Cricket (Handy Cricket)

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Cricket (Handy Cricket)

• Kyeongseo Hwang (Mike)
• Nicholas Ver Hoeve

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Agenda

• About Cricket (HW)
• History of Logo (Built in interpreter)
• Intro to Cricket Logo
• Demo

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About Cricket
LIGHT SENSOR
TOUCH SENSOR
MAG. REED SWITCH
IR SENSOR
DC MOTOR
BREAK BEAM SENSOR
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History of Logo

• Logo Developed in BBN (a Cambridge University
  research firm), in 1966
• By Seymour Papert, Wally Feurzeig
• Modeled after LISP
• Now in multiple dialects ExperLogo, ARLogo, MIT
  StarLogo, NetLogo, etc.
• Cricket Logo developed in MIT by Brian Silverman
  with Fred Martin beginning in 1995

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Intro to Cricket Logo

• Procedure definition with inputs and return
  values
• Global variables and local procedure inputs
• Control structures if, repeat, and loop
• 16-bit number system addition, subtraction,
  multiplication, division, remainder, comparison,
  bit-wise operations, random function
• Motor and sensor primitives
• Timing functions and tone-playing functions
• Data recording and playback primitives
• IR Communications primitives

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Intro to Cricket Logo
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Motor Command

• a, Motor A
• b, Motor B
• ab, Motor A and B
• on Selected motor On
• off Selected motor Off
• onfor Selected motor will turn on
  for /10 secs.
• thisway/ thatway Sets direction
• rd Reverses the direction
• setpower set power level

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Sensor Command

• switcha
• return 1 if switched plugged into sensor A is
  pressed
• switchb
• return 1 if switched plugged into sensor A is
  pressed
• sensora
• Report the value of sensor A 0255
• sensorb
• Report the value of sensor B 0255

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Timing and tone-playing

• Timing
• ab, on wait 20 off
• ab, onfor 20
• wait
• timer
• resett
• Tone-playing
• beep
• note 110 30
• www.handyboard.com/cricket/program

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Control Structures

• repeat times body
• loop body
• if condition body
• ifelse condition body-1 body-2
• waituntil condition
• stop(!)
• output returning_value

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Numbers

• 16 bit number system
• -32768 32767
• All arithmetic operators separated by a space
• 3 4
• Normal expression precedence rules are not used,
  evaluated left to right
• 3 5 7 ?
• (3 (4 5)) ?

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Number Operator (cont)

• Infix addition
• - Infix subtraction
• Infix multiplication
• / Infix division
• Infix modulus (remainder after integer
  division).
• lt Infix LESS-THAN test.
• Results in 1 if left-hand value is less than
  right-hand value 0 otherwise.

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Number Operator (cont)

• gt Infix GREATER-THAN test. Results in 1 if
  left-hand value is greater-than than right-hand
  value 0 otherwise.
• Infix equality test.
• Results in 1 if left-hand value is equal to
  right-hand value 0 otherwise.
• and Infix AND operation (bitwise).
• or Infix OR operation (bitwise).
• xor Infix exclusive-OR operation (bitwise).
• not prefix NOT operation (logical inversion,
  not bitwise).
• random Reports pseudo-random number from 0 to
  32767.
• Use the modulus operator to reduce the range
  e.g., (random 100) yields a number from 0 to 99.

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Procedure Definition with input

• to flash1
• repeat 10 a, onfor 5 wait 5
• end
• to flash2 n
• repeat n a, onfor 5 wait 5
• end
• global temp
• to detect
• settemp sensora
• if temp lt 30 output 1
• if temp lt 50 output 2
• output 3
• end

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Variables

• Global variable
• global variable-list e.g. global cat dog
• Stored in RAM -gt data recording and playback
  functions
• Integer only
• Global-setting primitive
• setcar, setdog e.g. setcat 3 setcat cat 1
• Global Array
• array clicks 10 clacks 15
• Array indices start at 0
• aget name index
• aset name index
• No buffer-overrun checking
• Stored consecutively in memory
• stored in the Cricket's non-volatile memory

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Data Recording and Playback

• to take-data
• resetdp repeat 2500 record sensora wait 10
  
• end
• resetdp
• setdp position
• erase
• record value
• Recall

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Recursion

• to fact n
• if n 1 output 1
• output n fact n 1
• end -gt repeat fact 3 beep
  wait 1
• Normal Recursion has uncertain max depth, can be
  as low as 5
• Supports Tail Recursion
• converting the recursive call into a goto
  statement
• to beep-forever
• beep wait 1
• beep-forever
• end

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Multi-Tasking

• supports a limited form of multi-tasking
• One background task
• repeatedly checks a condition
• When true it interrupts and processes
• when switcha beep loop a, onfor
  5 rd
• only one background task operating at any given
  time.
• If a when statement is executed after the
  background task has already been started, the
  subsequent when task supercedes the earlier one
• To stop the background task from operating, use
  the primitive whenoff.

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Samples

• Files at www.cs.rit.edu/kxh7583/PLC/
• Demo the multi-taking
• IR communication between crickets
• Background Operation

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Reference

• www.handyboard.com/cricket
• http//gleasonresearch.com/ http//lcs.www.media.m
  it.edu/people/fredm/projects/cricket/redlogo.html
• http//www.papert.org/
• http//www.mathsnet.net/logo/turtlelogo/