Datasheet

Chapter 3: EEPROM Tricks and Program Tips · Page 95
√ Modify TestIrFrontObjecDetectors.bs2 so that it has 3 or 4 useful versions of the
IrFreq CON directive.
ACTIVITY #2: A CLOSER LOOK AT THE QTI LINE SENSORS
The SumoBot shown in Figure 3-7 has its QTI line sensors mounted under left and right
sides of the plow. The QTIs are designed to detect the white tawara line, which is the
border of the competition ring. This activity reviews the testing procedure for the QTI
line sensors and takes a closer look at how they work.
Figure 3-7 QTI Line Sensor's on the SumoBot
Testing the QTI Line Sensors
Figure 3-8 shows schematics of your SumoBot's two front QTI line sensors. Like the IR
object detectors, the QTI's are connected to headers on your SumoBot. When you plug
the cable into the QTI, the white wire should line up with the W on the QTI. Likewise,
the red wire should line up with the R, and black with B. When plugging the other end of
the cable into the header on the SumoBot board, make sure to line up the black wire with
the pin labeled B. On the SumoBot PCB, the X5 header connects the pin labeled 10 to
BASIC Stamp I/O pin P10. The PCB also connects the pin labeled 9 to I/O pin P9, and
the pin labeled B to Vss. Header X4 makes similar connections, but with different I/O
pin connections.
QTI Line Sensor
(Front Left)
QTI Line Sensor
(Front Right)