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Infrared Line Follower Kit (#28034)
The Infrared Line Follower Kit from Parallax provides eight infrared emitter and receiver pairs for high-
precision line-following applications. Mounting hardware for both the Boe-Bot
®
and Stingray
™
robots are
also included for easy startup.
All IR frequency generation is done onboard using an ICM7555 chip, requiring no external signaling. This
allows for simple interfacing to the Infrared Line Follower, since the user only needs to read the state of
each IR receiver to detect white or black surfaces. An “Enable” pin is also included which when pulled low
puts the Infrared Line Follower into low-power mode.
Features
Compatible with both the Boe-Bot and Stingray robots from Parallax
Onboard 3 V regulator for easy use with Propeller-powered robots
Easily adjust 38–43 kHz IR frequency using an onboard potentiometer (See Calibration, page 8)
Onboard LEDs for instant line detection communication
High immunity to ambient lighting conditions
Mounting hardware included
No external signaling required
Key Specifications
Power Requirements: 3.3– 5.5 VDC;
maximum 35 mA working, 30 µA
when disabled
Communication: Single bit high/low
output for each IR emitter/receiver
pair
Operating temp: 32 to 140 °F
(0 to 50 °C)
Dimensions: 3.03 x 1.33 in
(7.7 x 3.4 cm)
Application Ideas
Line following
Maze navigation
Robotic contests
Detect line stripe width
Edge detection
Copyright © Parallax Inc.
Infrared Line Follower Kit (#28034)
v1.0 1/18/2011 Page 1 of 9
Bill of Materials
Part #
-
-
-
-
-
710-00007
700-00028
700-00060
713-00007
700-00003
Quantity
1
2
1
2
1
2
2
2
2
2
Description
Infrared Line Follower PCB
10” 4-pin female/female cables
10” 3-pin female/female cable
4-pin male/male headers
3-pin male/male header
7/8" 4-40 pan-head screws
1/4" 4-40 pan-head screws
1" round standoffs
1/2" round spacers
4-40 x 3/8" nuts
Additional Items Required
#2 Philips-head screwdriver
Black 3/4" electrical tape
White poster board
Resources and Downloads
Check for the latest version of this document, free software, and example programs from the Infrared
Line Follower Kit product page. Go to www.parallax.com and search 28034.
Theory of Operation
Upon connecting power, the onboard ICM7555 chip begins sending a 38–43 kHz signal through all 8 IR
LEDs. If the IR LED is over a white surface, light is reflected to the IR receiver, and its output is low.
When the IR LED is over a black surface, no light is reflected to the IR receiver, and its output is high.
The voltage regulator included on the PCB limits the power to the Infrared Line Follower’s circuitry to 3 V.
This means that a 5 V supply can safely be used with microcontrollers operating at 3.3 V.
Red LEDs located on the top of the board are wired to the output of each IR receiver, and the anode of
each LED is connected to power. When the IR LED is over a white surface, the low signal completes the
LED circuit and turns the LED on. Conversely, when the IR LED is over a black surface, the LED receives
dual high signals and the LED is off. This allows for easy visual feedback of the Infrared Line Follower’s
output states.
An onboard potentiometer also allows for the easy adjustment of the infrared frequency between 38 and
43 kHz. This allows the sensor to detect different colored lines, and also allows for the easy adjustment
of the sensor to different lighting conditions or mounting positions. For more information on how to
calibrate the sensor, see the Calibration section on page 8.
To isolate each IR senor and prevent false triggering, headers are placed between each IR emitter and
receiver pair.
Copyright © Parallax Inc.
Infrared Line Follower Kit (#28034)
v1.0 1/18/2011 Page 2 of 9
Quick-Start Guide
Before using the Infrared Line Follower, it’s a good idea to test the sensor’s responsiveness in the area
intended for use. This section includes instructions for mounting and testing the Infrared Line Follower on
your Boe-Bot or Stingray robot, as well as for calibrating it in your lighting conditions. In order to use the
example code below, you will need a strip of black electrical tape on white paper.
Boe-Bot Assembly Instructions
To mount the Infrared Line Follower on your Boe-Bot robot, you will need the following materials:
(2) 7/8" 4-40 pan-head screws
(2) 1/4" 4-40 pan-head screws
(2) 1" round standoffs
(2) 1/2" round spacers
Step 1
Insert the 7/8" screws through the top of the Boe-
Bot chassis through the left and right slots at the
front.
Step 2
On the underside of the chassis, slip on the 1/2"
unthreaded spacer on each screw, followed by the
1" standoff. Don’t tighten the standoff completely
to allow for easier alignment of the Infrared Line
Follower’s mounting holes in the next step.
Copyright © Parallax Inc.
Infrared Line Follower Kit (#28034)
v1.0 1/18/2011 Page 3 of 9
Step 3
Align the threaded standoffs with the mounting
holes on the Infrared Line Follower and use the
1/4" screws to secure the sensor to the screws.
The Infrared Line Follower should be facing
downward, with the headers pointing toward the
tail wheel.
Stingray Assembly Instructions
To mount the Infrared Line Follower on your Stingray, you will need the following materials:
(2) 7/8" 4-40 pan-head screws
(2) 1/2" round spacers
(2) 4-40 x 3/8" nuts
Step 1
Remove the front Stingray plate and insert the 7/8"
screws through the top of the chassis through the
front slot.
Copyright © Parallax Inc.
Infrared Line Follower Kit (#28034)
v1.0 1/18/2011 Page 4 of 9
Step 2
On the underside of the chassis, slip on the 1/2"
unthreaded spacer on each screw.
Step 3
Align the screws with the mounting holes on the
Infrared Line Follower and use the nuts to secure
the sensor to the screws. The Infrared Line
Follower should be facing downward, with the
headers pointing toward the tail wheel.
Pin Definitions
Pin
1
2
3
4
5
6
7
8
9
10
11
Name
GND
Vdd
EN
OUT0
OUT1
OUT2
OUT3
OUT4
OUT5
OUT6
OUT7
Type
G
P
I
O
O
O
O
O
O
O
O
Function
Ground -> 0V
Supply Voltage
Enable pin, pull low for low-power mode
Output state of IR receiver 0
Output state of IR receiver 1
Output state of IR receiver 2
Output state of IR receiver 3
Output state of IR receiver 4
Output state of IR receiver 5
Output state of IR receiver 6
Output state of IR receiver 7
Pin Type: P = Power, G = Ground, I = Input, O = Output
Copyright © Parallax Inc.
Infrared Line Follower Kit (#28034)
v1.0 1/18/2011 Page 5 of 9
嵌入式系统
