Low-Cost, super simple robot you can build yourself in a weekend.

This robot was inspired by my original attempts to build a "dog" bot.

What makes this neat is that it is simple to build AND it is expandable. Expanding is done by changing to a larger processor.

I`m building another version of the little control board using the picAxe 18x just to give myself more program space to make the thing behave simply.

I wanted to use the continuous motion servos I found on sale at Fry`s for 10 bucks. I had read a lot about the famous (at least to me): Boe Bot, which used continuous motion servos for driving. It would run slow at top speed, but I knew this would make it work even better without worrying about stopping as soon as it sees an obstacle.

I also liked the - servo head setup I used on the original Robo Dog I called dogbot which is written up somewhere else on this site. Dogbot had very "living animal" type head moves and I wanted to implement that same functionality in this little black box version of a Boe-Bot style DogBot.

` ------------------------------------------------------------
` Select and initialize chipset
` ------------------------------------------------------------
#picaxe 14m
` System resources
symbol serialOut = 0 `(pin 13) o0, serialOut
symbol leftDrive = 1 `(pin 12) o1
symbol rightDrive = 2 `(pin 11) o2
symbol UpAndDown = 3 `(pin 10) o3 servo Vertical
symbol SideToSide = 4 `(pin 9) o4 servo Horizontal
symbol Piezo = 5 `(pin 8) o5 D
symbol ADCin0 = 0 `(pin 7) i0 C lightSensor
symbol i1 = 1 `(pin 6) i1 B
symbol i2 = 2 `(pin 5) i2 A IRsensor
symbol i3 = 3 `(pin 4) i3
symbol ADCin4 = 4 `(pin 3) i4
symbol srlIn = 2 `(pin 2) i5
` (pin 1 Vdd, pin 14 = Vss)


` ------------------------------------------------------------------
` Application dependant values
` ------------------------------------------------------------------
` register vars
symbol side2sideCnt = b0 `= w0
symbol upNdownCnt = b1 `= (w0)
symbol xCount = b2 `= (w1)
symbol yCount = b3 `= (w1)
symbol lrRangeRight = w2
symbol lrRangeLeft = w3
symbol IRstor = w4 `= temporary IR reading
symbol maxStor = w5 `= w5
symbol xStor = b12 `= w6
symbol yStor = b13 `= (w6)

symbol minSideToSide = 30 `rightest
symbol ctrSideToSide = 118 `center Side to Side
symbol maxSideToSide = 200 `leftist

symbol minUpAndDown = 100 `uppest
symbol ctrUpAndDown = 140 `head at middle
symbol maxUpAndDown = 155 `lowest

symbol servo_delay = 40 `Delay to slow down servo motion (40ms default)
symbol adc_delay = 1 `Let ADC settle (can be 1 or 0)


` ------------------------------------------------------------------
` Application initialization
` ------------------------------------------------------------------
disablebod `make sure it works with low battery

init:
` beep
tune Piezo, 8,($47,$4A,$47)
low Piezo `release timers on chip
` The all important "Bail Out" pause - gives you time to clear hardware memory
pause 100

gosub ctrHead
pause 300

gosub snoop
pause 200
gosub ctrHead

setint %00000001,%00000001

` ------------------------------------------------------------------
` Drive Around loop
` ------------------------------------------------------------------
runAround:
servo leftDrive, 140
servo rightDrive,80
pause 500
goto runAround


interrupt:
gosub drive_stop_all

` beep
tune Piezo, 6,($4A,$4A,$4A)
low Piezo `release timers on chip

gosub ctrHead

servo leftDrive, 140 `move fwd
servo rightDrive,80
pause 200 ` fwd only a smidgeon to find a way out

gosub drive_stop_all
gosub snoop

setint %00000001,%00000001
return

snoop:
maxStor = 0
xStor = 118
setint %00000000,%00000000 `stop interrupts so you can do measurements
for side2sideCnt = minSideToSide to maxSideToSide step 20
servo SideToSide, side2sideCnt
pause 90
` Check here for signals from sensor
readadc10 ADCin0, IRstor
pause adc_delay ` what is the value now in IRstor??
if maxStor < IRstor then `take a moment to:
maxStor = IRstor `remember the closest object value
xStor = side2sideCnt `remember the x-coordinates
yStor = upNdownCnt `remember if it`s tall or short
endif
next side2sideCnt
servo SideToSide, ctrSideToSide
pause 500
if xStor < 118 then ` object right
gosub turnLeft
endif
if xStor > 118 then ` object left
gosub turnRight
endif
pause 400 ` turn time (tune for carpet-hard floors)
return

`-----------------------------------------------------------------------
` head control
` shakeHeadNo
shakeHeadNo:
servo SideToSide, minSideToSide
pause 100
servo SideToSide, ctrSideToSide
pause 100
servo SideToSide, maxSideToSide
pause 100
servo SideToSide, ctrSideToSide
return

`-----------------------------------------------------------------------
` head control
` ctrHead

ctrHead:
servo SideToSide, ctrSideToSide
pause 200
servo UpAndDown , ctrUpAndDown
pause servo_delay
pause 300
low SideToSide ` use only when you need to save current
low UpAndDown
return


`-----------------------------------------------------------------------
` motor control
` Reverse
tryReverse:
servo leftDrive, 80
servo rightDrive,140
return

`-----------------------------------------------------------------------
` motor control:
drive_stop_all:
servo leftDrive , 128
servo rightDrive , 128
pause servo_delay
low leftDrive
low rightDrive
return


`-----------------------------------------------------------------------
` turn right
turnRight: `right 140, left 80
servo leftDrive, 140
servo rightDrive,140
return

`-----------------------------------------------------------------------
` turn left
turnLeft: `right 140, left 80
servo leftDrive, 80
servo rightDrive,80
return

I did some experiments with giving the Black Box a Skin. While this one could be better, it gives you an idea of what you can do