28125 Parallax Inc, 28125 Datasheet - Page 185
28125
Manufacturer Part Number
28125
Description
TEXT ROBOTICS
Manufacturer
Parallax Inc
Datasheet
1.28125.pdf
(360 pages)
Specifications of 28125
Title
Robotics with the Boe-Bot
Product
Microcontroller Accessories
Lead Free Status / RoHS Status
Not applicable / Not applicable
- Current page: 185 of 360
- Download datasheet (5Mb)
Testing the Whiskers
Take a second look at the whiskers schematic (Figure 5-7). Each whisker is both the
mechanical extension and the ground electrical connection of a normally open, single-
pole, single-throw switch. The reason the whiskers are connected to ground (Vss) is
because the plated holes at the outer edge of the board are all connected to Vss. This is
true for both the Board of Education and the BASIC Stamp HomeWork Board. The
metal standoffs and screw provide the electrical connection to each whisker.
The BASIC Stamp can be programmed to detect when a whisker is pressed. I/O pins
connected to each switch circuit monitor the voltage at the 10 kΩ pull-up resistor.
Figure 5-8 illustrates how this works. When a given whisker is not pressed, the voltage at
the I/O pin connected to that whisker is 5 V. When a whisker is pressed, the I/O line is
shorted to ground (Vss), so the I/O line sees 0 V.
All I/O pins default to input every time a PBASIC program starts. This means that the
I/O pins connected to the whiskers will function as inputs automatically. As an input, an
I/O pin connected to a whisker circuit will cause its input register to store a 1 if the
voltage is 5 V (whisker not pressed) or a 0 if the voltage is 0 V (whisker pressed). The
Debug Terminal can be used to display these values.
P7
P5
220
220
Ω
Ω
Vdd
Vss
10
Right
Whisker
kΩ
Vdd
Vss
10
Left
Whisker
kΩ
Figure 5-7
Whiskers
Schematic –
A Second
Look
Related parts for 28125
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Microcontroller Modules & Accessories DISCONTINUED BY PARALLAX
Manufacturer:
Parallax Inc
Part Number:
Description:
BOOK UNDERSTANDING SIGNALS
Manufacturer:
Parallax Inc
Datasheet:
Part Number:
Description:
COMPETITION RING FOR SUMOBOT
Manufacturer:
Parallax Inc
Datasheet:
Part Number:
Description:
TEXT INFRARED REMOTE FOR BOE-BOT
Manufacturer:
Parallax Inc
Datasheet:
Part Number:
Description:
BOARD EXPERIMENT+LCD NX-1000
Manufacturer:
Parallax Inc
Datasheet:
Part Number:
Description:
CONTROLLER 16SERVO MOTOR CONTROL
Manufacturer:
Parallax Inc
Datasheet:
Part Number:
Description:
BASIC STAMP LOGIC ANALYZER
Manufacturer:
Parallax Inc
Datasheet:
Part Number:
Description:
IC MCU 2K FLASH 50MHZ SO-18
Manufacturer:
Parallax Inc
Datasheet: