REAL cell phone remote relay \ remote firework starter

Step 5 Cellphone part

Now this is the cellphone part, I wired the cable in where the speaker for the ringer would be. I used a multimeter to test the voltage out on calls to know which pin was + and -. Once this is done, you have to REMOVE the speaker or it shorts the circuit and device will always be on.

NOTE: if you test it and when the phone rings the test LED does not light and you measure the output voltage as a fiew milli-volts, you have to invert the cables you put in the cellphone.