single arduino reprap

Dear folks,

I'm building a repstrap using an arduino 1280 and a uln2003 stepper-driver.
I know some of programming but USB communication is completly new to me.

now my problem is what does the reprap software send to the arduino and how can i read it with the arduino?

best regards,
ikke

The software sends gcode in ascii using a virtual com port. You should be able to read it with the serial class.

I wrote a little code to read it but I can't get any code from the reprap program.
I think somthing is going wrong in the settings of the reprap program.
the output is set to dev/com3
and the code I wrote is

char text;

void setup ()
{
Serial.begin (9600);
}

void loop()
{
if (Serial.available() > 0)
{
  text = Serial.read();
  Serial.print (text);
}
else
{
  Serial.println ("no input");
}
delay(500);
}

thx in advance

ikke Wrote:
-------------------------------------------------------
> Dear folks,
>
> I'm building a repstrap using an arduino 1280 and
> a uln2003 stepper-driver.

So are you planning to drive a unipolar motor using the ULN2003? with full stepping? - I would not recommend doing that for a RepRap/Repstrap - we tend to use Bipolar stepper drivers with 8x or 16x microstepping, you will get lots more usable torque and it actually makes the job much easier using a dedicated driver rather than a ULN array and doing it all in software.
You will not be able to drive a bipolar stepper with a ULN2003, and if you use a unipolar you will only get 500mA for each coil using a ULN.

---

[richrap.blogspot.com]

Currently I'm in the testing stage I use geared stepper motors with 2048 steps for one revolution.
and they're attached to a M6 threaded rod as axis drive.
so microstepping is not need yet and I'm also on a strict budget but dying to have a reprap.
as soon I get it up and running I'm going further to make it better. as it was born.

Remember that a Stepstick/Pololu is around $10, they do a great job.

Using a geared motor may be a problem in the long run as the print speed might suffer. 3D printing already takes a lot with "fast" repraps.

Threaded rods are also a way to get a slow axis drive, if you combine that with a geared stepper it should be ultra slow.

I know what it is to do things on a shoe string budget but I thought you might want to know about these shortcomings. Maybe you can find some used equipment if you ask around.

misan