Re: [avr-chat] Boot loader weirdness

[Alan Kilian]

On Sat, 2005-06-18 at 21:41 -0700, Larry Barello wrote:
> I have a boot loader I derived from Jason Kyle's stk500boot.c.  It works
> great.  However in one of my platforms it behaves erratically. 

    OK Larry, I know you are very experienced from your posts over the
    last few years, so please take this as a constructive suggestion.

    Since it works in one circuit, and does not in another....

    Do you have power and ground hooked up?

    Really. I've had problems in the past with other microcontrollers,
    and eventually I found I hadn't hooked up power, and the thing was
    being powered through the clamp diodes on the asynch-serial port.

    They worked almost perfectly, but just once in a while during 
    reprogramming, I'd get a bad byte written in flash since it 
    couldn't draw as much power as it wanted when writing to FLASH. It 
    was a pain to diagnose since it looked like a software failure.

    Maybe hook an LED to an output bit and see if the thing can source
    and sink current.

    I know it's obvious, and that it's just shy of 100% probable that
    you have everything hooked up right, but it's a thought.

                                -Alan

-- 
- Alan Kilian <kilian(at)bobodyne.com>