28139 Parallax Inc, 28139 Datasheet - Page 174

• Manufacturer Part Number: 28139
• Description: KIT REMOTE IR FOR BOE-BOT W/TEXT
• Manufacturer: Parallax Inc

Specifications of 28139

• Accessory Type: IR Remote
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: Boe-Bot®
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant

How IR Communication Works
The universal remote sends messages by strobing its IR LED at 38.5 kHz for brief
periods of time. The actual data is contained in the amount of time each strobe lasts.
There are many different IR protocols, but, in general, the amount of time each 38.5 kHz
signal lasts transmits some kind of message. One duration might indicate the start of a
message, while another indicates a binary-1, and still another indicates a binary-0.
The IR detector's output pin sends a low signal while it detects the 38.5 kHz IR signal,
and a high signal while it does not. So, a low signal of one duration might indicate the
start of a message, while another indicates a binary-1, and still another indicates a binary
0. This communication scheme is called pulse width modulation (PWM), because when
graphed against time, the IR detector's high/low signals form pulses of different widths
that correspond to their durations.
Kit Contents*
Infrared Remote Parts List:
(1) 020-00001
(1) 350-00014
(1) 150-02210
(1) 800-00016
*Two alkaline AA batteries sold
separately
10
Universal Remote and
Universal Remote
Manual
IR detector
Resistor – 220 Ω
Jumper wires – bag of
3 2 1