something wrong with SPI commucation of two stm32

Hello everyone.Recently I have had two stm32 chips to communicate by SPI,then I had a difficult problem.My goal was letting the master and the slave exchanging one byte data,just one byte.after I wrote...
Descriptor for a switch or something similar

Hello! I have a problem. I have a Freescale Flexis with JM128 32-bit microcontroller. Now I want that the host i regognized by the Pc as a device. So the Pc have to indicate that the host have LED on...
Something wrong

double calc( int angel) { return sin(2*pi*(5/48000)*l); } Why do the function always returns zero?
adc using STM32

I get only 4 values in adc polling. Could anyone suggest where am i going wrong
How to time something in uVision2?

I'd like to measure how many instructions occur between successive visits to the same breakpoint. What is the easiest way to do this in uV2?