If you can convert your design to a surface mount, the 328 chip can be reduced to a (TQFP_32_ which is smaller than a dime.  Mostly whats going to determine the size is things like power and any peripheral component.  Do you need usb support?  Modern devices has an arduino compatible product called the RBBB that is roughly 2 times in each direction the size of the 328p dip chip.

He is trying to tell you to change


int ledPin =  13;  
int time_off = 1;
int time_on = 1;
 
to:

int ledPin =  13;  
unsigned long time_off = 1;
unsigned long = 1;

Memory wire typicaly needs a lot of wire I've messed with it a bit and I used the PWM to drive a Logic driven nFET  to control the wire.  The Arduino wont be able to drive the current without amplification

Sorry if I'b asking the obvious.  but I find that sometimes it is the best place to start.
Can you download any of the examples to the 164?

What is your serial port? an USB port or a real serial port? can you see the device under /dev/ ?

... if all else fails there is always the tradition "ohm it out" method.

The name of this sub-forum is "Frequently-Asked-Questions", Seems like if one doesn't want to see the same questions over and over again, that they would skip over reading this section.  Maybe we need a subforum named, "Questions Rarely Asked"

I have 2 boards, and discovered that. I can't upload to one board serially even if I swap 328 chips. Funny thing is that I can upload just fine using the usb adapter. The second board uploads just fine with the P4b serial adapter,  and both boards work well with the serial adapter and the arduino serial monitor.

At any rate what I thought was my OS computer system problem turns out to be my board problem .. think my next step is  to inspect with a magnifier and an ohm meter.  Wierd problem though.

I have a couple of Arduino RBBB inits and a 6 pin P4b RS232 to ttl adapter. My computer here has a real 9 pin serial connection..
All works fine using the bub usb to 6 pin at /dev/TTYUSB0 but I can't seem to get the port at /dev/ttyS0 to accept an upload.  It does do the reset. So I the port seems to be properly connected.  I did uninstall ttybrl.  Does anyone have any suggestions

Another old guy here.  Used teletypes to talk to the computers. paper tapes to load and boot them up. Have rebuilt more than my share of harddrives to know what a real head crash is.
SIngle sided 8 inch floppies were a codewriters salvastion.  Fortran was the language of the future and cobal was where the money was, but C was just a letter.

I tend to agree with rlwoodjr use the FET .. At 6 ohms and 12 volts you're trying to draw 2 amps. FETs tend to turn on at a lower resistance and therefore handle higher currents better.
Best of luck to you.

There is a PID control algorythem someone wrote for the arduino.
http://www.arduino.cc/playground/Code/PIDLibrary
There is the sompler expresso library also.
http://www.arduino.cc/playground/Main/BarebonesPIDForEspresso
I think this is what you are looking for.

They markings are the relive to to the cable.  The TX is the TX from the serial cable to be incomming on the board. the RX is the RX on the cable and will be th out going line from your AVR

While the Arduino made things a little easier and cheaper. 8 bit AVRs have been around for a while and development for a small emmbedded has been fairly and easy on those systems as well.  AVR Freaks has lots of hobbiest as well as professionals. AVRs have been about open source develpment.  Arduino just takes it all a step further.

Thanks for  all the input.  My desire to use a 1.0 version is simply to appeal to perception.  I have no concerns about the stability of the compiled  code. I have an STK500/stk600 and an MKii with Studio 4.  If I don't use the bootloader in the final product, I  don't have to explain it.    At any rate its not important whether 1.0 is released soon.  It just effects  how I go about releasing this thing.