Build yourself a fun obstacle avoiding robot that drives around all by itself, exploring new territories and managing to keep itself out of trouble.

This project uses just the base in a very simple robot which runs around. It proves how nice the little Rumble Bots work as a Robot Base.

You can make yours look prettier by incorporating the old head into the design. See http://www.dinofab.com/rumblebot.html for his Rumble Bot conversions. He`s done a few more than I have.

They can be found in second-hand stores. Mine cost $4 because I didn`t wait till Tuesday (1/2 price day :-)

Bottom line, when you take it apart you will find it is divided into two parts.

Remove the top. You can use it later if you want to do like Dean Segovis, who controls his Bot with an Arduino, sending pulses straight into the mother board. You don`t even have to fiddle with anything. Follow Deans instructions on his website to take things apart.

The key to the whole thing is the transmission and the motors in my version. But this is all about experimenting.

You`ll have to get your hands on a picAxe motor driver PC board (under $20) and you really ought to get a picAxe 08m for less than $4... Programming is easier and the Bot will work better... (like in the video).

Now let an IR detector module drive the 8m`s interrupt node and tell the software to go till it get`s an interrrupt, then avoid the obstacle causing the problem.

In the video, the thing first turns slightly just to whiz around things, but if the obstacle is still there, the software stops then backs up and makes a larger (90 degree) turn to totally avoid objects.

Here is the simple listing for an 08m driving the Bot Body around... You can see, it goes forward and simply moves forward till something gets in it`s way.
++++++++++++++++++++++++++

` Initialize System Wide Values
`
` Directives
` Select and initialize chipset
#picaxe 08m
`
` System resources
symbol fwdM1 = 0 `(pin 7)(Careful, Used in Programming)
symbol revM1 = 1 `(pin 6)
symbol revM2 = 2 `(pin 5)
symbol IRsense = 3 `(pin 4)(input only on 8 pin)
symbol fwdM2 = 4 `(pin 3)
` (pin 1 Vdd, pin 8 = Vss, pin 2 = Serial In)
`
` Motor Control constants
` assumptions:
` open means no output
` trying not to use external chips, only 3904s (4 outs)
` using a single sensor with dual IR emitters
` motors are M1 and M2 (cheapies from Avoider Robot)
` powered by 3x 1.2v liIon (use button batteries?)
`
` vars
symbol storResult = w2 ` place to put ADC10 results
symbol storResShrt= b4 ` place to put adc results
`
`
`--------------------------------------------------------
` Code Blocks:
`
let dirs = %00010111
` short wait before main routine begins
setint %00001000, %00001000
`
` main demo routine

`It goes like this
` gosub (fwd,rev,leftspin,rightspin)
` pause - long as you want it to do the appropriate subroutine
` gosub stopAll - You have to stop it from driving, don`t forget this
` That`s how you make the world go round
`
init: `gosub fwd `basically, you make it go, then you pause for running time
`obviously, an interrupt loop makes it quit driving anytime
gosub stopAll `don`t forget to stop the action you put in motion
pause 3000 `think and abandon all hope loop

main: gosub fwd
pause 50
goto main


interrupt:
`if pin3=1 then interrupt
gosub stopAll
pause 20 `think a second little machine :-)
gosub iSpy
setint %00001000, %00001000
return


` Look to see if a spot is clear, then head in that direction
iSpy:
gosub rev
pause 600
gosub stopAll
gosub leftSpin
pause 700
gosub stopAll
if pin3 = 1 then `still in trouble that way
gosub leftSpin ` call yourself until you`re out of trouble
pause 300
gosub stopAll
pause 100
if pin3 = 1 then `still in trouble that way
gosub rev
pause 300
gosub stopAll
gosub rightSpin ` call yourself until you`re out of trouble
pause 400
gosub stopAll
pause 100
return
endif
endif

return ` found a hole - start driving again


`-----------------------------------
` Drive Routines
`
fwd:
high fwdM1, fwdM2
pause 30
return

rev:
high revM1, revM2
pause 30
return

stopAll:
low fwdM1, fwdM2, revM1, revM2
pause 30
return

leftSpin:
high fwdM1
high revM2
pause 30
return

rightSpin:
high revM1
high fwdM2
pause 30
return