Azteeg X3 and external Mosfet connect-up Question...

Hi folks,
The Azteeg X3 has what I read are "lower power switched mosfet outputs", four of them, marked D4, D5, D6 & D11 (length ways) and 12v, sw, 5v (inwards), on the board. See photo curtsey of Panucatt.com (the red arrow is mine ) Wiring Diagram here.


I have already connected two low powered 12v fans utilising D4 and D5 positions, by connecting the fan (-) wire to the SW Pin (middle pin). The fans get their 12v feed piggybacking on the 12v line to the hot-end. This all seems to works very well (Mendel 90 self-build printer by the way.).

I want to power and control a much larger fan now! This is to cool the finished prints, and would be switched on by some End Gcode. The fan I want to use is 12v 0.58A.

I think this fan would draw too much power through the "low powered switched output" so I would like use a direct 12v supply from the PSU, and just switch the fan on/off from the board. I read I should utilise an external mosfet arrangement and have built myself a little "cooling fan mosfet driver"...as found on Thingiverse.

I've tested my little board (photo above), separate to everything, 12v to Red, GND Black, give the Green Signal wire 6v and the fan comes on.

My question is how might I connect this up so the Azteeg board drives the big fan via this mosfet board?
If I connect the Signal wire (Green) to the SW Pin on the Azteeg board, and connect the Black (-) and Red (+) wires to leads from the PSU then nothing will happen.
Should I supply 12v directly from the PSU to the Red (+) wire on my external Mosfet board, and connect the Black (-) to the Azteeg SW Pin (D6), and the Green wire to the Azteeg 5v Pin (D6)? This will switch the fan on I think, but I'm concerned that this would run higher current back through the Azteeg board, which is what I'm trying to avoid.

Any advice or clarification welcome. (Excuse my poor understanding of the electrical/electronics dimension.)
tks,
Ivor

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[numbersixreprap.blogspot.com]

I don't think you can connect that board directly to the switched mosfet output. It is designed to connect to a digital output, there should be a spare pin on one of the expansion headers.

DC current. The V+ connects to one side of a load, that is called high side. The GND connects to the other side of the said load, that is called low side. In mosfet the gate voltage determines a current flowing from drain to source. So for low side switch, top side with V+ goes to load top, and low side with load goes to drain, the gate goes to uC, and source goes to ground.

Reprap is open source community. It is called like that because the source files are available for download. If i am not mistaking your board is made from some guy who copied from other open source electronics and released its variant as closed source, that means the source files for that board are not available. I am against that and i think that it takes a special kind of ppls to do stuff like this. Source files are *extremelly* important when you want to do any mods. With source files for example, you highlight a net, and shows all of it, you know which path it goes, where its easiest to hack etc. Its also much easier to get help from others if anything goes wrong or if you want to expand is functions etc.

So if you get in a domain that is open source, then buy that: electronics which give a link to source files. Without source files: *dont* buy, no matter how cheap it is or how good the marketing was, and no matter how much the guys was bragging about himself, and no matter how shiny the top lid is. So imho best thing to do from now on - stick with open source, if you want to learn, understand or hack things.

@ Noobman - it is open source, but I do need to spend time cleaning up the schematic/PCB files so it can be easily understood and actually posting it. I do send them out when someone asks for it in its current messed up state. I will update the web page to include those files( and wiki page too). The Azteeg X1 files were posted pretty quickly since thats the only project I have going a that time. Thanks.

@NumberSix - Easiest way is to just use one of the 2 extra Mosfets on the top cover ( if you're not using them), they can handle your fan easily. See 2nd page of wiring diagram for digital pins used. If you dont have that version of the cover, PM me.

Hi Roy,
Thanks for the prompt response. I do have the cover as in the pict above, so I'll try my fan in the H-END3 (D16) connector as you suggest.

One final question... In Marlin do I simply change the "-1" to "16" in the " #define HEATER_2_PIN -1 " line, in Pins.h tab (MOTHERBOARD == 34 section)?
What g-code command will switch on the fan? I presume M42 P16 S255?

Thanks again!
Ivor

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[numbersixreprap.blogspot.com]

royco Wrote:
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> @ Noobman - it is open source, but I do need to
> spend time cleaning up the schematic/PCB files so
> it can be easily understood and actually posting
> it. I do send them out when someone asks for it in
> its current messed up state. I will update the web
> page to include those files( and wiki page too).
> The Azteeg X1 files were posted pretty quickly
> since thats the only project I have going a that
> time. Thanks.

Ok, i can relate to that because i take a lot of time to do anything, and i'm like always late for ... anything. And i dont want to be combative or anything like that, im only trying to be realistic. Its been ~1 year since your last change to wiki page and still no source, so past any delays, to say its overdue is understatement. And this situation can be only one way or the other, cant "sit on the line", its not a "shades of grey" problem. Its black and white, it can be open or otherwise its closed. Its open if the sources are available for download, else its closed. Sources doesnt have to be clean or anything like that. Doesnt matter its quality, all that is beyond the point. Sources just has to be there for download, thats all. Atm is closed untill you post the sources, e.g. make them "open" for download.

I can ask in emails for sources files of sort of any evaluation boards, like from ti, or maxim, and kinda any major companies may provide such, if asked nicely, simply because they are "pushing" the associated products. But this "upon request" doesnt make them "open source", since a "private" exchange of files. Not public, therefore not "open".

I dunno if its the case, but i can make another suggestion if i am allowed to. If you dont want to provide the specific source files, at least export the files into another program like geda, kicad, expresspcb or something alike, and publish that version. The open ones have formats that can be seen and checked entirely with just a text editor - that is if you want to check their content you can do that letter by letter. You can even say openly "we have sources in some other program but decided to export and make them available in this other format". Thats ok. Even if its said its not *the* source, at least its something that can be taken as such, provided some eventual exports mishaps get fixed and it compares well enough with the board in hand. When modding/hacking or asking questions, such files are golden. Its still something. It can be worked with. A user can ask a question attaching those files. Or most perhaps wouldnt needed to ask this question if he opened such files himself. He could of easily highlight and see any digital trace from uC to the connectors, and that might of been enlightening enough.

I understand what i am saying are probably not the words you want to hear, but what do you expect me to say to OP, should i say "yes from the picture that *looks like* its a digital line"? and you "lets *pray* it doesnt have some other components linked to it for some other purpose". Under the circumstance i tried to give my best advice which is "check for sources first, coz we dont get to know whats *really* there without them". Well, thats me, its only my opinion ofc and nothing more, may it be good or bad, nothing is absolute, an opinion even less so. Cheers.

I got what your saying, I'll get the latest files out there. Like the X1 I will be posting Diptrace and PDF files. I dont know how to use Eagle or other schematic design program so it would be a real stretch for me converting or recreating at this time.

But I do have to clean it up, some parts dont have values or worse incorrect ones. Production BOMs are built on a separate spreadsheet. So a lot of updating and checking is in order.

@NumberSix - Yes, you could treat them as those other PWM pins D4, D5, D6 & D11.

Thanks

Royco,

"Files and Documentation: Apparently the source files for this board are not available, so this electronics seems to be closed source. Beware, this is pretty much against the open source philosophy of reprap. Also the lack of open source files may increase the difficulty of getting help for troubleshooting, hacking, expanding etc."

Quoted from [reprap.org] (linked in your signature)

Note: I am researching what controller I will be using in a delta build and noticed this. You may want to update wiki when you clean up and publish all the files.