BoeBot Ping navigation program
Eleuther
Posts: 20
Hi I was wondering if the Boe Bot were to encounter something with the Ping sensor is there a way to program the bot to randomly choose to turn right or turn left or something better? Please help thanks.
Comments
The only thing is you want to avoid an obstacle so moving randomnly may cause you to hit the obstacle
' =========================================================================
'
' File...... RoamingWithPING.bs2
' Purpose... Roam And Scan Using PING))) Mounting Bracket
' Author.... Parallax, Inc.
' E-mail.... support@parallax.com
' Started...
' Updated... 12-21-2005
'
' {$STAMP BS2}
' {$PBASIC 2.5}
'
' =========================================================================
'
[ Program Description ]
' This programs demonstrates roaming with the Parallax PING))) Mounting
' Bracket, which allows you to pan-scan with your Parallax PING))) sensor.
'
' This program assumes you have already set your BOE-Bot up for roaming
' with IR sensors. You must also have the PING))) Mounting bracket
' installed as per the instructions, with the servo connected to P14 and
' the PING))) sensor connected to P15.
'
' Due to the way the PING))) bracket mounts you may have to trim your IR
' detectors down so that they don't stick up in the way of the moving
' PING))) bracket as it rotates. It's best to angle them off at 45
' degree angles so that the BOE-Bot doesn't run into anything while
' moving along a wall at a narrow angle.
'
' The BOE-Bot will now roam around and when it senses an object, it will
' scan within a 180 degree field of view for the clearest path, which it
' will then navigate scanning for an object again. The IR Sensors prevent
' hitting a wall when coming at it from a narrow angle where the PING)))
' might have trouble seeing it due to the lack of reflection of sound.
'
' Calibration is important to this code working properly. If you do not
' have the correct values for your servos then you may get strange results
' from your BOE-Bot. The necessary calibration information is listed in
' each section of the code where it is required.
'
[ Revision History ]
' This code is basically a modified version of the Roaming With IR code
' from the Robotics With The BOE-Bot Manual, written by Andy Lindsay.
' Much of the original code was left untouched so you can see how it was
' altered.
'
[ I/O Definitions ]
Piezo PIN 4 ' Piezo Speaker
RightServo PIN 12 ' Right Servo
LeftServo PIN 13 ' Left Servo
PingServo PIN 14 ' PING))) Servo
Ping PIN 15 ' PING))) Sensor
'
[ Variables ]
pulseCount VAR Byte ' Used For Measuring Turns
distance VAR Word ' Current Distance Of Object
oldDistance VAR Word ' Old Distance Value
counter VAR Word ' PING))) Cycle Counter
task VAR Nib ' button input
flip VAR Word ' a random number
coin VAR flip.BIT0 ' Bit0 of the random number
trials VAR Byte ' number of flips
Left VAR Byte ' throws that come up heads
Right VAR Byte ' throws that come up tails
btnWrk VAR Byte
'
[ Initialization ]
FREQOUT Piezo, 300, 2000
PAUSE 10 ' Signal Program Start/Reset
FREQOUT Piezo, 300, 1500
PAUSE 10
'
[ Program Code ]
DO
counter = counter + 1 ' Increment Passive Counter
IF counter > 5 THEN ' Wait For 10 Servo Pulses
GOSUB Ping_Out ' Activate PING)))
ENDIF
IF (distance > 1) THEN
RANDOM flip
ELSEIF Left THEN
GOSUB Turn_Left
ELSEIF Right THEN
GOSUB Turn_Right
ELSE
GOSUB Forward_Pulse ' Otherwise Scan For Clear Path
ENDIF
LOOP
'
[ Subroutines ]
' *************************************************************************
' * USE THE APPROPRIATE PULSOUT VALUES TO MAKE YOUR BOE-BOT MOVE FORWARD *
' * WHILE THE PING))) IS FACING FORWARD. *
' *************************************************************************
Forward_Pulse: ' Send A Single Forward Pulse
PULSOUT PingServo, 690 ' Ping Servo Forward Pulse Value
PULSOUT LeftServo, 850 ' Left Servo Forward Pulse Value
PULSOUT RightServo, 650 ' Right Servo Forward Pulse Value
PAUSE 20 ' Refresh Delay
RETURN
' *************************************************************************
' * USE THE APPROPRIATE PULSOUT VALUES TO MAKE YOUR BOE-BOT TURN LEFT 90 *
' * DEGREES. USE THE SAME VALUE AS ABOVE FOR THE PING))) BRACKET SERVO. *
' *************************************************************************
Turn_Left: ' Left Turn, About 45 Degrees
FOR pulseCount = 0 TO 1 ' Number Of Pulses To Turn
PULSOUT PingServo, 840 ' Ping Servo Forward Pulse Value
PULSOUT LeftServo, 650 ' Left Servo Left Pulse Value
PULSOUT RightServo, 650 ' Right Servo Left Pulse Value
PAUSE 20 ' Refresh Delay
NEXT
RETURN
' *************************************************************************
' * USE THE APPROPRIATE PULSOUT VALUES TO MAKE YOUR BOE-BOT TURN RIGHT 90 *
' * DEGREES. USE THE SAME VALUE AS ABOVE FOR THE PING))) BRACKET SERVO. *
' *************************************************************************
Turn_Right: ' Right Turn, About 45 Degrees
FOR pulseCount = 0 TO 1 ' Number Of Pulses To Turn
PULSOUT PingServo, 460 ' Ping Servo Forward Pulse Value
PULSOUT LeftServo, 850 ' Left Servo Right Pulse Value
PULSOUT RightServo, 850 ' Right Servo Right Pulse Value
PAUSE 20 ' Refresh Delay
NEXT
RETURN
' *************************************************************************
' * USE THE APPROPRIATE PULSOUT VALUES TO MAKE YOUR BOE-BOT MOVE BACKWARD *
' * WHILE THE PING))) IS FACING FORWARD. *
' *************************************************************************
Back_Up: ' Back Up
FOR pulseCount = 0 TO 40 ' Number Of Pulses To Backup
PULSOUT PingServo, 750 ' Ping Servo Forward Pulse Value
PULSOUT LeftServo, 650 ' Left Servo Backup Pulse Value
PULSOUT RightServo, 850 ' Right Servo Backup Pulse Value
PAUSE 20 ' Refresh Delay
NEXT
RETURN
Ping_Out: ' PING)))
counter = 0 ' Reset Passive Delay Counter
LOW Ping ' Force PING))) Line Low
PULSOUT Ping, 5 ' Activate PING))) Pulse
PULSIN Ping, 1, distance ' Receive Return Pulse
distance = distance ** 2257 ' Calculate Distance
RETURN
Ping_Around: ' Start 180 Degree Pan-Scan
counter = 0 ' Reset Passive Delay Counter
oldDistance = 30 ' Current Old Distance Values
task = 0
' Current Task Priority
' *************************************************************************
' * USE THE APPROPRIATE PULSOUT VALUE TO MAKE YOUR PING))) *
' * TURN 90 DEGREES LEFT. *
' *************************************************************************
FOR pulseCount = 0 TO 20 ' Number Of Pulses To Spin
LOW Ping ' Force PING))) Line Low
PULSOUT PingServo, 1085 ' Ping Servo 90 Left Pulse Value
PULSOUT Ping, 5 ' Activate PING)))
PULSIN Ping, 1, distance ' Receive Distance Value
PAUSE 20 ' Refresh Delay
NEXT
distance = distance ** 2257 ' Calculate Distance In cm
IF distance > oldDistance THEN ' Is distance > Last Clear Path
oldDistance = distance ' Update oldDistance Value
task = 1
ENDIF
' *************************************************************************
' * USE THE APPROPRIATE PULSOUT VALUE TO MAKE YOUR PING))) *
' * TURN 45 DEGREES LEFT. *
' *************************************************************************
FOR pulseCount = 0 TO 20 ' Number Of Pulses To Spin
LOW Ping ' Force PING))) Line Low
PULSOUT PingServo, 850 ' Ping Servo 45 Left Pulse Value
PULSOUT Ping, 5 ' Activate PING)))
PULSIN Ping, 1, distance ' Receive Distance Value
PAUSE 20 ' Refresh Delay
NEXT
distance = distance ** 2257 ' Calculate Distance In cm
IF distance > oldDistance THEN ' Is distance > Last Clear Path
oldDistance = distance ' Update oldDistance Value
task = 2
ENDIF
' *************************************************************************
' * USE THE APPROPRIATE PULSOUT VALUE TO MAKE YOUR PING))) *
' * TURN 45 DEGREES RIGHT. *
' *************************************************************************
FOR pulseCount = 0 TO 20 ' Number Of Pulses To Spin
LOW Ping ' Force PING))) Line Low
PULSOUT PingServo, 400 ' Ping Servo 45 Right Pulse Value
PULSOUT Ping, 5 ' Activate PING)))
PULSIN Ping, 1, distance ' Receive Distance Value
PAUSE 20 ' Refresh Delay
NEXT
distance = distance ** 2257 ' Calculate Distance In cm
IF distance > oldDistance THEN ' Is distance > Last Clear Path
oldDistance = distance ' Update oldDistance Value
task = 3
ENDIF
' *************************************************************************
' * USE THE APPROPRIATE PULSOUT VALUE TO MAKE YOUR PING))) *
' * TURN 90 DEGREES RIGHT. *
' *************************************************************************
FOR pulseCount = 0 TO 20 ' Number Of Pulses To Spin
LOW Ping ' Force PING))) Line Low
PULSOUT PingServo, 225 ' Ping Servo 90 Right Pulse Value
PULSOUT Ping, 5 ' Activate PING)))
PULSIN Ping, 1, distance ' Receive Distance Value
PAUSE 20 ' Refresh Delay
NEXT
distance = distance ** 2257 ' Calculate Distance In cm
IF distance > oldDistance THEN ' Is distance > Last Clear Path
oldDistance = distance ' Update oldDistance Value
task = 4
ENDIF
ON task GOSUB Task0, Task1, Task2, Task3, Task4
distance = 50 ' Prevent Scan From Looping
RETURN
Task0: ' Forward Was Clearest Path
GOSUB Turn_Right ' This Could Mean Narrow Path
GOSUB Turn_Right ' So We'll Turn Around
GOSUB Turn_Right ' You Can Change The Behavior
GOSUB Turn_Right ' Of Any Of The Tasks
RETURN
Task1: ' 90 Degrees Left Was Clearest
GOSUB Turn_Left
GOSUB Turn_Left
RETURN
Task2: ' 45 Degrees Left Was Clearest
GOSUB Turn_Left
RETURN
Task3: ' 45 Degrees Right Was Clearest
GOSUB Turn_Right
RETURN
Task4: ' 90 Degrees Right Was Clearest
GOSUB Turn_Right
GOSUB Turn_Right
RETURN
How is it working? Do you like how the robot behaves?
I added an ultrasound sensor to my Scribbler 2. I also wondered about adding some sort of S turns so it didn't have to stop to look for an openning. One more thing to add to robotics todo list (which includes a robot todo my todo lists).
BTW, it's a lot easier to read code if you use code blocks. Here's link to a tutorial by Phil.