Bread Board Power Supply
The AMS1117 5V linear regulator in that breadboard module has a dropout voltage of up to 1.3V at 800mA, and there is also a silicon diode in series with the power socket that drops another 0.7V. Therefore at best you will only get a little over 3V out of it.  

To get the full 5V from your USB power supply you need to plug it into the USB port on the breadboard module!