28123 Parallax Inc, 28123 Datasheet - Page 86

• Manufacturer Part Number: 28123
• Description: TEXT WHAT'S A MICROCONTROLLER
• Manufacturer: Parallax Inc
• Type: Programmingr

Specifications of 28123

• Style: Book
• Title: What's a Microcontroller?
• Contents: Whats a Microcontroller? Text
• Product: Microcontroller Accessories
• Core Processor: PIC16C57c
• Flash: 128 Bytes
• Operating Supply Voltage: 9 V
• Board Size: 31 mm x 16 mm
• Lead Free Status / RoHS Status: Not applicable / Not applicable

Programming the BASIC Stamp to Monitor the Pushbutton
The BASIC Stamp stores the one or zero it senses at I/O pin P3 in a memory location
called
Example Program: ReadPushbuttonState.bs2
This program makes the BASIC Stamp check the pushbutton every ¼ second and send
the value of
the program is running. When the pushbutton is pressed, the Debug Terminal displays
IN3
Vdd
Vdd
. Here is an example program that shows how this works:
Binary and Circuits: The base-2 number system uses only the digits 1 and 0 to make
numbers, and these binary values can be transmitted from one device to another. The
BASIC Stamp interprets Vdd (5 V) as binary-1 and Vss (0 V) as binary-0. Likewise, when
the BASIC Stamp sets an I/O pin to Vdd using
I/O pin to Vss using
binary numbers used by many computer chips and other devices.
IN3
10
10
to the Debug Terminal. Figure 3-8 shows the Debug Terminal while
kΩ
kΩ
Vss
Vss
LOW
220
220
Ω
Ω
, it sends a binary-0. This is a very common way of communicating
SOUT
SOUT
VSS
VSS
ATN
ATN
SIN
SIN
P0
P1
P2
P3
P4
P5
P6
P7
P0
P1
P2
P3
P4
P5
P6
P7
10
11
12
10
11
12
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
BS2
BS2
BS2-IC
BS2-IC
1
0
1
0
19
18
17
16
15
14
13
19
18
17
16
15
14
13
24
23
22
21
20
24
23
22
21
20
VIN
VSS
RES
VDD (+5V)
P15
P14
P13
P12
P11
P10
P9
P8
VIN
VSS
RES
VDD (+5V)
P15
P14
P13
P12
P11
P10
P9
P8
HIGH
, it sends a binary-1. When it sets an
Figure 3-7
BASIC Stamp Reading
a Pushbutton
When the pushbutton is
pressed, the BASIC
Stamp reads a 1
(above). When the
pushbutton is not
pressed, the BASIC
Stamp reads a 0
(below).