[Fwd: Re: [avr-chat] New Programmer, Small Program, F_CPU for Atmega644]

[Robert L Cochran]

Ooops! I forgot that when I click reply, I'm sending to the sender and
not to the list as well. I apologize for this. See below for a followup
on my earlier posts.

Thanks!

Bob Cochran

------------------------------------------------------------

Joerg Wunsch wrote:
> Robert L Cochran <address@hidden> wrote:
>
>   
>> I was planning to use a lithium polymer battery that pumps out 12v
>> at 1300 mA. I connected that to a power supply board which will give
>> me 5v output and 1100 mA current.
>>     
>
> If that's a linear regulator, it will waste a lot of energy.
>
> If you've got a choice, a single LiIon cell delivers a voltage in the
> range of (3.0 ... 4.2) V (nominal voltage 3.7 V), this is a good power
> supply to drive an AVR directly from it, without any regulation.  You
> just have to mind the CPU frequency limit for the given voltage, which
> is 10 MHz max. for the ATmega644.
>
>   
Thanks a lot Joerg! I'll look into buying one. I'm learning a lot from
this and other posts. You have all been very good about educating me.
I'm grateful for the help. I recognize that I have a lot to learn about
basic electronics and the AVR. I want to learn.

To follow up with my earlier posts, I spent all day yesterday trying to
get avrdude to program the hex file you posted for me to my AtMega644. I
quickly forgot the hex file because I simply couldn't get avrdude to
"find" the device named usbtiny on my Fedora 7 (linux) box. (I built a
USBTinyISP programmer, produced as a kit by Limor Fried.) It doesn't
work when I m an ordinary user. I think that is significant because
running `lsusb` as a user will not show me any output, but running
`lsusb` as root will. My linux computer is an AMD Athlon 64 (x86_64)
machine and I'm running the Fedora 7 x86_64 code. By late last night, I
got frustrated with Fedora and went to my Microsoft Windows XP laptop
and tried the avrdude version that came with the 20071221 release of
WinAVR. After fixing some incorrectly placed ISP connectors, it was able
to find the usbtinyisp programmer and my ATMeg644 circuit. Avrdude was
able to do its "initialization" routine and exit normally. This greatly
cheered me, but by then it was pretty late at night so I stopped for the
day.

Tonight, I returned to trying to get the Fedora 7 flavor of avrdude to
"see" the usbtiny device, and I think I destroyed the programmer in the
process. I've posted most of the details separately to Limor Fried's
"LadyADA's Tea Party" forums:

http://www.ladyada.net/forums/viewtopic.php?t=5495

Well, I had gotten my feet wet with the code, and I suppose that is a
good thing. I have a feeling there are not too many people who use
avrdude on Fedora 7 and it hasn't had an extended amount of testing as a
result.

I want to thank everyone -- you, Marge, Bill, John, Eric, and Preston --
for your continued help. I'm going to stay with this until I learn how
to do things right.

Kindest Regards

Bob Cochran
Greenbelt, Maryland, USA