prusa i3v automated power on/off

I've been reading around a bit and now it's time for my own post. I thought I'd ask about this to make sure it is reasonable. I'm thinking about making some sort of power switch that is controlled by some sort of logic reading from the printer. Something like an arduino reading the temp on the hot end and powering down the printer when the temp change is -180c (230 to 50 during the cooling after the print) or something like that. Is that reasonable or just too much? I don't much mind the ramps and mega being on. It's really just the fan that annoys me. I have a hexagon that requires the fan to be on during all printing. Maybe I can just install a normal power switch and then find a way to shut down the fan at that temp since it's probably more doable in marlin than the other option. What do you guys think?

In my opinion, i don´t know of it possible, you can read if any job is sending from the Arduino to the extruder, if not, you can had an entry to count time and then power off.

It is fairly easy in Marlin and Marlin already supports power supply control. You may ahve ot add a bit to do what you specifically need.

If I were doing it then I would add my own Gcode in Marlin for shut down (unless it has one already) then add that to my end.gcode file.

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Originally Posted by Mjolinor

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If I were doing it then I would add my own Gcode in Marlin for shut down (unless it has one already) then add that to my end.gcode file.

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- I Agree, simply make a custom GCode to achieve powering down or shutting off that particular fan. I would code it using a M109 so it waits for the temperature.

M140 S0 ;Turn off the heated bed
M109 T0 S50 ;Waits until it reaches 50C
M104 T0 S0 ;Turn off extruder
M107 ;Turns off standard cooling
M### ;Your custom GCode HERE

gcodes M80 and M81 are available in Marlin for power control, assuming the hardware is set up to deal with the associated power supply control signal (logic is on a constant power source, external relay or ATX power supply is being used for the rest). The power off, however, doesn't factor waiting until any of the temperatures are below a threshold. I'd prefer to wait for the hot end to cool down some before killing it's cooling fan. The easiest thing to do would be to increase the delay built into the M81 code, or preface the M81 shutdown command with a G4 dwell command to wait some number of seconds first.

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Originally Posted by GOC

- I Agree, simply make a custom GCode to achieve powering down or shutting off that particular fan. I would code it using a M109 so it waits for the temperature.

M140 S0 ;Turn off the heated bed
M109 T0 S50 ;Waits until it reaches 50C
M104 T0 S0 ;Turn off extruder
M107 ;Turns off standard cooling
M### ;Your custom GCode HERE

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Will M109 work for this? I think it will only work waiting for a temperature setpoint higher than the current reading.

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Originally Posted by printbus

Will M109 work for this? I think it will only work waiting for a temperature setpoint higher than the current reading.

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- I don't use Marlin, so I can't say for sure. It works on my Orion Delta, it moves to the next line once it gets within 2-5deg of the target.

- I figured it was the same for Marlin since the M109 code has the 'tempmin' & 'tempmax' variable associated with it.

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Originally Posted by GOC

- I don't use Marlin, so I can't say for sure. It works on my Orion Delta, it moves to the next line once it gets within 2-5deg of the target.

- I figured it was the same for Marlin since the M109 code has the 'tempmin' & 'tempmax' variable associated with it.

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Interesting. Looking now, I see there's more capability built into M109 than I was aware of. It looks like M109 R50 might be what you'd do on Marlin to wait for the hot end to cool down to 50 degrees.