AVR-Chat

Okay I remember you mentioning this before. 

Now for some details.

I assume I will need to connect both boards to the same power 
source. ie so they will have common ground. 

I can figure out how to get the good board to generate the on off 
pulse (It is just a matter of doing the math but I do not have the 
data sheet with me now.) Does it have to be exactly 1MHZ?

Now for hooking up the boards, I as long as the both run to the same 
ground, I just run a wire from my output pin on the good board to 
the "right hand" pad. Right? 

By right hand pad I assume you mean if you hold the board so the 
MAVRIC II label is at the top and correct side up. In other words on 
the same side as the voltage regulator. 

By pad I am guessing this is a surface mount piece. which means 
temporarily attaching a wire is going to be real fun (NOT) 


Looks like I have a fun night ahead.

Is this all correct.

 

--- In AVR-Chat@yahoogroups.com, Brian Dean <bsd@b...> wrote:
> On Thu, May 19, 2005 at 11:14:16PM -0400, wbounce wrote:
> 
> > This all started when I tried to program the problem board with 
an
> > updated program. It did its usually reading ### 100% and device
> > signature messages and started on the writing #### part when 
wheels
> > on my robot started turning. It finished writing and reading 
again
> > and then it failed verification.
> 
> I wonder if there could have perhaps been a power supply brown-out
> during programming which corrupted the fuse bits?
> 
> One of the most common fuse bit problems is setting the fuse bits 
to
> use an external clock as opposed to the external crystal or 
internal
> oscillator.  When set to use an external clock, then the chip won't
> run and will refuse to be programmed until an external clock is
> provided.
> 
> Try supplying around a 1 MHz TTL square wave into the XTAL1 input 
(pin
> 24).  You can easily access this pin by the right hand pad of the
> external crystal.  You can supply this with most any function
> generator (just be sure you limit the voltage to 5V), or even a 
second
> AVR board simply programmed to toggle one of its I/O pins.
> 
> With the signal applied, retry entering programming mode.  If you 
get
> into programming mode, then you can reset the fuses back to their
> defaults and you should run normally after that.  The default 
fuses on
> your MAVRIC-II board are: efuse=0xff, hfuse=0x89, lfuse=0x3f.
> 
> -Brian
> -- 
> Brian Dean
> BDMICRO - ATmega128 Based MAVRIC Controllers
> http://www.bdmicro.com/