Olimex PIC-USB-4550 User guide

PIC-USB-4550 development board

Users Manual

Rev.A, June 2007

Copyright(c) 2007, OLIMEX Ltd, All rights reserved

INTRODUCTION:

PIC-USB-4550 board is development board, which allow you to
prototype and develop USB applications with PIC18F4550
microcontrollers.

What you can do with PIC-USB-4550? Let’s see what we have:
PIC-USB-4550 have USB connector to connect and interface with PC or

other USB host. Microchip provide free firmware for USB HID (human
interface device) device which you can use to make custom mouse,
joystick, CDC (communication class device), Audio class device (make
your own microphone, speaker etc USB devices), Mass storage device
(add your own USB disks), USB to RS232 etc etc. Using the Microchip
bootloader you can program your code and change your firmware vie
USB without the need for programmer!

The on-board ICSP connector allow you to program the PIC on the
board without pulling it of the socket, by ICSP programmer like PIC­MCP, PIC-MCP-USB, PIC-PG1, PIC-PG2, PIC-PG3, PIC-PG4 or to
program and debug it with PIC-ICD2, PIC-ICD2-POCKET or PIC-ICD2­TINY.

PIC-USB-4550 can be powered from the USB or from external source.
This is jumper selectable. When the board is powered from the USB
your power budget is 5V/100mA i.e. your circuit should not exceed
this power. If your circuit need more power you can connect external
power supply. The external power supply circuit have diode bridge
after the power supply jack which allow you to power this board with
both AC and DC power supply adapters. The input voltage could be
anything within the range +7.5 – 15V DC or 6-12V AC.

The oscillator circuit is made with 20 Mhz crystal oscillator, so you
can run your PIC at maximum performance.

The RESET circuit is made with simple RC circuit and RESET push
button.

PIC-USB-4550 have user button for user input connected to PIC
microcontroller’s RC4 port. When RC4 port is initialized as INPUT you
will read “0” when the button is pressed and “1” when it is depressed.
This button also is used to enter BOOTLOADER programming mode.

Status LED is connected via jumper to PIC microcontroller’s RD3 port.
When your RD3 port is initialized as OUTPUT and set to “0” LED will
go ON, when RD3 port is set to “1” LED will go OFF.