910-90005 Parallax Inc, 910-90005 Datasheet - Page 13

• Manufacturer Part Number: 910-90005
• Description: KIT BASIC STAMP-PORTABLE DEVICE
• Manufacturer: Parallax Inc
• Series: BASIC Stamp®r
• Type: Education Kitr

Specifications of 910-90005

• Contents: Board, cable, components, manual and temperature sensor
• For Use With/related Products: BASIC Stamp® 2 and Board of Education
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Example Program
Introduction
As we mention in the section on electronics fundamentals, Light Emitting Diodes (LED) are the most widely used
indicators in the electronics world. They come in a tremendous variety of colors, shapes and sizes. Their low
current requirements make them perfect for digital control. Through a simple series of experiments, you'll learn
how to have control over an LED and also the ins-and-outs of working with BASIC Stamp microcontroller outputs.
With this knowledge you'll be able to extend your digital control of the outside world to relays, motors – to any
device that requires on or off control.
For our first experiment we'll need just an LED and a 220-ohm (Red-Red-Brown) resistor. Connect the 220-ohm
resistor between pin P15 and the breadboard. Connect the LED between the same section of the breadboard
and Vss. If you look closely at the LED you'll notice that one side of the body has a flat spot. The leg near the flat
spot is the cathode side of the LED and connects to Vss (Figure 5.1).
How it Works
You know by now that we must provide a forward-biased current through the LED in order for it to illuminate. For
this to happen, the anode (arrow) must be more positive in respect to the cathode (bar).
The BASIC Stamp output pins can have one of two states: off (0 volts) or on (5 volts). So if we cause the P15
output pin to be on, we will provide five volts to the anode of the LED through the resistors. In our circuit the LED
will be forward biased and illuminate.
Parallax, Inc. • BASIC Stamp HomeWork Board ver 1.1
Page 13