My Melzi had one of the drivers go bad for the extruder, so I bought a new one on E-Bay. When I installed it and tried to home the axis's the motors would move a little bit and stop, one axis even went in the wrong direction( Yes the stepper was wired the same as before). I've searched and searched the net and found an article that says its a bootloader issue (fuses set wrong), buts its applies to GeeTech boards which mine isn't ( [www.geeetech.com]), and the programmers being used are ones I don't have all I have is an UNO.
I'm just not sure what to do at this point, flash bootloader or firmware?
If I flash firmware the settings are confusing the config file has all kinds of things in it that need to be selected, or uncommented, like is it a Melzi or a Sanguino. From what I saw on the net they are one and the same. Melzi is based on Sanguino.
I hope someone can at least point me in a direction, Im totally lost!
Thanks,
Dave

Edited 1 time(s). Last edit at 07/18/2016 11:20AM by virgodave61.

The fuses set various cpu modes and options one of which is jtag. If this has not been disabled then the pins that are connected to the jtag pins will not work as they should.

All atmel based controllers have fuse settings (well all that I've see so far)

You do need an external programmer to fix this, but you can use another atmel device

See [www.arduino.cc] for how to turn your UNO into a avr isp (note the extra capactitors for a UNO)

Next read up on avrdude (command line tool that is the back end of the ardunio ide [www.ladyada.net]

With this you can read the current fuses and set new fuses

To work out what the numbers mean, plug them into [www.engbedded.com]

If jtag is enabled de-select it and write the new fuse values back.

Edited 2 time(s). Last edit at 07/18/2016 05:45PM by Dust.

Thanks Dust,
I will look into this.
Dave