Computing stuff tied to the physical world

Room Node mount?

In Hardware on Sep 21, 2010 at 00:01

I’m still searching for ideas to mount a JeeNode with a Room Board, a.k.a. as a “Room Node”. Now that the AA Power Pack lets me get rid of two of the 3 AA’s, I’m sort of hoping to bump into some new and practical options.

How about this position, against the ceiling?

Dsc 1957

The PIR motion sensor is placed above an empty spot between the JeeNode and the AA Power board. It’ll need to be wired up in that position, of course.

The shapes are still agonizingly unsuited for placement into a corner, but then again… it’s a lot better than with the 3x AA battery pack! Here’s the whole setup again, in close-up:

Dsc 1958

The trick will be to cover it up properly, here’s a first trial using my favorite foam-board as prototyping tool:

Dsc 1960

That’s 6.5 cm wide, btw. Any less, and the battery holder will poke into it and make it wobble.

Does it look good? I don’t know. I think I could live with a slanted 6.5 x 20 cm white strip along the ceiling, with a little PIR peeking out in the middle (and a small hole for the LDR + temperature/humidity sensor).

Next challenge is to come up with a mounting bracket for this darn thing. Perhaps 3D-printed? Two triangles on the end or something? If they slant slightly inwards, they would cast a shadow and not draw much attention…

It all needs to be properly detachable, since this thing runs on battery power. I could stick two little solar panels on the surface to get a warm fuzzy environmental feeling… but I doubt they’ll capture enough energy in that position.

Anyway – I’m happy to have a fresh option to think about. We’ll see…

  1. Hmm, Would it not take less space if you place the battery at the bottom? or better yet have a battery PCB where the AA fits in a cutout.

  2. It’s clear… size matters. It seems though that you don’t want to give up modularity. In most cases, where you want to optimize for size, you prepare a dedicated PCB (and you’re good at that !). I think changing to and SMD AVR, integrating all different board to one PCB (or multiple stacked) and reduce the number of connectors, this has great potential in being small.

  3. And idea on projected battery life with an AA and room node ?

    • Too early to tell – 6..12 months? I would like to revisit the “rooms.pde” sketch soon, and try to apply some new-found insights to it.

  4. Jeecoving?

    @Sylvain, if you are referring to having the battery at the very back, so it’s narrower width fits further into the corner, that is exactly what I was about to suggest.

    • @TankSlappa, yep, or even using a but of a cutout in the PCB to sink the battery further.

  5. @S & @T – it doesn’t reduce the space requirements as much as you might think. The current battery clips stick out in all the worst places…

    @P – Good point about shaping the board to the space, and integrating everything. So far, I’ve been keeping the JN at the center, because it looks like most people want the through-hole kit – which costs less than a pre-assembled SMD version. There are some substantial size gains to be had by going single-board (and single-purpose) SMD of course – the battery and the PIR sensor board then become the dominant components.

    • Could you use springs? But, why not use a dedicated battery pack? I guess you should be able to get them in a really small form factor

  6. How about putting it right in the corner of all three surfaces, then you wouldn’t have to worry about making a neat end, you would just have you cut an equilateral triangle.

    As for fixing it to the wall, what about some of those modern ceramic button magnets? Put some cheap steel (i.e. not stainless) screws into the wall and the board will just stick to them.

    • ceramic button magnets

      Great idea! Needs to stick well, of course – but it would be mighty convenient!

  7. Maybe two AAA’s ?.

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