SPI read and write through wires?

Discussion in 'General Electronics Chat' started by picstudent, Apr 17, 2009.

  1. picstudent

    Thread Starter Well-Known Member

    Feb 3, 2009
    Can I read a SPI ADC chip located in another PCB connected through say a 15Cms wire. CLK, SDI,CS and SDO will be wired using cables from PCB to PCB. Is it Ok to do so?

    What are the constraints or limitations in such an approach if any?

  2. gotumal

    Active Member

    Mar 24, 2008
    Affecting factors could be the speed at which you are operating your SPI, voltage (+5,+3.3V), type of cables (RC) etc.
    As a rule of thumb, SPI, I²C are not meant for interboard communication. But of course it depends on impedance of cables running around.
    Once I used SPI with cables, I checked the quality of signal with scope for the max speed; perticulary the edges.