Power sources

Thread Starter


Joined Dec 9, 2011
Hi everybody,
I want to create a circuit which involve arduino Pro Micro, BLE breakout board and GSM breakout board.
I would like to know how to give power to these three.
For Arduino ProMicro, there is no big deal. I know how to do it? That require 5V
For BLE breakout board, that also require 5 V.
For GSM breakout board, that also require 5V.
For accelerometer, it require 3.3 V.

Do I need to give 4 different power(four different DC adapter) source by connecting ground together?
Can I used only two, 5V for ProMicro, BLE and GSM and 3.3V for accelerometer. If I can, how to connect these three to power line (in serial or parallel).
Kind Regards,


Joined Nov 23, 2012
Use one supply for all of your 5V devices (parallel connection). All share the same ground and all share the same 5V. This assumes that your 5V supply can supply all the current they need (three devices added up). The fourth needs either it's own 3.3 supply or a low-dropout regulator feed from the 5V source used by the other devices. Make sure to connect the ground (0V) to the rest of the devices.