=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= HOME BUILT LASERTAG Design Description and Implementation Hints, Suggestions, and the Word of gOD =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Conceptualized, designed, built, tested, exploded, burned, mutilated, pierced, beaten, and otherwise thoroughly hell-bented by Mike Burke and Jeff Wovkulich. All rights and most lefts reserved. Void where prohibited by law or common sense. Post no bills. No animals or siblings were (seriously) hurt in this project. This project complies with FCC Rule 1298e12 Paragraph 17 Line 49 Word 6727 Nitpick 12. We checked, double-checked, and triple-checked these plans. We even passed them through the Check-A-Tron. But there is no way we can be ABSOTIVELY POSILUTELY sure that the plans are correct. Use your good judgment; if you see an LED in series with a speaker, or some other sort of nonsense, then please THINK TWICE before doing it. FROM THE WEB PAGE: Q: I hurt myself playing/using/building/looking at Home Built LaserTag ... A: Look, the U.S. is just too sue-happy. So, if you hurt yourself, get a doctor, get better, go play more HBLT. But don't come looking to us for money, cause not only do we not have any [RPI will keep us in debt way into the year 2050], but we didn't hurt you. I'm sorry if this sounds horrible, but its the truth. Just cause we designed the plans doesn't mean you should go out and beat each other with them about your respective heads and necks. For the record: We at HBLT, Inc. do not recommend even down-loading our designs. Who knows, you could get a paper cut on your wrist and die from an infection while printing them out! While your at it, you may as well never do ANYTHING ever again; you could hurt yourself. Furthermore, we support the first amendment greatly. This document, plans, and the accompanying web page are NOT meant to offend anyone. However, if you find .GIFs and text files about electronics offensive, you need to do the following: 1) Get some help 2) Get some help. I realize that these two points are technically one point, but I felt them to be of such enormous value to the offending person that they should be stated twice. Thank you for your support. <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< READ THIS >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> THIS PROJECT IS *CARDWARE*. If you find them interesting, useful, or otherwise not a waste of your time, we ask that you send Jeff and I a postcard. This could be a card from your home town, picturing a scenic view of St. Smithy's Leap or Rabbit Bridge or New Jersey Toxic Pits or whatever. Just send us one. Eventually, we will post a picture of the Wall O' Cards. Its all we ask for our hard work (actually, we calculated that if we made $2 on each set of plans we gave out, and we gave out five hundred plans, that we would have made $2.20 an hour. I'd rather work at McD's...). In all seriousness, these plans are the result of a year and a half of very hard work, and Jeff and I reserve all the rights to them. Distribute them as you will, for free only. Don't go making a profit off our backs. If we wanted to sell them (and get gyped) we would (see paragraph one above). But, if you get a strange urge to send us money, cool! <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< READ THIS >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> So you have the HBLT plans in your hot little hands. Well, this little text file is the Essential Guide to HBLT. You need it more than you need food. HBLT EMITTER (GUN): =-=-=-=-=-=-=-=-=-= Looking at the plans [hblt_gun.(ps|gif)], there are four major sections. The first is the left hand side that has two 555 timers, one over the other. This section controls the triggering of the emitter; it allows for one-shot, three-shot, or full-auto (depending on the switch configurations). SW3 selects between one and three shot mode, and SW1 selects full-auto fire when closed. SW2 when closed is the trigger itself. The second section is the 556 in the upper-middle potion of the schematic. This provides the 40KHz and 1800 Hz square wave outputs we use to trigger the sensor (Note: WoW (Worlds of Wonder, makers of the ORIGINAL Lasertag) used a 57.6KHz carrier wave. Their guns are NOT compatible with our sensor; however, we have gotten favorable results using the HBLT gun design and their sensor. We recommend using only our guns and sensors; however, in a pinch, one can use their sensors with HBLT guns.) The four (4) pots in the diagram control the output; we use the results in the table below, but we recommend that you tune the gun to your sensor by adjusting the pots slightly. TABLE: GUN VARIABLE RESISTOR VALUES Pot A1 5k Pot Tuned to: 1.1k Pot A2 100k Pot Tuned to: 63.1k Pot B1 5k Pot Tuned to: 456 ohms Pot B2 5k Pot Tuned to: 1.8k Pot C1 (on the trigger section) 100k Pot Tuned to: 75k The fifth, er third section is the 555 directly below the 556. This is used to output a tone to a speaker. The two pots can be adjusted to whatever values most please your ears (or whatever you use to hear with). The last section is the three logic gates and transistor output to the far right of the schematic. Use a Motorola 14011 or similar; any quad NAND gate will do though. The transistor picture is a Darlington NPN (the picture doesn't really show that). I used a TIP120. Also, just about any voltage over 5v can be used to drive the circuit; however, the resistor on the output Infrared LED will have to be changed. I recommend starting with a 20 ohm resistor and working down to as low as you can go until the LED overheats after a small duration (say, five minutes) of use. A note on lenses: we definitely recommend using lenses with the IR LED. Basically, put the lens at one end of a PVC pipe or similar material, and move the LED back and forth until you find the focal point. Its probably a good idea to use a visible LED for this. Dave Bodger's homepage (http://www.compulink.co.uk/~lasertag/lasertag.htm) has a very nice document on how to do this. HBLT DETECTOR (SENSOR): =-=-=-=-=-=-=-=-=-=-=-= The sensor consists of two parts: a small "sensor" unit, of which there can be up to five, and a larger "base" unit, of which only one is needed per player. The smaller unit (on the left side of the page) attaches to the larger unit by means of a cable to the 555. The display shown is not necessarily how to hook up the 14558 to the display; the chip's data sheets should be used to best determine this (each variety of driver chip has slightly different connections, also varying if you use a common anode or cathode display.) The sensor unit gets its input from the IR Module - this is the standard "silver box" module sold by Radio Shaft. The 567 is one of the few chips you cannot get at Rat Shack; it is a tone decoder. Essentially, it looks for the 1800 Hz signal. The base module uses a monostable 555 to trigger a .5 to 1 second delay on every"hit" detected by the 567. This pulse also increments a counter and buzzes a buzzer. When the hit total reaches 6, the counter latches and the buzzer stays on. It is a good idea to shield the sensor from sunlight by making a physical "lip" over the sensor, like the brim of a hat. MISCELLANEOUS =-=-=-=-=-=-= Most parts can be bought at Rat Shack, except for the 567 tone decoder and possibly a very high power IR LED. Go with Mouser or Digi-key for those. We have gotten 200 to 240 foot ranges from our guns on hazy days. Very bright sunlight almost kills the power of these guns (but then again, who wants to play in the sunlight?). Incandescent bulbs will also cut the range, but if only of the stadium variety. Fluorescent bulbs seem to not have much of an effect. We use two sensors on a headband; one front and one back. That seems to work quite well. A sensor unit (two sensors and a base unit) and a gun cost us about $35 to make; you should get comparable results as long as you mail order most of your parts. Getting them from Radio "You've got questions, we've got questions" Shack will more than double the cost. Have fun. Mike Burke 9/4/96 Jeff Wovkulich 119 Warren Hall Rensselaer Polytechnic Institute Troy, NY 12180