inside the handy cricket
TRANSCRIPT
1
Inside the Handy CricketFred Martin
Overview
• Origins and Status of CricketTechnology
• Cricket Hardware• Cricket Firmware and Compiler• Cricket Bus
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Origins and Status• Developed by Brian Silverman and Fred
Martin at MIT Media Laboratory• Have license to all code, designs up to
Aug 2000• Through Gleason Research, distributing
Handy Crickets & more• Publishing APIs• MIT continuing work as well
Handy Cricket Chip BlockDiagram
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The Handy Cricket
2 DC MotorOutputs
2 SensorInputs
Run/Stop Button& LED
2 Bus PortsPiezoBeeper
IR Comms
PowerSwitch 4Kbyte Memory
Cricket Software
• Virtual Machine resident in Cricket Chip(written in PIC assembly)
• Logo compiler running on workstation(written in Java)
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Cricket Logo Compiler• Translates user
Logo into VMbytecodes
• Interactive“Command Center”
• Buffer for editingand definingprocedures
Cricket Logo VM Primitives
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Compiler Examples
Cricket Bus System
• “One-Wire” comms with 1-master,multiple-slaves protocol
• Send and receive can be easilyimplemented with any micro
• Bundle device-specific driver code withHW in device itself
• Allow arbitrary expansion capability
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Handy Cricket Bus Jack
Bus Signal
• Long start bit allows receiver to sync• Data bits just 10 µs long• 9th bit indicates command or data