DM163045 Microchip Technology, DM163045 Datasheet - Page 43

• Manufacturer Part Number: DM163045
• Description: PICDEM Lab Development Kit (with PICkit 3) General Purpose
• Manufacturer: Microchip Technology
• Series: PICDEM™r
• Type: MCUr

Specifications of DM163045

• Contents: Board, PIC kit 3
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: PIC Micro® MCU

© 2009 Microchip Technology Inc.
FIGURE 3-18:
The only change from the previous section is the inclusion of a push button connected
to RA2 with associated pull-up resistor.
3.4.4
3.4.4.1
To configure the peripherals used in this lab, the following registers are used:
1. PORTA Register: PORTA (Register 4-1 in Section 4 of the PIC16F690 Data
2. PORTA Tri-State Register: TRISA (Register 4-2 in Section 4 of the PIC16F690
3.4.4.2
This lab expands upon Lab 4 by adding a push button interface to change the direction
of the sequential shift in the PORTC register.
Mechanical switches play an important and extensive role in practically every
computer, microprocessor and microcontroller application. Mechanical switches are
inexpensive, simple and reliable. However, switches can be very noisy electrically. The
apparent noise is caused by the closing and opening action that seldom results in a
clean electrical transition. The connection makes and breaks several, perhaps even
hundreds, of times before the final switch state settles. The problem is known as switch
bounce. Some of the intermittent activity is due to the switch contacts actually bouncing
off each other. Also, switch contacts are not perfectly smooth. As the contacts move
against each other, the imperfections and impurities on the surfaces cause the
electrical connection to be interrupted. The result is switch bounce. The consequences
R8
470Ω
LED8
- 8-bit bidirectional port
- Configures corresponding bits in PORTA as either input or output
Sheet)
Data Sheet)
Lab 5: Adding a Push Button
NEW REGISTERS USED IN THIS LAB
OVERVIEW
LED7
R7
470Ω
General Purpose Input/Output Labs
LED6
R6
470Ω
PICDEM LAB SCHEMATIC FOR GPIO INPUT LABS
J8
LED5
R5
470Ω
10
1
2
3
4
5
6
7
8
9
RC6
RC7
RC5
RC4
RC3
U2
LED4
R4
470Ω
RC0
RA2
RC1
RC2
V
SS
20
19
18
17
16
15
14
13
12
11
R3
470Ω
LED3
J9
LED2
R2
470Ω
V
DD
R9
10KΩ
LED1
R1
470Ω
SW1
DS41369A-page 39
V
SS