Radio Shack Mobile Robot - Manual (Page 43)

Expansion Port Circuit Examples
continued
40
Digital Inputs -
Basic Stamp input signals can be used to read
TTL level signals such as switches or
sensors. The input signal should not exceed
+5 volts DC or go below 0 volts. Each input
pin has a pull-up resistor to +5 volts.
Switch Input Example:
This example shows how to interface a
mechanical switch to one of the digital
Sensor Input Example:
This example shows how to interface a
sensor that has an open collector (OC) output
to a digital input.
Digital Circuit Input Example:
This example shows how to attach logic gates
to the digital input signals.
Digital/Power Output -
The digital signals can be used to control external circuitry. Large loads can be driven with an external
power transistor such as a MOSFET. A clamping diode should be included to protect the transistor
when switching inductive loads such as relays.
Power Output Example
Digital Output Example
More expansion information
Our space is limited here so make sure to visit our web site for the latest expansion application notes
complete with program examples. www.robotics.com/arobot/projects.html
Also visit the Parallax web site which has an entire section dedicated to application notes for the Basic
Stamp II. www.parallaxinc.com