Modules sharing the same power source

I have an Android Pro Mini 5V and I am reading from an analog device (SparkFun Electret Microphone Breakout - BOB-12758) from pin A1. It works as expected and I see data on the serial port.

Now, to send that data to my android phone, when I connect a bluetooth module (JY-MCU) - I notice that as soon as I connect the VCC of the bluetooth module to the VCC on my breadboard ( where the microphone is also connected to the board), the data coming from the microphone goes corrupt (I start seeing lots of 0s and 1023s).

When I connect my bluetooth device to a separate power source, it works just fine.

Any clue what might be going on? Bad breadboard? Not powering all my devices with enough Volts/Amps? I am using USB from my laptop to power my electronics for this prototype.

USB is 500mA. Do your calculation.