serial or pwm for motor controler?

which one would be easyer i have ordered the Arduino Duemilanove a few days ago and it is being shipped so i don't have it yet to try anything and since this is my first micro controler project im still a noob (contructive critisimn please :) )and i have found 2 cheap motor controlers one is serial and one is PWM i know about the motor shield but i don't have a good solder gun and i can't find it anywere assembled. so my question is what one will be the easyest to program and run 2 motors at the same time. it looks to me that the serial one would be the easyest but in the code samples for teh arduino i cna only find were it sends charaters to the serial and not the actual bytes. also if anyone could point me to some good turtorials that would be nice. ty

I have never used serial motor drivers so I don't know much about them, but i have used pwm controlled motor drivers.

For pwm controlled drivers like http://www.sparkfun.com/commerce/product_info.php?products_id=8905, you control the speed of the motor by pulsing the PWM pin. The arduino has pins that automatically pulse when they recieve an analogWrite(pin#, value(0-255));

Here is an example sketch from the playground. http://akashxav.com/2009/04/18/arduino-l293d-dc-motor/

int pwmPin = 9;  //Motor's PWM pin
int dPin_1 = 6;// Digital Pin to turn the motor on/off
int dPin_2 = 7;
int ledPin = 13; //LED pin

void setup()
{
pinMode(dPin_1, OUTPUT);
pinMode(dPin_2, OUTPUT);
pinMode(ledPin, OUTPUT);
}

void loop()
{
digitalWrite(ledPin, HIGH); // turn on LED
digitalWrite(dPin_1, HIGH); //turn on the motor
digitalWrite(dPin_2, LOW);

//Apply PWM to the motor
for(int i=0; i<=255; i++)
{
analogWrite(pwmPin, i);
delay(100);
}

delay(1000); //delay for a second

//switch directions
digitalWrite(dPin_1, LOW);
digitalWrite(dPin_2, HIGH);

for(int i=255; i>=0; i--)
{
analogWrite(pwmPin, i);
delay(100);
}

digitalWrite(ledPin, LOW); // turn off LED
digitalWrite(dPin_1, LOW); //turn off motor

delay(2000); //delay for 2 seconds.
}

I would think the advantage of using the serial motor drivers is that you would only need 2 digital pins per motor to control speed and direction. Where you would need a least 3pins using pwm. As long as you have enough pins, I would think the pwm route is easier and probably cheaper.

i cna only find were it sends charaters to the serial and not the actual bytes

Characters are bytes and bytes are characters, they are just different ways of representing eight binary bits. So if you want to send the bit pattern 01110101 you would do:- s = 0x75; serial.print(s, BYTE);

I have never seen a serial motor, are you mistaken about this? :-?

You might get an expensive motor control that has a serial interface but normally where serial is involved there is a micro computer at each end of the link. I know there are some exceptions but normally this is true.

ok thanks for the info i can't wait till my baord gets here(tracking it and its in transit to destination :D ) and thanks for that info and btw it was a serial motor DRIVER not a serial motor but thanks for the info as now i have a better idea as to what to expect when i get my parts. if i run into any problems assembling it you'll probably see more of my post lol