A way to measure the voltage in a battery

Step 1: Materials

Materials needed in order to create the Arduino Battery Tester:

Arduino Uno
2 yellow LEDs
1 Red LED
1 RGB LED
4 330 ohm resistors
9 wires (colors don't matter)
Any 1.5V battery

Step 2: The Steps to Make It

When connecting the normal LEDs (not the RGB) connect the longer metal leg to the positive side (the wire that comes out of the numbered pins). The smaller side should be connected to a resistor and a ground pin. When connecting the RGB LED the longest leg is negative. The pin in the center is the green LED control. Connect the green control to the ~10 pin and make sure that a resistor is between the wire coming out of the pin and the leg of the LED.