Airsoft/Paintball Scenario Bomb (Timer)


I need to create a scenario (inert) bomb for airsoft. This is basically a timer with a siren that can be armed and disarmed, making a Search and Destroy/Sabotage gametype possible.

Basically I need to make something like this:

I'm thinking the Arduino Nano board would be the best one for this?

I was wondering if anyone knew what exactly I'd need. I need to do it on a budget, from what I can tell I need atleast this much:

  1. Piezo Siren

  2. 2x16 LCD display

  3. Two Push Buttons (Green and Red) for arming and disarming From Radio Shack.

  4. Printed Circuit board (This is basically a breadboard, correct?)

I am unsure of what I need

Additonally I'd like to add in a key system. Basically a switch that is off without the key inserted (connecting the circuit). This would allow me to tether the key to a tree or other object and force them to be at the location before they can arm it.

If someone knows how I could incorporate an Accelerometer so that once the bomb is "armed" it can't be picked up (but won't go off if slightly bumped) that would be preferred.

Overall this circuit needs to have: 1. a push button with an arming timer. 2. a push button with a disarming timer 3. LCD screen to display the progress bar/time remaining 4. A method for ensuring the bomb is not armed early. 5. A loud siren for detonation.

I know I may sound "noobish" posting this, and may of left out some important aspects.. I promise I pick up on things fast, I just need a jumping off point.

Thanks for any help; it's greatly appreciated. Serial Addressable screen, I know its expensive, but it makes it much easier to integrate with the Arduino. The advantage of this one is that it will only require two I/O lines to control. Two Pushbuttons: These are momentary for the arming process. For the key I would do something like what the example there did and use a plug with some soldered pin bridges inside it to prove insertion, and just act like this is another switch. As far as timing goes, you could use the internal millis() clock in the arduino or I think you can get a realtime clock unit for it too. As far as other bits go, you will possibly get away without using a breadboard as you can wire the switches and screen to the sockets on the arduino fairly simply. You will almost definitely need some way of driving the siren, as the I/O pins on the ardino will not be able to support a siren, so you will need some circuit with a transistor or relay of some sort that triggers the siren. unit actuually has two channels so you could possibly put a string of LEDs on the second channel for visual activation. Also, depending on the siren you buy, it will likely need a different voltage than the arduino, generally it will need 12v as these units are designed for automotive applications. So then, if you start with a 12 Sealed lead acid battery as your power source, you will need a regulator to power the arduino off. This might do you nicely.

Thank you very much! I'm not quite sure if I'm ready for arduino yet... I might just work something up with 555 timers for this specific project. This is great and very detailed though. Definitely saving a copy for reference.

If you can do 555 timer based stuff, arduino is gonna be easy.