Electrical Potting for the Core

Hardware
1

Hi,

Does anyone have any experience with potting the Core? My primary concern is with Wi-Fi range. I’m going to go ahead and perform some initial experiments with it but wanted to know if there are any best practices in the community around this. I’m new to potting. The product will be going into an outdoor (potentially salt-air) environment.

Thanks,
mauricio

2

I’ve had lots of experience with 3M DP270 potting compound for sealing up cable assemblies and potting electronics. You want to avoid it coming into contact with certain kinds of non-fire retardant rubber or certain types of silicone though… which will prevent it from curing fully.

http://www.digikey.com/catalog/en/partgroup/dp270-clear-and-black-epoxy-potting-compound-adhesive/35822

You can get away without using a static mixer tube and the ratcheting handle assembly, but those two make life super easy. So if you are going to be doing a lot of this, pick those up as well.

Make sure all of your connections are soldered before potting. Don’t try to pot over any type of connector, it will work its way in between your connection points.

You can speed up the cure time by elevating the temperature of the environment, which helps if you have a lot of these to do. Check the datasheet for appropriate temps.

Alternatives for an outdoor Core project might be a NEMA 4x water tight enclosure.

Good luck!

1 Like
3

Thanks for the quick reply!

I understand your point about the connector. That is a pro-tip.

So I can’t rely on the USB connector being brought out for future programming / flashing (e.g. leave a connector plugged in and then pot). I could unsolder the connector and solder leads to the USB pads. Any other places for me to get access to those pads on the device? I don’t see anything obvious in your pinout diagram.

Thanks!
mauricio

4

The pads of the USB connector or the 22 ohm resistors would be ideal on the Core. The Photon will have data connections as pads on the bottom of the board centered on a 0.1" grid right under the USB connector.

If you bring the USB connector off the board though, it should go to a water tight USB connector… and the power source will need to be water tight/resistant/proof. An enclosure may be easier over all?? They make a lot of panel mountable water proof connectors. Just some thoughts… keep us updated on your progress :smile:

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