DM164120-1 Microchip Technology, DM164120-1 Datasheet - Page 28

• Manufacturer Part Number: DM164120-1
• Description: BOARD DEMO PICKIT 2 LP COUNT
• Manufacturer: Microchip Technology
• Type: MCUr

Specifications of DM164120-1

• Contents: 3 Boards (1 Populated, 2 Bare)
• Processor To Be Evaluated: PIC16F690
• Silicon Manufacturer: Microchip
• Core Architecture: PIC
• Core Sub-architecture: PIC16
• Silicon Core Number: PIC16F
• Silicon Family Name: PIC16F6xxx
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: 28-pin PIC16C, 16F, 18C, 18F
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Low Pin Count Demo Board User’s Guide
DS51556A-page 24
One of the simplest ways to switch debounce is to sample the switch until the signal is
stable or continue to sample the signal until no more bounces are detected. How long
to continue sampling requires some investigation. However, 5 mS is usually plenty
long, while still reacting fast enough that the user won’t notice it.
Lesson 6 shows how to sample the line at a 1 mS rate waiting for a number of
sequential state changes, which is a simple matter of counting to 5, then resetting the
counter every time it’s still in the original unchanged state.
The Switch on the LPC Demo Board doesn’t bounce much, but it is good practice to
debounce all switches in the system.
FIGURE 3-6:
Increment Counter
Reset Counter
Change State
Is Counter = 5?
SIMPLE SWITCH DEBOUNCE PROGRAM FLOW
Yes
Yes
changed states?
Delay 1 mS
Switch has
No
Reset Counter
No
© 2005 Microchip Technology Inc.