The Program.
'**********************************************
' b0 = variable for right servo pin = 0
' b1 = variable for left servo pin = 1
' Piezo speaker pin = 2
'
' b6 = variable for right eye pin = 6
' b7 = variable for left eye pin = 7
'
'**********************************************
Symbol counter = b4 ‘ Counter
Symbol Reye = b6 ‘ Right Eye
Symbol Leye = b7 ‘ Left Eye
Symbol LwSig = b3 ‘ Low Signal of light.
'**********************************************
Init:
pins = 0 ‘ Initialize.
dirs = %00001111
LwSig = 255
gosub Start
‘ PART 1 ****** Find Bright Spot *************
‘ ******* Then Point there ************
FindHigh:
gosub spin ‘ Normal fwd speed
gosub ReadE ‘ Read eyes
counter = counter + 1 ‘ Inc. counter
if counter > 90 then Find ‘ Complete 1 spin?
if Reye = LwSig then MoreLt ‘ At bright spot?
goto ContFnd
MoreLt:
LwSig = Reye ‘ Save location of high
goto Continue
Find:
if Reye = LwSig then Follow ‘ At Bright Spot?
goto Continue
ContFnd:
gosub Pulse
goto FindHigh
‘PART 2 ********* Follow Light ******************
Follow:
gosub ReadE ‘ Read eyes
gosub Forward ‘ Normal fwd speed
if Reye > Leye then TrnRt
if Leye > Reye then TrnLt
goto Continue ‘ If eyes are equal
TrnRt:
gosub Right ‘ Cut right servo speed
goto Continue
TrnLt:
gosub Left ‘ Cut left servo speed
goto Continue
Continue:
gosub Pulse
goto Follow
'********* SUBROUTINES **************
ReadE:
pot 6,255,b6 ‘ Read right CDS cell
pot 7,200,b7 ‘ Read left CDS cell
b6 = b6 / 16 ‘ Make it smaller
bb7 = b7 / 16
return
Pulse:
b0 = 125+b0 ‘ Adjust for + = forward.
b1 = 128-b1 ‘ Adjust for + = forward
pulsout 0,b0 ‘ right servo
pulsout 1,b1 ‘ left servo
return
Forward:
b0 = 50 ‘ Normal forward speed
b1 = 50 ‘ Normal forward speed
return
Spin:
b0 = 10 ‘ Spin the bot
b1 = -10 ‘ Spin the bot
return
Right:
b0 = 2 ‘ Slow to turn right
return
Left:
b1 = 2 ‘ Slow to turn left
return
Sing:
sound 2,(60,15,75,15,90,15,60,30)
return ‘ Make a sound
Start:
gosub sing ‘ Sing a song
gosub sing
gosub sing
pause 1000
return
As you can see this code is broken into two parts. The first part of the program spins the robot 180 degrees ,
takeing a sensor reading each step. The program remebers the location of the brightest spot. After the first full
spin, the robot, the robot continues to spin until it reaches the location of the brightest spot.
The second part of the code allows the robot to follow the sensor with the brightest light on it. If the two sensors
are equal, then the robot just goes forward. It may surprise you that this code compiles down to about 100 bytes of
code space in the BASIC Stamp.