An example is the TSOP7000 IR Receiver from
Vishay Semiconductors.
Reynolds Electronics (www.rentron.com) is a source for components and modules
for IR data links. The Fyre-Fly module contains an IR transmitter and
receiver that use a 455 kHz carrier. The module has an RS-232 interface and
Going Wireless
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can transmit at up to 38,400 bps over distances of up to 80 ft. A pair of these
modules can replace an RS-232 serial cable.
Some IR systems don??™t use a carrier and instead encode each logic-0 bit as a single
pulse. To save power, the encoder can transmit pulses that are shorter than a
full bit??™s period. For example, Microchip Technology??™s MSC2120 infrared
encoder/decoder uses pulses that are less than 20% of the bit width.
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The Infrared Data Association (IrDA) defines a hardware interface and protocols
for IR communications over distances of up to 1 meter. The limited distance
makes IrDA suitable mainly for communicating with nearby peripherals.
The IrDA specifications define several physical layers that each specify a format
for transmitted data. The Serial IrDA (SIR) physical layer supports transmitting
asynchronous data at up to 115,200 bps.
1-
For longer distances or when a light of sight isn??™t available or practical,
radio-frequency (RF) communications are an option.
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RF communications must comply with government regulations.
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