On/Off Switch (In Software)

[bill.gertz]

Hey all,

We were able to 'hack' in the supported Power switch using the PS_ON header point on the RAMPS v1.4 board. All you need do is solder a three pin header near the reset switch. The header solder points are labeled PS_ON, 5v, and Vcc. To make it fool proof we actually soldered pins only to the PS_ON and 5v pins on the RAMPS board.



Then we attached a three pin connector to the green wire coming from the ATX power supply (PS_ON). We plugged the point corresponding to Vcc on three pin connector - this makes sure that you couldn't get the connector turned around.



This really isn't a hack, as it is supported both in Pronterface and Repetier using the Marlin firmware. When you hit the 'power' button it actually sends an M80 (on) or M81 (off) command to the printer. The firmware then brings PS_ON low (turning on the power supply) or high (turning it off).

You can verify that everything works by hitting the 'Power" and 'Fan' buttons on the 'Print panel' tab in Repetier Host - the extruder fan should happily spin on...

Good luck with your modding,

bill.gertz

[Kjetilei]

Thanks for the tips!

I suspect that the reason you used a 3 pin header is that that was what you had at hand since only the PS_ON header is used.

I'll most likely end up only soldering the PS_ON header.

[aikx]

Thanks, this works fine!
But in Repetier-Host sometimes first the "Fake OK" should pressed.
An switch in the "green"-line would be a "Stop any operation"

[HLA]

Thanks for this.

I guess we could additionally include a harware switch for the green wire as the main power switch for the printer?

HLA

[bill.gertz]

HLA,

Yes you could but you would need to use a SPDT (Single Pole Double Throw) switch. The green wire (PS_ON) is soldered to the center pole, one throw is soldered to a wire that goes to PS_ON pin on the RAMPS board, and the other throw soldered to a wire that goes to a red wire (+5 V). This would override the PS_ON setting in software (switch PS_ON throw) to high logic (switch +5 V throw). Since the PS_ON for the power supply is active low, setting it high will turn off the power supply.

Not that you didn't know all of this, but I'm writing for new Felix Printer users who want attempt this mod of a mod...

Regards,

bill.gertz

[Kjetilei]

I finally took the time to implement this mod and it works like a charm!

I used some left overs from a R/C receiver and R/C ESC and soldered all three pins for stability but double checked pin placement before I fired up the printer.

Thanks bill.gertz!

[bill.gertz]

Kjetilei,

Glad it worked out for you. I'm now working on adding an SD, LCD, and emergency stop button to the printer. When I'm done I'm going to post to the thread started by HAL: http://www.felixprinters.com/forum/view ... p?f=9&t=33. This will require a further mod - I'll need to add back the Vcc pin that I removed and connect that to the ATX standby power (Vsb) using the purple wire . Please at that thread to see how it all turns out.

Happy modding,

bill.gertz

[satoer]

Thanks, works perfect!

[satoer]

Well, turns out the hack isn’t total bug free. If you unplug the USB or sometimes when I shut down my computer the Felix power supply turns on. So the USB needs to be all time powered otherwise the power supply turns on.

[Kjetilei]

It's annoying but I have gotten used to it and the mod means less wear on the power plug. But I suspect that I'll have to remove the mod when/if I add a LCD/SD module.