Lazer Tag Team Ops (LTTO) - Learning Grenade

(27 Jan 2006) There have been a few reports of problems with the current LTTO Grenade Firmware.   Most likely it is timing problems related to oscillator calibration, and slightly incorrect assumptions about the accuracy of the LTTO's internal clock accuracy.  It worked fine on my 12F629 and my LTTO guns, but it's possible that you could have problems.  There is a solution for this, but I won't get to it until some other projects (5.XX and 2.XX) are farther along.  Let me know if you have problems.  --Jim

Here is the prototype circuit for a "grenade" device that is compatible with the popular LTTO taggers.  It features ultra-low power consumption to ensure long battery life.  If you are interested in building this device, contact us via email.  This code will not posted for download.  This is a very simple design so no PCB design is presented.

OPERATING INSTRUCTIONS

Power On / Power Off - There is no on/off switch.  The grenade will automatically enter low-power mode to conserve the battery while it is not being used.

Locator Mode - After the Grenade has “fired”, it will enter into Locator Mode.  In this mode, the Grenade emits a beep and flashes the Status LED every few seconds.  This makes it easier to find the grenade.  Press and hold either button to stop the locator beacon and reset the grenade.

Using the LTTOG:

Modes -

Button 1 = Normal Grenade: 10-second fuse, 8 Tags (2x Full MegaTag)

Button 2 = Crazy Grenade: 5-second fuse, 10 Tags (random timing)

To Arm the Grenade - Press and hold ONE of the buttons.  After about 1.5 seconds, the Status LED will turn ON and you will hear a double-beep indicating that the grenade is “Armed”.  Continue holding the button until ready to toss.

Toss the Grenade - When you let go of the button, the countdown "fuse" will begin.  This is a series of beeps that gets faster until the grenade "fires".

Cook it Off - Release the button and hold onto the grenade for a couple seconds before tossing it.  Listen to the beeps getting faster, you'll know when to toss it!  This will help prevent your target from throwing it back or leave them less time to escape.

Learning Mode - To enter the grenade’s learning mode, press and hold BOTH buttons.  The Status LED will turn ON to indicate that the grenade is ready to receive.  Now just point your LTTO tagger at the grenade and fire.  The grenade will learn your player ID and team ID.

Power On Delay - Any time the battery is first connected, or after it fires, or after learning a new player ID there is a 30-second delay before it can be armed again.

Note that in the schematic there is only one IR LED and only one super-bright LED shown.  In most end designs you will need at least 4 to six of each.  This is an area for some experimentation and you may need to adjust some component values accordingly.  Pin 3 of the TSOP is tied to GPIO 1 so that power to the TSOP can be turned on and off.  This is to help conserve battery life.