122-27400 Parallax Inc, 122-27400 Datasheet - Page 49

• Manufacturer Part Number: 122-27400
• Description: MANUAL FOR SUMOBOT
• Manufacturer: Parallax Inc

Specifications of 122-27400

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

TESTING THE IR PAIRS
The key to making each IR pair work is to send one millisecond of unfiltered 38.5 kHz
FREQOUT harmonic followed immediately by testing the signal sent by the IR detector
and saving its output value. The IR detector’s normal output state when it sees no IR
signal is high (logic 1). When the IR detector sees the 38.5 kHz harmonic sent by the IR
LED, its output will drop from high to low (logic 0). Of course, if the IR does not reflect
off an object, the IR detector’s output simply stays high. Program 4.1 shows an example
of this method of reading the detectors
' SumoBot_4.1_IR_Sensor_Test.BS2
' {$STAMP BS2}
' {$PBASIC 2.5}
' -----[ I/O Definitions ]-------------------------------------------------
LfIrOut
LfIrIn
RtIrOut
RtIrIn
Figure 4.4: SumoBot IR Object Detection Components Installed
PIN
PIN
PIN
PIN
4
11
15
14
Chapter 4: Infrared Object Detection · Page 39
' left IR LED output
' left IR sensor input
' right IR LED output
' right IR sensor input