When using a USB Memeory stick and the MKK v4 USB Host and Flash FS, is there anyway of determining when it is safe to remove (unplug) the memory stick?
Yes, it is after you close all open files (with fclose).
Thanks Milorad, but the LED on various USB memory sticks I have tried continues to flash after the fclose command? Does this mean that the memory stick is still writing the file?
LED on the stick usually shows that USB host is active, so sending start of frame signals, it does not mean it is writing or reading from the stick. The LED could only be turned off by driving VBUS line low, you can use usbh_uninit for that, but after that Host will not detect new connection untill usbh_init is called again.