I use an Arduino Uno and I have a 3cell 12v lithium ion battery as my power supply.
When I connect the battery to the Arduino board and supply my sensors(by sensors I mean anything e.g an IR sensors or even a bluetooth module) with the Arduino board, everything is fine and I have a clean analog read through my analog pins. but the problem starts when I supply my sensors with the battery through a 5v regulator. when I do this, my sensors or modules turn on but the analog pins only take noises or my bluetooth module stops showing me the words that I send through my phone.
Please I need help.