Problem with bootloader - chksum error

TSEYFARTH · Joined: 01 Jul 2006 Posts: 1042

Hello all,

I am using an Atmega644PA-20 with a 20MHz external crystal. The bootloader is set for 9600 baud, and has the following set:
Config Print0 = portd.2 , Mode = Set
Config portd.2 = Output 'set the direction yourself

This same code appeared to work with a 16Mhz crystal (and the bootloader code was also set to 16MHz). However now, this new bootloader *only works when an AVRISP MKII is also plugged in. Without the AVRISP, an error occurs quickly in the process. Previously, and this may be coincidental, the bootloader worked perfectly when the bootloader, and the chip used a 16MHz crystal.

I have seen this before but never could isolate it or understand the problem.

Any ideas would be appreciated!
Thank you,
Tim

(BASCOM-AVR version : 2.0.7.8 )