SD read/write variables

hy. I tried the read write example… but it takes too long.
I want to store 3 variables very often so it has to be fast as possible.
int x <= 300
int y <= 10000
float z = 0x0003 for example
any ideas to speed it up a little bit?

any ideas to speed it up a little bit?

Use an external SRAM chip fitted to the SPI bus to store the samples into. When you have finished the run of data then dump the contents of this SRAM chip into the SD card. To speed up the operation you might like to bit bang the SPI on the SRAM chip so you don't have to keep opening and closing the SD card's files.

I have no space left to put more componens in my construction. every qubic millimeter is used compleetly... so the external SRAM doesnt fit

So you are stuffed I think.

What are you actually trying to do ?

The problem may be, the fairly long and variable latency of the SD card devices. There is no easy way of getting around this.

One way is to use SPI ram, as suggested.

Another way is to use one arduino to do the sampling and another arduino to deal with the sd card.

s to use one arduino to do the sampling and another arduino to deal with the sd card.

If there is no room for an 8 pin IC then there is no room for another Arduino.

The OP has painted himself into a corner.