Getting out of the box

[รอเรือ]

So you put your sensitive electronics inside a water sealed box (hopefully) you put it outside and unless you are interested to find out about the environment inside the box, you also connect some external sensors. That's where the water comes into the box, right?

So how do you normally do that? I use to drill a hole, put the cable through and use hot glue to seal it. It kind of works but it's not very service friendly in a scenario where you don't want to remove the sensors from where they were fastened.

I had a new idea today that I'll try. I'm sure that you guys have much better ideas about how to do this.

What I want is a way to disconnect the sensors easily so I can take the box inside for exchanging batteries, replacing software or whatever. Then I'd like to reconnect the sensors again easily. There is probably nice connectors out there that can be bought but they must be reasonable priced for me to use them.

[zboblamont]

@รอเร-อ Avoid external connectors where possible, corrosion or rain penetration are avoidable.

I use hinged transparent window (weatherproof light switch) boxes hacked out on the inside with a Dremel, and can lift the cover to reprogram or change batteries in minutes and close it up on site. A desiccator takes out any air moisture trapped from that opening.
All cables enter the base of the box through a grommet/seal tight around the cable or a 16mm cable duct foam sealed on the end, with internal connectors, and no issues with water entry at all.

[rozpruwacz]

do You really need to take the box to do those things ? Why not just take the board out of the box and keep all the connections inside the box. There is always an option to have water proof connectors but I think that they make more trouble than it's worth.

[zboblamont]

@rozpruwacz Completely agree, if the objective is to change batteries or reprogram, there are alternatives not subject to other than the controlled environment of the case.

As a postscript to my earlier post, one of my 5v Slave (sub) Nodes was assembled using female strips to connect the MCU holding it near the front transparent flexible face of the case.
The female strips are mounted on a slide out tray (actually the cover of a plastic conduit glued to the back of the case), the conduit holds the two AA batteries in a case for easy access and replacement.
The outcome is that the MCU can either be programmed in place using the sliding conduit cover to get the pro-mini clear of the case to use ftdi, or completely removed for external mods. Battery replacement should be easy enough, but haven't needed to do so yet...

[รอเรือ]

@zboblamont

You are right, it will corrode sooner or later. It's a bad idea. I'll wait until it's time to change battery or it stops working (whatever comes first) and then I'll make it according to your suggestions.

Would you like to show us with a photo how your nodes look like? Thanks!

[mfalkvidd]

I use this

[zboblamont]

@รอเร-อ It was posted earlier, but hopefully you can figure it out from the comments and photos.
The 5v SLAVE pro-mini is facing front, but is connected behind to female sockets glued to the duct cap including the offset I2C lines a4 and a5. The duct main body is a holder for the battery holders, for the SLAVE 4xAA, for the MASTER, 2xAA.
The conduit itself is glued to the base of the case, leaving the cap free to slide but not detach, the pro-mini is free to be detached when pulled from the sockets.
The MASTER has an onboard RTC so is not intended to be removeable. There is a permanently attached USB power cable to enable battery changes without losing the RTC......
Simple re-purposing of preformed plastics for alternative uses...
https://forum.mysensors.org/topic/9424/an-ultrasonic-measurement-saga-finally-over/2

[zboblamont]

@mfalkvidd Gland plugs are almost bulletproof, perfect for the selected diameter. The beauty of the free grommets usually accompanying cases is that they may be cut to size, whether that is an antenna or a cable conduit...