Brainstorming a new wall racer.
January 7, 2009
I'm not "officially" starting on a new bot (my husband would kill me), but Radioshack had these RC cars with hoods that popped up to show the innards for only $10, and remembering Frits' Robot Wall Racers, the temptation was too great.
I'm going to start with the RWR design, and then add more. I'm keeping this list here so that I don't forget!
rf sensor for both left and right sides.
rf sensor mounted to motor on top for forward/back detecton.
IR sensor pointing down at an angle on both front and back bumpers for detection of ledges.
lights indicating brakes and reverse.
possible horn (it can yell if it gets stuck).
Also since the motors are not servos, I might want to mess a bit around with PWM to see if I can control speed any better.
From all the sensors and drivers I want, I think I may need a second picaxe chip, which would be great, because I'm all about learning new things. One chip could be designated sensory, and the other one can be the driver.
And if I'm using two chips, I think I may still wire up the RC receiver. All it does really is push out high or low on 4 different wires, so I could use that as a type of input. Mainly, I want to have some way of getting it to stop if it runs off down the road. The remote is simple with 4 pushbuttons hidden under a flip switch to make it look "fancier". I'll just replace one of those pushbuttons with a flip switch on its own. As long as the switch is on, the remote control works. If no buttons are pressed, the RC controller immediately turns off. This way I can manually kill switch, or if the bot gets too far away, it won't sense the rc controller.
Another button could be used to go through different modes of operation. This will be for further development, as the initial setup will be quite simple with the only goal being to drive around as fast as possible without hitting anything, and without falling too far.
I think this will be a good basic bot to start off with, and once I can get this to run smoothly, we'll see where else it takes me.
Oh, and I mentioned the hood popping up because I plan to take out the "engine" and place the picaxe chips there. Easy to program with no usb/serial adapter hanging out anywhere!
Because SOMEONE(tm) was asking for pictures, here they are!
Here she is, sans ugly stickers that were all over.
To give you an idea of the size. This car looks to be a foot long.
After removing the shell. Really not much there. The tube going up is a spring that's been hooked to the antenna wire. I wonder what the range on this is!
Ignore the Billy Bass. He is a project for another time...
Let's take a look under the hood! A wonderfully fake silver painted plastic engine.
Yeah... that's gotta go.
Ahhh.... much better. Can't you just imagine a proc sitting in there?!?
Luckily the plastic for the headlights wasn't attached to the engine. I can't figure out how to get them out yet, but am planning on modifying them in order to be able to use leds.
Comparison of space inside the car. There's so much I could nearly put my whole hand inside while it was still put together!