I want to make 2 robots out of Lego with tank treads and a turret that will shoot an "Ion Cannon" at the other bot. When hit, the bot will rock its wheels, make a sound and a point given to the victor. I want these to battle in an arena of fish tank gravel, and the turrets only will have left-right degrees of freedom in a maximum of a 180 degree spread (powered by a servo)
My question is, that if I use IR transmitter/receivers for the cannon and sensor on the bots, even if I collimate the IR sensors inside a tube, has anyone got any experience if this is going to hit the target too easily due to the wideness of the beam of IR. (That is what they are designed for in TV remote applications, after all)
I thought about using a laser pointer and photocell, but since I don't want to employ 2 axis movement on the turret and my arena will not be level, I didn't think a beam of that narrowness would be the best choice.
The point of this is to take it to schools, fairs and conventions to teach kids about robotics and coding -- I'm doing it for my senior project at college. So it has to work well, if I'm going to get kids at the helm, battling it out!
Perhaps I get a beam collimator 3d printed with a tall narrow opening like a slit, so the beam is wide vertically but narrow horizontally?
Second, how wide is the sensor portion on the receiving end? I wonder how many sensors I should put on each tank - I was hoping to only need one in front and back.
More details:
I'll be using Spark Photons for the Arduino brains, and sending the commands to the bots via wifi on a simple web application that looks pretty cool. I'll either host the app on my site or directly on Raspberry Pi's and then let the kids just use keyboards to control them with cheap LCD monitors with the Pi mounted on the back. Depending on latency and connectivity - I need to find out if the Sparks require an internet gateway, or if I can control things locally with a cheap router but no gateway.
Chassis will be built *hopefully* using only 2 Lego technic sets, $17 each. I'm halfway through prototyping and I'm going to buy a second copy of the same set, to get needed pieces. Tread will be driven by hacked servos into 360 degree servos, using 3d printed adapters. Boards will probably just be attached with the good old zip tie. Turret cable will just run down and I'll do my best to make sure it doesn't get pinched. I want to cheapify this project as much as possible, because I'm planning to open source it, and I'd like it to be within the means of schools directly. (Mindstorms is really spendy)
Power is going to be a cheap on the go style USB charger from the big box store. I'm working on calculating power requirements. 3 servos, an IR led, 2 IR receivers and the Spark are all I have now, but I'm going to make the platform scalable for line followers, Ping sensors etc. Eventually, I could have an AI bot that one could play against solo. Also, FPV video feeds would be really cool, but I need to get the system off the ground in version 1.