Looking for EAGLE part and pin mapping for Spark P1

I found some details for the WM-N-BM-14 here:

http://www.cnblogs.com/shangdawei/p/3485122.html

Anyone has an EAGLE part for the same? Also, some pin mapping information along the lines of what Spark has published for the P0 here?

@zachary I think these would be useful for folks who want to get started with a PCB design using the P1.

Thanks

Thanks for the request @electronut! We’re working on this — it’s currently in @BDub’s court (or else he’s waiting on a response from someone else). I’ll leave it to him to update this thread when there’s news. :+1:

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Thanks!

That repo currently holds some eagle files already - is this what you’re looking for?

edit: Got it, those are for the full Photon boards

@electronut please check out the P1 / WM-N-BM-14 EAGLE library files and pinmap spreadsheet I just pushed to the Photon repo: https://github.com/spark/photon/commit/4505310

:sun_with_face:

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Thanks for this! Traveling now, but will check it out next week.

That’s a LOT better of a footprint than the Electric Imp IMP003. That 003 was designed by sadists who hate hobbyists and their petty hobbyist tools.

But the pads are still underneath for the P1, correct? Is it possible to solder these without putting them through a reflow oven?

No, unfortunately I do not know of any way to get solder to pads under the module. :frowning:

No, but a local hacker/makerspace will probably have a reflow oven and the expertise to help you when soldering.

Also, I am certain that someone will sell P1 breakout boards soon after the P1s start shipping.

I would have liked to have seen a ‘hobby board’ version of the photon. Sort of like the current photon but without the power regulator (that I don’t need), the USB connector, buttons and RGB LED. It would have the extra pins along the top of the module for the buttons and LED.

This would give me an easily solderable package, but allow me to move the buttons and the RGB LED to better locations on my board. Using the Photon as as is, forces me to enlarge the size of my board and have some awkward compromises.

I’ve been able to solder some network chips and power regulators that have ground pads on the back of their package using a hot air gun and low temperature solder paste such as:
http://sra-solder.com/chip-quik-low-temperature-lead-free-solder-paste/

I don’t think it’s possible to solder the P1 with its 9 pads underneath with this method, without a stencil and a reflow oven. That’s what is holding me back from purchasing the P1.

@StuartK You may want to consider the hot plate method for reflow soldering. From what I have seen on the web it seems like a possible solution for you.

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Last night I was touching up some individual pins of a P0 module (read, smaller) with just my Hakko soldering iron. The way I did it was to scrap some of the soldermask off of the traces running away from the pads which allows you to apply heat to the copper. Then you can carefully feed in very thin solder.

If you wanted to do this better though, you could modify the footprint to extend the pads out far enough to get your soldering iron on the pads. Then you would tin the pads on the bottom of the P1 evenly (apply and remove solder with just the tip of the iron). You would also tin and completely remove solder from the PCB (apply and remove solder with solder wick). Add flux. Push down your module around the outside edges, tack the corners… then solder each pin one at a time. To get to the 9 GND pads in the center soldered… you could put some what large enough plated vias under them that allow you to “see” the pad from the bottom of the board. You could apply heat to the via with your iron and see the solder reflow on the pad, then add more solder filling up the hole. All GND planes should be thermally relieved for hand soldering, or you will not be able to apply enough heat to reflow the solder.

I think the electric skillet is a great choice though… however… you still need a good stencil as well.

It isn’t terribly difficult to design a board such as this given that the Photon is open source. I was planning on doing something very similar for myself just so I could get more Eagle practice once the final design files are out.

If you can be specific about what you want moved off-board, maybe I can add this to my list.

Buttons, RGB LED, USB connector, voltage regulator… Anything else? Note that USB is differential and that moving the connector off board via a breadboard probably won’t work very well. I’d rather leave this onboard, and use a USB extension cable to break it out.

Thoughts?

Hi BDub,

That idea with the via’s actually makes sense. I’m for the most part using 8mil traces with 10mil drills in my project, which I’m guessing would be difficult to solder through. What size drill would you recommend? I imagine you might need a 20mil, but it may be too big for the pad.
Do you recommend running a ground fill with thermal relief under the module or just pads? I’ve noted that you don’t want a ground fill under the antenna component.

I have to admit I’ve never tried the ‘hot skillet’ method.

Hi Naikrovek,

For my current project, I’m using a Pic32MX795 which is 3.3v already so I don’t need any of the power supply components. I guess the USB connector might be useful for debugging, although I plan to do all the debugging with the core on a breadboard prior to assembly and so its redundant for my needs.

All I really need on the final board are the module, antenna, similar to the P1, but just in a more easily solder-able format.

I’m guessing a lot of people would like an easy solder P1.

Looking at the P1 briefly, I think some 40mil drills with 10-20 annular ring could possibly work. These are through holes like those used for the header pins. Why so large? So you can see in there if you’ve actually connected the pin to the hole before you fill it up. There is a lot of room around those PADs on the P1 for all of the other signals as well, so you shouldn’t be too bothered by the fact that there is a little island of GND through holes in the middle. This is not super ideal I know, but you wanna hand solder it… so this is a way I can think of :smile:

Yes put GND plane wherever you can fit it in, except for the area around the antenna that is a restricted keep out. Try not to create orphans, and if you need to… stitch them down to GND on another layer.

Is it possible to also add to the pinmap, showing what the other pins mean, like what GPIO is a D1, D2, A1 etc. Also what pins would be USB, what one is the mode button? I am trying to get a jump start on a pcb design using the P1, but Im not certain what pins on the P1 map the the firmware functions.

Any help will be much appreciated!

Thanks