Multisensor PIR based on IKEA Molgan

[danta]

Did someone succeed in fitting a pro mini and radio in the Molgan while still using the original pir?
It looks to me there isn't enough room for the additional components and I'm not sure what part of the pcb I can saw off while still being able to use the original pir.

Does anyone have an idea?

[dynamite]

@danta
Fits.... Ok i need to attach the wites but it will still fit. The NRF can be placed on the other side

[Sander Stolk]

Bought 3 pcs. to open / modify / try fitting things in it. The thing is that this housing is really perfect to place it on the ceiling or to fit things in. Better than a black box.
What I'm going to try is remove all the plastic inside including the batteryhousing but not the "click"-system to mount it.
I'm going to try to make it 230 volt compatible with a HLK-PM01 so that I can use it as a PIR, Temp and door sensor and connect it at the ceiling.

Let you know how things are working out!

[Yveaux]

@Sander-Stolk said:

door sensor and connect it at the ceiling

???
My house has its doors in the walls...

[Sander Stolk]

@Yveaux said:

@Sander-Stolk said:

door sensor and connect it at the ceiling

???
My house has its doors in the walls...

Well... connect a very small white wire in the hallway to the top of the door with a magnet.
With white ceilings you can put little cables like out of sight

[Yveaux]

@Sander-Stolk ah, OK. I think you can even run it all on batteries if you want

[Sander Stolk]

@Yveaux Yes it can BUT...
I have 0 succesfull attempts with a APM with removed regulator on 2 AA batteries. For some reason it draws power and within 3 days my batteries are dead. It's something that I will ask on the forum in a while but for now this works all the time so for it is the easy way :)

[tomkxy]

Here is my a picture of my modded version . I used a Sensebender which is perfect for that use case having already a ATSHA204 and temp/humid sensor on board.

[tomkxy]

I put a more complete write up of my mod from the previous post on my blog including the link to the sketch.

[dynamite]

@tomkxy Nice write up of the "conversion". One remark to save some time... instead of removing R12 to R16 you can just remove R17 ... same result less effort.

[tomkxy]

@dynamite said:

@tomkxy Nice write up of the "conversion". One remark to save some time... instead of removing R12 to R16 you can just remove R17 ... same result less effort.

Thanks for pointing that out!

[TimO]

@tomkxy Nice write up! Do you have an idea on the accuracy of the humidity sensor within the case?

[tomkxy]

@TimO said:

@tomkxy Nice write up! Do you have an idea on the accuracy of the humidity sensor within the case?

I just put it up in my one of my rooms. It works at least at a distance of about 4m. I will try to do some measure at what distance it is working. I'll post the results.

[tomkxy]

@TimO said:

@tomkxy Nice write up! Do you have an idea on the accuracy of the humidity sensor within the case?

Sorry, just saw that you asked about the humidity sensor. No, I have no idea yet. Need to make some comparison measures.

[korttoma]

@tomkxy did you really need the voltage divider? I think the sensebender does a decent job of measuring battery percentage by default.

[dynamite]

@korttoma As far as I can see the sensebender is fed by the 3 volt of the PIR. So you can not use this as a reference for voltage measurement.

[dynamite]

@TimO @tomkxy I have the Dallas sensor within the case. The reading follows the same line as other temp sensors within the same room. No big delay or something. The only downside is that the PIR is mounted on the roof, so temp is always a bit higher.

[tomkxy]

I just realized that I see a lot of false triggers. Anybody else having that experience? Any idea how sensitivity of the PIR can be reduced?

[dynamite]

@tomkxy You can change the sensitivity of the PIR. You have to change the value or R15. See here for a datasheet of the BISS001
But I do not know whether you should increase or decrease it...?
If you did not modify your PIR then the PIR will stay high for 30 SEC. What is the period between the false triggers?
Could it have to do with powering your sensebender from the powersource within the PIR and not directly from the battery?

[tomkxy]

@dynamite I see no clear pattern for the false triggers. Most of the time it is after about 7 minutes. But not strictly. Sometimes more than a half hour.. Well if I would power the sense bender directly from the battery I either would have to use a regulator or remove one of the batteries. Would the PIR still work reliable with about 2.4V? Would it make sense to try a capacitor between the 3V where I power the sense bender from to ground?