I have an Arduino Micro and I want to connect an LCD and Bluetooth module to it. The problem I face is that there are not enough power pins for them both.

I understand that I probably need some external power supply for them, but I have no idea how to do this properly.

  • 3
    Just split the wire going from the vcc pin.
    – Gerben
    Aug 17, 2015 at 10:09

1 Answer 1


You can design/build/deploy a power supply that provides to each board (arduino included) the voltage it needs (but it's advisable to have modules working at the same voltage level) and that should be sufficient. As long as you have a shared Vcc-to-GND reference, it's enough.

To verify that the power supply you choose is ok, do the following:

  • check that the modules are compatible with its voltage (ex: all at 5V)
  • check that the combined power consumption of each module (you get that from the datasheet) is lower than the total power output of the power supply.

Additional checks:

  • check that the maximum voltage ripple provided by the power supply is lower than what the modules can tolerate
  • check that the peak current the power supply can provide is larger than the combined peak current of all the other devices.

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