A new all-in-one sensor


All-in-one sensor

Large sensor? Neh, I don’t think so; the image above will probably display the enclosure larger than life – well, on my 23″ screen it does ;-) The dimensions of the enclosure are 44 x 30 x 16 mm and it houses a PIR, a Maxim DS18B20 and a LDR.

Motion, Temperature, Light. That’s what I think I’ll need for my new sensor. Humidity will be left out; although I do have humidity sensors in my house, I don’t use them that much. For the bathroom a humidity sensor would be nice, but not for the rest of the rooms upstairs. Cause that’s where this new sensor is going to be used; at least 3 of these, one for each room and a slightly different version for the bathroom.

I’ve used this enclosure before with other PIR sensors, but this time I wanted to see if there was enough room for some more; I must say, it’s a bit crowded inside the enclosure now. The PIR has a PCB whose dimensions are 32 x 24 mm and it has lots of components, so I really need the 16 mm depth of the enclosure.

The PIR I’m using has a detachable lens, so after carefully measuring where the center of the 12 mm hole should be drilled through the cover of the enclosure, I could stick the PIR through that hole and put the lens back on the sensor. I did have to cut away some wires on the PIR side of the PCB, cause otherwise the distance between the PCB and the top cover of the enclosure was too large. After that, the PCB was glued to the top cover of the enclosure.

For the 1-Wire DS18B20 and LDR I drilled 5 x 0.5 mm holes, put the legs of these 2 sensors through the holes and fixed the legs with a tiny drop of glue, just enough to keep them in place. The housing of  the DS18B20 sticks out of the enclosure very little; you don’t see the legs sticking out. The LDR sticks out a bit more, so that the LDR won’t be hindered by any shades from the DS18B20.

What's inside

Well, that all for now – now I’m facing the fact that I have to solder these 3 sensors to a single cable that has to enter this crowded enclosure somewhere… phew, what am I getting myself into?.. I hope this won’t get too messy :-)

 

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10 Responses to A new all-in-one sensor

  1. Wilco says:

    Nice, is it possible to make a picture of the insite?

  2. Kyle Gordon says:

    What board is that you’ve got in there? I’m looking to make just the same sort of thing, but for outside use. :-)

    • I can’t tell you where to buy it, cause I got the PIRs from a friend and I don’t know where he bought them. But this looks much like the ones I have. Look for PCB size of 24 x 32 mm, BIS0001 chip on the PCB and a potentiometer to adjust the delay time. Or maybe this one is OK for you.

  3. Kyle Gordon says:

    Ooh, that’s good to know. Thank you for the pointers :-)

  4. Jeroen Cornelissen says:

    Hoi Robert,

    why didn’t u use the Roomboard from JeeLabs?

    Nice enclosure!

    PS: I really like the detailed info and frequency of your blogs, I really enjoy them!

    • Hi Jeroen,

      2 reasons. Well, actually I had only 1 at the time I decided what to use as ingredients for this sensor: I already had enough temperature sensors and LDRs for these sensors; the only thing missing item were the PIRs. And 4 x PIR is cheaper than 4 x Room Board…. And although the Room Board is small, it wouldn’t fit in the enclosure I want to use. And I always like to do things slightly different… now you have 3 reasons after all ;-)

  5. Gijs van Dulmen says:

    Hi Robert,

    I ordered the same enclosure a while ago for a lot of sensors over here. I also added a hole for the LDR. Connecting a cable (phone cable with solid wires) was indeed a bit tricky. I came up with cutting a very small piece of printboard which I soldered the cable on. I could put it over the male headers of the motion sensor and solder the headers to the board. Just like a small breakout board but without the space of the headers. Maybe this is the way to go … at least it fits inside the small enclosure :-)

    Greetings!

    Grt,

    Gijs

  6. Hey Gijs,

    Thanks for your input. I’ve been thinking today on how to keep this sensor as robust as possible regarding all the wires I have to solder inside the enclosure. I guess this will also be a matter of evolution, just like all the other things I built myself …

  7. Pingback: First sensor finished and working

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