I've a good sampling/writing frequency but regularly the acquisition take a lot of time (like 4000us instead of 400us). I noticed that this "pause" appears every 85 values (my values are 6 bytes long, so it appears every 510 bytes).
So I have hypothesized that there is a buffer of 512 bytes somewhere which is full and need some times to empty.
But I don't know where is this buffer. In SDcard? in Arduino? And how can I avoid this issue?
And here my loop to read the value and write it on sd card:
Hope you can help me guys !