Advanced Robotics with the Toddler (Paralax, student guide, v1.3, 2004)

FREQOUT RightIRLED,1,38500 ' repeat for the right IR pair. sensors.bit1 = RightIR_SensorIn

' check if currently doing an IR move IF ((leftIR_Flag = 1) & (rightIR_Flag = 1)) THEN See_Both

IF (leftIR_Flag = 1) THEN See_Left ' is left only?

'By loading the IR detector output values into the lower 2 bits of the

'sensors

'variable, a number between 0 and 3 that the branch command can use is

'generated.

'Sensor outputs a low to indicate it saw something so BRANCH looks

'backwards.

BRANCH sensors,[See_Both,See_Right,See_Left,See_None]

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SEROUT To_Co_Proc, Baud, [LeftVisionLEDOn]

' turn on LED

SEROUT To_Co_Proc, Baud, [RightVisionLEDOn] ' turn on LED

RETURN

SEROUT To_Co_Proc, Baud, [LeftVisionLEDOn] ' turn on LED

RETURN

See_None: newMove = Fwd RETURN

'---------------

Do_Bumper:

'Bumpers on each foot. A hit causes Toddler to back and turn.

'Code asssumes leg that hit is on the leg that is moving

'(while leaning on the other leg).

'A hit backs up the hit leg right away then steps back 1 step

'and does a pivot away.

IF (leftBumpFlag = 1) THEN Bump_LeftA ' check for old bumper hit on left IF (rightBumpFlag = 1) THEN Bump_RightA

' check for old bumper hit on right

IF (LeftBumper = 0) THEN Bump_Left ' check for bumper hit on left IF (RightBumper = 0) THEN Bump_Right ' check for bumper hit on right RETURN

Bump_Left:

Bump_Right:

'DEBUG "bump right", cr

SEROUT To_Co_Proc, Baud, [StrideServoPos]

'DEBUG cr, "start NewMovemt; newMove = ", HEX newMove 'DEBUG ", currentMove = ", HEX currentMove, cr

doneMoveFlag = 1 ' stop current move wherever it is currentMove = newMove

'When customizing the program, here is where to integrate between moves.

'You can make the transitions reasonable by using the existing Mx value

'and MxOffset to compute the proper MxOffset to start into the next move.

LOOKUP newMove,[Forward,PivotLeft,PivotRight,LBumper,RBumper],Mx ' lookup movement table index

ENDIF

IF (doneMoveFlag = 1) THEN ' done moving - lookup new move in table READ (Mx + MxOffset), bMovmnt ' read next basic move byte 'DEBUG "Mx = ", HEX Mx, ", MxOffset = ", HEX MxOffset

MxOffset = MxOffset + 1

'DEBUG "SC, ", cr

Appendix C: Blue Bell Designs Co-Processor Chip · Page 223

CASE SR

newValue = RightStride

IF (doTiltFlag = 1) THEN ' only do this when the move is tilt IF (currentTilt < newValue) THEN

DelayTime = newValue - currentTilt ELSE

DelayTime = currentTilt – newValue

' coming from left tilt = decrement

ENDIF

SEROUT To_Co_Proc, Baud, [TiltServo,newValue] 'Set Servo 0 = Tilt

DelayTime = DelayTime/TiltStep CurrentTilt = newValue

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IF (currentStride < newValue) THEN

DelayTime = newValue - currentStride

ELSE

DelayTime = currentStride - newValue

ENDIF

SEROUT To_Co_Proc, Baud, [StrideServo,newValue] 'Set Servo 1 = Stride

DelayTime = DelayTime/StrideStep CurrentStride = newValue

Appendix C: Blue Bell Designs Co-Processor Chip · Page 225

By using the CycleIndicator output we can see that the Main_Program DO...LOOP now normally takes only 12 to 14 milliseconds. More to the point, it no longer matters anyway! The servos are kept moving along by the servo controllers. We now have almost the complete BASIC Stamp 2 processor back for whatever great new things we can come up with. If the program takes a while to get back to checking for the “Timer Expired” line to be complete, it just means the response to seeing or feeling something or maybe the time between moves is delayed. The smoothness of the servo movements is not sacrificed. Programming also becomes much easier and non-critical.

What other features are in the Blue Bell Design Co-Processor?

There are also six channels of 10 bit A/D. Channel 0 is permanently wired to the battery supply voltage. One of the others could be connected to the Memsic 2125 Accelerometer to allow temperature compensation from the analog temperature output. Analog outputs from IR distance sensors, temperatures, humidity, can all now be accurately measured.

There is an IR vision system and bumper sensors that can be used if BASIC Stamp I/O becomes a problem. See the data on Blue Bell Design’s website for more detailed information.

The easy way to more fun!

Tuning a processor for absolute maximum performance can be a big pain, even though it’s a standard part of any embedded process. On the other hand, with a Blue Bell Design Co-Processor, you can easily try out new and fun behaviors, added sensors, or whatever, on your Toddler. Best of all, it is available on an easily attached board for convenient installation on your Toddler! Purchase it from www.bluebelldesign.com.

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