TreadBot

[mackrackit]

"i didnt know computer mouses had balls???"

That is how you tell the difference, male or female... You really are a NEWBIE

The ball and optos could mount on a spring loaded platform in the front or back.

This is an interesting problem, in my work we use doppler radar along with gps for applicators that move across the field at 20 mph. Even then things could end up depending on plowed or disked - satellite coverage - etc- 50 cm off in a couple of km.

Run a "female" mouse over paper with lines and you will see the problems with that. I bet the RF idea with beacons would be the most accurate.

If I think of something very small and cheap will let you know.

[skimask]

Awhile back I had an idea for tracking a push type lawn mower.
I'd put IR LED transmitters in the 4 corners of a square lot, each with it's own pulsing IR code. On the top of the mower would be an IR detector that could move 360 degrees. I slowly go 'round until I saw 1 of the IR LEDs, mark that angle, and keep going until I saw at least 2 of the 4 IR transmitters. As long as I had two angles to work with, I could triangulate my position inside the square lot (ignoring the fact that there are really 2 places an object could be in 2D space using that method, one inside the square, one outside). The more the IR LED transmitters, the better the accuracy, and the better the chances I'll see them if the platform was to somehow get off level.

[dragons_fire]

yup im a newbie... im also almost to young for that kinda stuff!!! haha

it doesnt have to be perfect, its just for fun.,.. im thinking that although i love the size of this thing, it might be a tiny bit too small for experimenting with all this stuff...

Skimask, thats exactly the same thing i was talking about.. haveing a bunch of base stations around, that all emit different pulses, and have the robot decode that, and triangulate where it is...

im hoping i can fit everything into the pic now.. im using the 18f6585 because it had the specs i wanted for another project that fell through... so mow i have it left over, and would like to use it...

heres the specs:
48 k bytes 24 k words
1024 eeprom
53 i/o 12adc

i would just like to say, you guys have all been great. i have been on some other forums (mostly for other stuff like offroading and RC stuff) and people just tell you that there is only one way to do things, and that it wouldnt be worth the effort to attempt to do certain things..

[skimask]

it doesnt have to be perfect, its just for fun.,.. im thinking that although i love the size of this thing, it might be a tiny bit too small for experimenting with all this stuff...

Well, you could always go vertical with the PCBs, stack them with interconnecting header pins for power and use some IR emitter/detector pairs to communicate data, or whatever...then again, that might make the thing too tall to go under stuff...

Skimask, thats exactly the same thing i was talking about.. haveing a bunch of base stations around, that all emit different pulses, and have the robot decode that, and triangulate where it is...

Might be a bit of an MCU intensive process, might involve floating point math, then again, might be able to make it 'just good enough' and not 'perfect'.

As far as the PIC goes, the only thing I see limiting is program space. And when that happens, you could do what I said earlier, offload some processing to a daughterboard vertically stacked.

This almost sounds like too much fun! I outta be building one myself...as soon as my 'lab' in the basement gets done.

[dragons_fire]

right now (without the PCB and components) it will fit underneath 3/4 of the doors in my house!!! the only think that could stop it is stairs!!!

I was thinking i could stack the boards 2 or 3 high, and that would give lots of room for all the sensors and other "gadgets" that i would like to add.. It would also be a lot smaller if i went with all SMT stuff and make everything myself instead of using prebuilt components. at the moment in designing it to use a serial motor driver, which uses a 9-pin header, a pic12f629 and a dual h-bridge chip. if i put the h-bridge directly on my board, and ran it off of the 18f6585, it would be tiny... at the moment, im using it for simplicity, it uses a 4byte command to control direction and speed or both motors.

With the mapping, i was thinging of doing it somewhat like a micromouse would. the room would be divided into little squares, and then it would decide which squares it can go in, and which ones it cant..

i would like to make a list of different "missions" for robots, not just for me, but for anyone else that just plays around with this stuff. to start, here are some of the things im working on, and some others that i would like to make someday:
workin on:
house mapping
cave exploring - lots of old mines around my place
snowplow

others:
photophobic
phottropic
lawnmower
sumo competition
micromouse
firefighting
minesweeping

if anyone has any others, lets hear them... im sure there are lots of other things out there...

[dragons_fire]

this is a neat idea, a little expensive for hobby robotics though....

http://www.robotshop.ca/home/product...ar-system.html

[mackrackit]

this is a neat idea, a little expensive for hobby robotics though....

http://www.robotshop.ca/home/product...ar-system.html

Looks similar to Skimask idea, I was going to suggest sonar also. I have a cheap sonar measuring tape that is pretty accurate. Use two to have a location.

Let us know what you plan to use and we will see if we can help.