Right again! The construction completely confused me as I missed the "i". The original code works, but I would certainly not have written it that way.Sorry for the...

Quite correct! So data never changes. Putting the statement data = data >> 1;after the else if clause will make it work.

kingca -All that has been said about the control of the HW is correct, but you should also have a look at your SW as well. The way your if - else if test is written...

When I google for "Arduino Mini USB Nano", the boards shown have a usb on one end and a 6 pin programming header on the other. If that's the case, I don't understand...

How are you reading the analog output? I don't see where that is done in your code. If it is the case that you are looking with your scope, but not seeing analog...

How are you verifying the timing of the clock pulses? Using a scope would be the best. You need to be sure that your timing is correct. Also check the voltage levels...

A key question is whether the sensors that are connected will transmit whenever they want (in which case you must handle multiple channels of asynchronous input)...

If your goal is to understand the architecture, I suggest "Computer Architecture - A Quantitative Approach" by Hennessey and Patterson. Explains the details in a...

Others have pointed at this, but let me make a clear statement and quote from the mbed documentation for the function: The input data is complex and contains 2*fftLen interleaved values as shown below. {real[0], imag[0], real[1], imag[1],..} The FFT result will be contained in the same array and the frequency domain values will have the same interleaving. If...

The suggestion of a scope is a good one! A logic analyzer could work also - a really cheap one should do it here since the frequencies you're dealing with are pretty...

OK, here are a couple of thoughts to find the problem. SPI is generally pretty simple, but there can be stumbling blocks.First, are you sure the part is getting...

Just looking at the flow chart you show (wait for ff, then read response) and considering that you get ff back from the part makes me think things may be working....