Using Eagle to create Electron board

Hi… I am in the process of creating a Eagle board to place the Electron on. The board itself will mainly use the Digital pins for high/low determination on a pin(s). My question is do I need pull ups resistors for each pin or are they built into the Electron?

If I need pull ups can I get away using just (1) pull up resistor for more than (1) pin?

Thanks

Yes, there are internal weak (~40k) pull resistors (INPUT_PULLUP & INPUT_PULLDOWN) and no, you can’t use one for multiple pins since you’d introduce “cross-talk” between input signals via the common side of the resistor.

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OK Thanks… does that say that somewhere in the the Doc? Maybe I missed it!

It does :wink:
https://docs.particle.io/reference/firmware/photon/#pinmode-

Thanks…