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What is the maximum range of SPI communication protocol ?

MHass.2
Associate III

Hi,

I want to use accelerometer using stm32f4 mcu with SPI protocol.

The range is between 1 and 2 meters. Is this work good ?

Thanks...

3 REPLIES 3
Pavel A.
Evangelist III

SPI over 2 meters? No way, without extender

-- pa

Winfred LU
ST Employee

Technically you may do that but it will not be a trivial task.

The maximum possible length of SPI line at a specific clock frequency is limited by the phase delay between CLK and MISO seen by the master.

Line driver may be required. Typical issues of a long transmission need to be taken care: impedance matching, inductive noise, etc.

Ozone
Lead II

As mentioned, for high speed, you would need impedance-matched lines and transceivers.

However, most accelerometers have a relatively low bandwidth, I guess 1ksps or less would do for your purpose.

You can reduce the SPI clock frequency, to ease the line requirement.

About 100 ... 200kHz should suffice.