Hello,

I recently bought a pic/xbee robotic controller board online from www.droids.it . I must say the price was alright and the pcb quality is excellent BUT I just cant figure this one out. It has an 18f2520 with a 10Mhz smt crystal, according to the docs it is actually running at 40Mhz, I assume that has been accomplished by the provided pre-programmed software. So using my awesome U2 programmer, I dumped a simple program to the pic to have it send "hello world" at 9600 baud and receive it on a serial LCD. The exact same setup was used with a 16f873 at 4Mhz and worked great. With the 18f at 10Mhz I only get garbage on the output. So, I then removed the 10Mhz xtal, installed a 4Mhz xtal and it worked. Obviously the pic timing is off when using the 10Mhz xtal, but can I work around this issue in software or is my 4Mhz Xtal the best solution. Heres the program:

INCLUDE "MODEDEFS.BAS"

start:

low porta.4 ' Status LED
pause 500
high porta.4

serout2 portc.6,84,["Hello World...."]

pause 500
goto start