Configuring Esteps

I'm configuring the esteps. I extruded 100mm thru ponterface but in actuality got 102 does this mean that my esteps line should read:

#define E_STEPS_PER_MM 1.02((3200 * 39.0)/(11.0 * 6.75 * 3.142))?

Also when I attempt to upload to the Melzi I get the error: avrdude: stk500_getsync(): can't communicate with device: resp-0x89. (I am using a Mac if that matters) what am I doing wrong?

Now when I try to connect to the computer in Ponterface I get an error that says: "Printer is online. Attempted to write invalid text to console, which could be due to an invalid buad rate." And now I can no longer control the printer with ponterface. (It was working before I tries to update the firmware. (Uhh....so close to printing, yet so far . . .)

Edited 4 time(s). Last edit at 01/22/2014 10:22PM by academicdave.

No it should be:

#define E_STEPS_PER_MM ((3200 * 39.0)/(11.0 * 6.75 * 3.142) * 100.0/102.0)

I.e. you want less steps as it is over extruding slightly.

When uploading are you sure you selected the correct serial port, set board to Melzi with ATmega1284P 16MHz and have the reset jumper fitted?

If you haven't succeeded in uploading the firmware I can't see how the baud rate has changed unless you managed to erase it and you are just talking to the bootstrap with Pronterface. I have never done that so I don't know what it would look like. I think the bootstrap talks at 38kB.

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[www.hydraraptor.blogspot.com]

Thanks re: esteps. That makes sense.

re:firmware. Don't know what was happening. But I started the whole process over from the beginning and it worked. It seems thought that if I am connected with Ponterface I can't update the firmware, but it works as long as I disconnect first.

Yes that is case on Windows as well.

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[www.hydraraptor.blogspot.com]

Thanks. Managed to get a fairly good first print. Some problems with it not sticking to the bed, but I'll start another thread for advice on this. But I am really pleased with how well the first one came out.