Hi,
I'm wondering how to design a kind of "laser combat" between RC robots. Something working like lasertag games.
I was thinking to use laser emitters and sensors (like the KY-008 shields or similar ones) but reading the descriptions normally provided by the manifacturers, it seems that the sensors are sensible to daylight too, and using them in dark environment is recommended.
I was thinking about a laser based system because the IR emitters have a wide angle (too wide for my purposes, as the target is small, let's say kitten-size ) and I would risk to get false positive results from the target sensor, I'm afraid.
Today I was looking at this video, where an emitter and its sensor have been tested outdoor (not in full sunlight, actually, but it's still a nice daylight) and they seem to work well, regardless of the environmental light: $3 laser transmits audio over 100m (arduino) - YouTube
Does anyone have more informations and/or direct experiences with these sensors and if/how much they are actually influenced by daylight? (and so, eventually how to solve this problem)
The sunlight and other light problems are avoided by modulating your laser and looking for that modulation frequency in the receiver. Exactly like IR remote control devices do it.
Modulation as stated is the way to go. You should also use a PLL (Phase Locked Loop) chip, a LM565 would be a good starting place.
Good Luck & Have Fun!
Gil
Paul_KD7HB:
other light problems are avoided by modulating your laser and looking for that modulation frequency in the receiver. Exactly like IR remote control devices do it.
I've excluded IR modules due to their wide angle of emission which could even be good for human-played lasertag games, and it's not so important if the head or other parts of the body have been hit, i.e. it doesn't really matter where the receiving sensor is located on the player's body. Here I plan to have small robots, like RC cars or tanks, and I don't want a sensor to be activated because a 10 mt distant "enemy" is just pointed in the right direction and it fires a wide "cone" signal that always hits the target like a TV rc that just works as soon as is generically pointed toward the TV.
Anyway, I've found this library, that seems to use exactly the KY-008 shields, do you think it could be good for this purpose?
BTW, such of modulation could also be used to identify the shooting robot, giving it any kind of ID code and using that code as the modulated message transmitted when the laser is shot? I wasn't planning a team based game (where a precise identification of who's shooting at whom is strictly required) but it can be useful anyway, at least for logging needs.
gilshultz:
You should also use a PLL (Phase Locked Loop) chip, a LM565 would be a good starting place.
I'm pretty noob with electronics and at this stage I'm still trying to figure out what I could do and how. I'm going to read something about PLL and how to use them, but can you address me to any useful (and noob-comprehensible) reference or explanation?
Before you do any more thinking about using a laser for anything like your project, do a lengthy study on safety while using lasers. Your eyesight and anyone around you may have damage from your experiments, even by reflections.
My problem with IR devices has so far been the very small field of vision... just a few degrees bream spread. IR LEDs as used in remote controls indeed have a very wide spread.
Look at break beam sensors, they may offer pretty narrow beams without the intensity of a true laser. Many of those also use modulated IR so are not too affected by daylight, but in full sunlight they may still be saturated and stop working.
) and I would risk to get false positive results from the target sensor, I'm afraid.