I now try to port into OpenWRT (trunk r29558 on the TP-Link MR3220 device) the console program for USB-thermometer BM707, the source for x86 linux placed here.
I have translated this program from C++ to C and have compiled that successfully, but it works partially - the reading themperature from previously defined sensor ID works, but scanning of connected sensors returns libusb error.
I have consulted with device author, and the answer was - not works 1ms delay inside the device control protocol.
I have tried the function usleep like this:

printf ("Start pause 10sec\n");
int n;
int result;
for(n=0;n<10;n++) { result=usleep(1000000);}
printf ("End of pause 10sec, result=%i\n",result);

but it also doesn't work.
What is the right way for creating 1ms delay between operators in OpenWRT?