I am building a device on breadboard where there are 2 ICs: a microcontroller and some auxillary IC, they should communicate via SPI with a 4 MHz clock. Because I don't have enough place on my breadboard, I plan using two breadboards, microcontroller on one and other IC on other. The question is, can I transmit 4MHz 3V3 signal over a jumpre wire, just like on the photo:

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Will the signal be deteriorated? Where I can find some rule-of-thumb info about cables and their band-pass frequencies?

  • 4
    \$\begingroup\$ The capacitance of the breadboard is more likely to damage the signal, not the wires. 4MHz is slow (I often work with 20MHz SPI) - there's no problems using wires like those. \$\endgroup\$
    – Majenko
    Oct 1 '14 at 11:02

As Majenko pointed out, don't worry. there is no problems for 4Mhz 3v3. I myself working with 6Mhz SPI. it depends on your speed and the length of your wires.

longer wire = slower speed and vice versa

  • \$\begingroup\$ length/speed - ok, but does an insulation level of a cable matter? Those jumper wires don't look like heavy insulated ones. \$\endgroup\$
    – Mike Spark
    Oct 1 '14 at 13:28
  • \$\begingroup\$ @MikeSpark Not too much but it could be a bit important. generally, you can ignore it. I didn't have problem so far. \$\endgroup\$
    – Roh
    Oct 1 '14 at 14:19

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