Hey guys I am currently working on a project were I have a recoil laser tag pistol that I have gutted to make a sci-fi riffle, I have added an Arduino nano to control some LEDs and a sound module I picked up. Now my question, I want to be able to have the LEDs flash and the sounds happen when different buttons are pushed on the recoil circuit. Such as when the power button or trigger is pressed. Both circuits are running 5V and it seems that just running another wire from the button to the Arduino does not seem to work.
What would be the best thing to do to connect these two circuits and be able to pull inputs to the Arduino? Should I look at getting a relay? Has anyone done anything similar?
Sorry if this is not the right place for this question I am new to the world of Arduino.
Thanks for your help.
You have LEDs, sound and button.
Attach the schematics.
This is the closest to what I have done, currently I have tested all the Leds and had them involved in my program to ensure they are functioning and the wires are hooked up. I have not had a chance to test the sound as the SD cards I ordered the wrong size was sent and do not work with the MP3 module I have.
All the buttons are part of a separate circuit and as that was purchased I am not sure of it's schematics. My hope is to get the Arduino to receive inputs from the buttons and flash the LEDs and play WAV sounds. I have both circuits with a common ground and still working on the coding.
Hi,
Welcome to the forum.
Please read the post at the start of any forum , entitled "How to use this Forum".
OR
http://forum.arduino.cc/index.php/topic,148850.0.html.
Then look down to item #7 about how to post your code.
It will be formatted in a scrolling window that makes it easier to read.
Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
OPs, Fritzy;
When you connect to the laser gun circuitry, do you include connecting the gnd of the controller with the gnd of the gun?
What model Arduino are you using?
Thanks.. Tom.. 
Fritzing pictures are NOT a schematic. Any schematic, even something drawn by hand on the back of an envelope is better than a Fritzing picture.
Thank you for that advice, I did not draw out the circuit and just did a quick google search. To be honest I don't understand what the circuit I am working with has to really do with my question. I was wondering what people generally do when trying to get input to the Arduino from another circuit.
The simple answer is connect the signal and (this bit is important) also connect the grounds (GND or battery -) of the two circuits together. You always need a common reference for a signal and that is almost always GND.
Steve
