Question

You are building a microcontroller-based system to measure impacts to the human body. The design measures the analog output of an accelerometer using a 16-bit ADC that samples at 42,000 Hz. Assuming the microcontroller communicates with the ADC using SPI, what is the theoretical minimum SPI frequency necessary to transfer this data volume?

Answer 1

Dear Student,

Sampling frequency is the minimum frequency required for sampling and is 2 times the main frequency according to sampling theorem.

That is F sampling = 2 * F main.

Here F main is the communication frequency at which data is coming to ADC through SPI.

From above relation it is clear that Fmain should be

Fsampling / 2.

Thatis Fmain = 42,000 / 2 = 21,000 Hz.

Therefore the minimum Frequency required for SPI - ADC communication will be 21,000 Hz.

Thank You. Have a Nice Day.