Step 5: Put it all togother
Now take the LED and solder ti. (picture 3)
Take the resistor and connect the negative(shorter) pin of the fototransistor and the positive(longer) pin of the LED whit the 330 Ohm resistor,(picture 4) and cut the pins.(picture 5)
Solder the switch in between, a little bit down.
Now take the 9V battery clip and cut it about the lenght so that you can connect it to the switch and the fototransistor. Save the black wire from the battery clip because you are going to need it.(picture 6)
Connect the black wire from the clip to the switch, and the black wire that you saved, from the switch to the negative(shorter) side of the LED.(picture 7)
Connect the red wire to the remaining pin,the positive(longer) side of the fototransistor.(picture 8)