Doing Filament Change Command (M600) using limit switches

[DarkAlchemist]

I wish I had a RAMPS board, but I have a PrintrBoard. However, that really doesn't matter. You just need to find an unused GPIO pin on your board and wire a switch to it (and declare that pin for use by the firmware). It is pretty straight forward to check if you have the switch wired up correctly. If you decide to do that, I'll help you get the M600 code working on your board.

My ramps had no pins so I had to add them for the ABL but what a PITA getting all of those wires back on for the motors etc... I never added the ones that didn't have anything to do with the servo. Every time I take that off I always end up missing a wire when I put it back together.

Why do I need to wire something else up to get M600 to work?

[Roxy]

My ramps had no pins so I had to add them for the ABL but what a PITA getting all of those wires back on for the motors etc... I never added the ones that didn't have anything to do with the servo. Every time I take that off I always end up missing a wire when I put it back together.

Every picture of RAMPS boards I've seen have lots of GPIO pins sticking up to put other boards on. If you don't have dual extruders, I would think there should be extra GPIO pins on the Arduino board that would handle that if it was plugged in. In that case, you just plug a wire like here and run it to a switch:

http://www.ebay.com/itm/10pcs-Female...item4d1baa25fc

Why do I need to wire something else up to get M600 to work?

Because the Arduino can't read your mind and know when the filament change is completed. It needs you to tell it that everything is done and it can continue. If you wanted to be really lame, you could look at one of your limit switches for one of the axis instead of a new switch. But connecting up a switch is really pretty simple and a better way to go.

[DarkAlchemist]

Because the Arduino can't read your mind and know when the filament change is completed. It needs you to tell it that everything is done and it can continue. If you wanted to be really lame, you could look at one of your limit switches for one of the axis instead of a new switch. But connecting up a switch is really pretty simple and a better way to go.

That is precisely what I was talking about as this dude on Youtube had Repetier do that without any extra hardware or wires. What he did was press continue and it went back to where it was and continued and he said that was built in to Repetier. Well, that isn't in Pronterface sadly. Continue is there but it is a continue where you left off not a continue on a M600 going right back where it was and continuing with the new color.

[Roxy]

OK... I understand your problem! You could try just heating up the one pin where you want the connection and inserting a wire like this:

http://www.ebay.com/itm/40pcs-20cm-M...item20ef967429

But... If you want, we can make a small change to the firmware to watch which ever limit switch you want to use. What would happen is the printer would get the M600 filament change command and do its thing. After you get the filament changed and the nozzle purged of the old filament, you would press and release the specified limit switch. And everything would continue on its way. Do you want to try that?

[DarkAlchemist]

OK... I understand your problem! You could try just heating up the one pin where you want the connection and inserting a wire like this:

http://www.ebay.com/itm/40pcs-20cm-M...item20ef967429

But... If you want, we can make a small change to the firmware to watch which ever limit switch you want to use. What would happen is the printer would get the M600 filament change command and do its thing. After you get the filament changed and the nozzle purged of the old filament, you would press and release the specified limit switch. And everything would continue on its way. Do you want to try that?

Sure. Eventually I will get those other pins wired up with the header pins as I had to do for ABL but frankly I had it all installed and did a Homer Simpson DOH! when I noticed I had forgotten those digital and analog pins. With those added adding another switch would be easy.

[Roxy]

Sure. Eventually I will get those other pins wired up with the header pins as I had to do for ABL but frankly I had it all installed and did a Homer Simpson DOH! when I noticed I had forgotten those digital and analog pins. With those added adding another switch would be easy.

Which limit switch is easy to get at when you are standing over your printer?