Step 1: In any USB cable(for example, the one you use for charging your phone), there are 4 wires.
Step 2: Use your multimeter to find out which two wires give +5V. One wire should be +5V and the other should be -VE (GND).
Step 3: Connect the +5V wire to +ve point of screw terminal and -ve to – (minus) point of screw terminal.
The object counter can now be used. Likewise, you can power up the infrared transmitter also.