Replacing A4988 Drivers with DRV8825 on Arduino Mega 2560 + Ramps

[Mjolinor]

Why do you think there is something wrong with it?

No amount of changing hardware is going to alter USB specifications. They are written by a standards committee and they are written in such a way that they are not suitable for real time communications.

[PyramidDave]

Using Octoprint from Raspberry Pi or connected directly to my computer using USB will give me a communication error after a short time & the printer stops. Printing directly from the SD card does not cause my printer to stop. Unless there is a problem on the USB connection on my computer & raspberry the problem looks like it points to somewhere in the USB circuitry of the arduino. Is that logic not correct? I have also tried 2 different USB ports on my computer with the same problem. Is there some Ethernet shield that I could attach to the arduino mega instead of using the USB connection?

[Mjolinor]

Using Octoprint from Raspberry Pi or connected directly to my computer using USB will give me a communication error after a short time & the printer stops. Printing directly from the SD card does not cause my printer to stop. Unless there is a problem on the USB connection on my computer & raspberry the problem looks like it points to somewhere in the USB circuitry of the arduino. Is that logic not correct? I have also tried 2 different USB ports on my computer with the same problem. Is there some Ethernet shield that I could attach to the arduino mega instead of using the USB connection?

No that is not correct. Read what I have written. USB specification does not support real time protocol.

USB SPECIFICATION DOES NOT SUPPORT REAL TIME PROTOCOL.

Any clearer?

Three times I said it now, this is the last time.

[PyramidDave]

What I do not understand is how I have been using it successfully for 1.5 years without this problem & all of a sudden I have a problem. If the fact that USB does not support real time protocol played into this problem, wouldn't I have had a problem a long time ago? I have 2 to 3 thousand hours of printing on this printer.

What electronics are you using on your printer and how do you connect to it?

[kd7eir]

Why do you think there is something wrong with it?

No amount of changing hardware is going to alter USB specifications. They are written by a standards committee and they are written in such a way that they are not suitable for real time communications.

I have hundreds of hours of printing using a Raspberry Pi and OctoPrint and have never had a single communications error.

[Mjolinor]

I have hundreds of hours of printing using a Raspberry Pi and OctoPrint and have never had a single communications error.

And? Do you think this somehow changes the written specifications of the standard?

Lots of people have hundreds of hours with no problem but then again, lots of people jump out of windows and don't break legs.

[kd7eir]

And? Do you think this somehow changes the written specifications of the standard?

Lots of people have hundreds of hours with no problem but then again, lots of people jump out of windows and don't break legs.

It PROVES that it works in spite of "experts" like you trashing it.

You have contributed NOTHING to this discussion. People come here for help, not pedantic lecturing. Eat a Snickers, maybe you'll feel better.