1818281+1818282 Microchip Technology, 1818281+1818282 Datasheet - Page 27

• Manufacturer Part Number: 1818281+1818282
• Description: EDF / AMICUS18 + SHIELD, BUNDLE
• Manufacturer: Microchip Technology
• Type: Development Boardr

Specifications of 1818281+1818282

• Kit Contents: Board
• Svhc: No SVHC (15-Dec-2010)
• Kit Features: Nine 10-bit ADC Inputs, Two 10-bit PWM Outputs, Two Comparators
• Mcu Supported Families: PIC18F25K20
• Silicon Manufacturer: Microchip
• Core Architecture: PIC
• Core Sub-architecture: PIC18
• Silicon Core Number: PIC18F
• Silicon Family Name: PIC18FxxKxx

Notice how the state of the pin is 1 when the button is pressed. This is because the weak pull-up resis-
tor (22K
Volts when it’s operated. This is the exact opposite of using a pull-up resistor.
Now that we know that the pin’s state is 1 (high) when the button is operated, decisions can be made
upon it.
The program below will flash the LED 10 times when the button is pressed:
' Demonstrate a switch input using a pull-down resistor
' Flash an LED based upon a button press
'
'------------------------------------
' Subroutine to flash the LED
FlashLED:
'------------------------------------
' Main program starts here
Main:
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Dim Flash As Byte
Symbol Switch = RB4
Symbol LED = RB0
GoTo Main
For Flash = 0 To 9
Next
Return
Input Switch
While 1 = 1
Wend
Ω
) holds the pin to ground when it’s not being operated, and the button pulls the pin to 3.3
High LED
DelayMS 100
Low LED
DelayMS 100
If Switch = 1 Then
EndIf
GoSub FlashLED
Amicus18 Companion Shield
Version 1.0
' Holds the amount of flashes
' Button is connected to RB4 (PortB.4)
' LED attached to RB0
' Jump over the subroutine
' Create a loop of 10 iterations
' Illuminate the LED
' Wait 100 milliseconds
' Extinguish the LED
' Wait 100 milliseconds
' Close the loop
' Exit the subroutine
' Make the button pin an input
' Create an infinite loop
' Is the button pressed ?
' Yes. So flash the LED
' Do it forever
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06-10-2009