Hello, I'm very new with mbed. I am trying to write the 3 accelerations measured with a adxl335 accelerometer to a SD card using mbed nxp lpc1768 at the highest possible frequency. I also write on the SD card the instant of acquisition. The result shows a very variable frequency of acquisition: I am able to record at a rate of (10 measurements/1 ms = 10 KHz) but from time to time the frequency drops to (1 measurement/10 ms = 100 Hz). This frequency drop occurs like 8 times every second. After doing some research, I found that the reason could be that the mbed spends some time on opening memory blocks on the SD card (is that correct?) so that explains the drops. Since I need a constant frequency of acquisition, finally I cannot go faster that 100 Hz, but I need 500 Hz. Does anyone knows how to speed up the frequency of acquisition or how to regularize the period of acquisition? I am open to save data to other device rather than the SD card. After reading the following: http://mbed.org/forum/mbed/topic/719/?page=1#comment-3576 I know that Eli Hughes is able to log data at 1 KHz, however I am not able to understand or to use his code ChanFatFS. Thanks,