AMICUS18-COMPANION-SHIELD AMICUS, AMICUS18-COMPANION-SHIELD Datasheet - Page 8

• Manufacturer Part Number: AMICUS18-COMPANION-SHIELD
• Description: Amicus18 Companion Shield
• Manufacturer: AMICUS

Specifications of AMICUS18-COMPANION-SHIELD

• Silicon Manufacturer: Microchip
• Core Architecture: PIC
• Core Sub-architecture: PIC18
• Features: USB Interface, In Circuit Serial Programming Interface
• Kit Contents: Board
• Silicon Family Name: PIC
• Silicon Core Number: PIC18F25K20
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: PIC18F25K20 Microcontroller

First Program
We’ll jump straight in at this point and produce our very first program that does something, but not us-
ing the companion shield just yet.
Open the AmicusIDE and type in the following code. Note that it is
mented texts. i.e.
' Flash an LED connected to RB0
' Make sure the Amicus18 board’s jumper Q3 is set to the GND position
Move jumper
connected to RB1, and the Anode connected to RB0. The Cathode is identified by being the shorter of
the two wires, and also the body of the LED has a flattened side.
Connect the USB cable to the Amicus18 board, and make sure its red Power LED is illuminated. Press
the
bootloader will open to place the compiled code into the Amicus18’s microcontroller. The LED will then
start flashing.
The above layout works as expected, however, some rules have been broken in so much as the LED
does not have a current limiting resistor in series with it. This means that the LED is seeing the full 3.3
Volts instead of it’s working voltage of approx 2 Volts, and is pulling too much current from the micro-
controller’s IO pin. We can alleviate this situation by using the Companion Shield with a solderless
breadboard.
The correct method for connecting an LED is shown overleaf.
Crownhill AssociatesLimited 2009 - All Rights Reserved
While 1 = 1
Wend
Compile and Program
High RB0
DelayMs 500
Low RB0
DelayMs 500
Q3
to the
blue texts
Gnd
' Create an infinite loop
' Bring the LED pin high (illuminate the LED)
' Wait 500ms (half a second)
' Pull the LED pin low (Extinguish the LED)
' Wait 500ms (half a second)
' Close the loop
button on the toolbar, or press F10. The code will then be compiled, and the
Amicus18 Companion Shield
Version 1.0
:
position, and place an LED into PortB pins RB0 and RB1, with the Cathode
7
not
required to type in the com-
06-10-2009