Ing. electronico

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 toprototype 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 orother 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 (makeyour 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 vieUSB 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 theboard 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 powersupply 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 – 15VDC 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...