Sau gan 1 thang tim hieu, em viet code nhung rat tiec lai ko chay . Em sap phai nop BTL roi, mong moi nguoi giup do... Thanks!
File rht02.txt la code cua em da viet.
con day la link down chuong trinh bien dich MikroC PRO for PIC:
http://www.mikroe.com/eng/product_downloads/download/
vxl em dung la PIC18F4550 ,thach anh ngoai 8Mhz