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TITLE
Newton MessagePad: Infrared Specifications
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Article ID:
Created:
Modified:
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16710
11/8/94
1/22/98
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TOPIC
What protocol scheme is used on the Newton MessagePad? I want to develop an application that uses the Infrared beam.
DISCUSSION
The following documents the general scheme used for Newton MessagePad units built for the United States:
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Communication Scheme: Bi-directional half-duplex
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Modulation Type: Amplitude shift keying (ASK) carrier = space, no carrier = mark
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Carrier: Infrared (900-1050 nm), 1000nm peak sensitivity
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Transmission Rate: 38,400 bps(max), under SW control, fall back to19,200 bps when error rate becomes too high. (Sharp module specified to 19.2)
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Transmission Modulation Frequency: 500kHz & 38 kHz
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Receive Modulation Frequency: 500kHz only
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Communication Range: 8 cm - 1 meter @ 19.2 kbps
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Emission directional cone +/- 13 degrees
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Receive directional cone +/- 13 degrees
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