💬 Multi-Sensor: Temp/Humidity/PIR/ Leak/Magnet/Light/Accel

[Nca78]

@NeverDie said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

Thanks for the suggestion. What would the hall sensor be used for?

For a door sensor. This PCB is small enough to be hidden inside a door edge, if you put it on top with a small magnet in the frame it's completely invisible and you've got that mythical 100% WAF level :D

There is a cheap version, TLE4913 that's available on AliExpress (less than 2$ for 10 with shipping), it's consuming around 4uA so it's not extremely energy efficient but you can't beat the price on AliExpress.
https://www.aliexpress.com/item/in-stock-can-pay-TLE4913-4913-SOT-23/32823499977.html

Then there's the DRV5032 from TI that had the lowest power consumption a few month ago when I bought it, it's 0.5$ on Arrow and needs only 0.54uA in the FB (5Hz) version
https://www.arrow.com/en/products/drv5032fbdbzr/texas-instruments

And now I see the si7201 for 1$ on Arrow, using only 400nA.

My choice would still be for the DRV5032, but the good news is all those sensors are using the same package with the same pin assignment. There are a few others (including one that scalz used in one of his design) also with the same pin assignment.

[NeverDie]

Hmmm.. I don't presently have a need for a door open/close sensor. However, if I could use it to tell me whether the deadbolt is locked or unlocked, that would be useful.. Maybe if I epoxied a magnet on the tip of the deadbolt? Or is there some other, better way?

[Nca78]

@NeverDie said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

Hmmm.. I don't presently have a need for a door open/close sensor. However, if I could use it to tell me whether the deadbolt is locked or unlocked, that would be useful.. Maybe if I epoxied a magnet on the tip of the deadbolt? Or is there some other, better way?

Yes you can use it for that. Maybe magnetizing the deadbolt could work too ?

[NeverDie]

There may be enough space within the deadbolt lock cavity itself to mount a wireless sensor there. It's something I've wanted for quite a while but until now I've never had (and couldn't find) something small enough to fit in there.

[NeverDie]

@Nca78 said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

Maybe magnetizing the deadbolt could work too ?

Great idea. :)

[NeverDie]

@Nca78 said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

There are some 2x5 1.27mm IDC connectors on AliExpress here but they have smaller inside space than the one you choosed so I'm a bit worried...
https://www.aliexpress.com/item/20Pcs-0-050-1-27-mm-2x5-Pin-10-Positions-IDC-Male-Box-Header-Dual-Row/32813323776.html

Those are thru-hole, not SMD.

I actually prefer thru-hole for these 10-pin connectors--much easier to solder--but I'm afraid the resulting solder/pin bumps on the back side would make the CR2032 holder sit a bit crooked (?), if you know what I mean.

That said, I've found buttoncell holders that have little plastic alignment pins on them (meant to fit into alignment holes) that could jack up the holder a bit if the alignment holes were omitted. Maybe then there'd be enough clearance.

[NeverDie]

@Nca78 said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

Would you consider changing the pads for the SMD header to this ?
http://www.molex.com/pdm_docs/sd/878980426_sd.pdf
This is what is recommended for this header that's available on Arrow, meaning free shipping for most of the world, as opposite to Digikey asking me for 75$
Product on arrow is here. It is in fact smaller so it should fit on the pads you have put, but I suppose it will be easier to solder with the bigger pads.
https://www.arrow.com/en/products/0878980426/molex

Yes, but what's holding me back is that I'm worried I might plug it in backward and possibly fry something. Haven't really thought it through though. Maybe there's actually no risk if that were to occur? The one and only advantage of the box header is that I can't accidentally plug it in wrong.

But I've been thinking along similar lines. I've already ordered and received this from your favorite source:
https://www.aliexpress.com/item/25-pcs-2x5-P-10-Pin-1-27-mm-Male-PCB-Header-Dual-row-Straight-PCB/32762274575.html?spm=a2g0s.9042311.0.0.ltfMrU

and

https://www.aliexpress.com/item/20-Pcs-Per-Lot-Pitch-1-27mm-Female-2x5-Pin-10-Pin-Double-Row-SMT-SMD/32591554432.html?spm=a2g0s.9042311.0.0.ltfMrU

@Nca78 Would those be equivalent to the Molex that you linked to, or would the Molex you linked to be better?

[NeverDie]

@Nca78 said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

This is what is recommended for this header that's available on Arrow, meaning free shipping for most of the world, as opposite to Digikey asking me for 75$

In any event, these should work the same as the Digikey ones: https://www.aliexpress.com/item/10-Pcs-SMT-Box-Header-1-27mm-2x5-P-10-Pin-dual-row-Straight-Male-surface/32787313045.html?spm=2114.10010108.1000013.3.2b0cc1askqPA1&traffic_analysisId=recommend_2088_2_90158_iswistore&scm=1007.13339.90158.0&pvid=a04bdf37-bc7e-4b9e-850f-b5e285ab3ff0&tpp=1

[NeverDie]

Also, there may be a clearance problem with the current PCB layout. Not sure if a si7021 or BME280 were installed whether or not it would overlap or collide with the 10-pin box connector. So, that may be yet another reason to do a Version 3.... Didn't notice it as a possible problem until after I had posted Version 2. A workaround would be to install the si7021 or BME280 upside down, so that the board points outward rather than inward. That might be acceptable also. It would somewhat defeat the compactness objective, but the antenna has to stick out a bit anyway, so that's already happening to some degree.

[NeverDie]

Does anyone know where we can get the connector that's used on the nRF52 DK? It would seem to be ideal: 10-pin, and keyed, but no box surrounding it.

[NeverDie]

Aha! Found one: https://www.digikey.com/product-detail/en/samtec-inc/FTSH-105-01-F-DV-K/SAM8796-ND/2649974
Not cheap on Digikey though.

[NeverDie]

Also, since the back of it is almost entirely ground plane anyway, it seems ripe for using a smaller profile CR2032 battery holder, such as: https://www.digikey.com/scripts/DkSearch/dksus.dll?Detail&itemSeq=243085164&uq=636456618668326452

Not only would it be thinner, but maybe (?) I could also shave a few millimeters off the PCB diameter .

So, yeah, I'm definitely open to improving the design.

[Nca78]

Hello @NeverDie, the Molex connector was used to replace the I2C connector that you have used, not the IDC one.
Good link you have found for the SMD version, didn't notice the one I found was through holes, SMD version is much better I agree.
That 2.75$ thing on Digikey is way too expensive, I would go for the box version.

[Nca78]

@NeverDie said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

Also, since the back of it is almost entirely ground plane anyway, it seems ripe for using a smaller profile CR2032 battery holder, such as: https://www.digikey.com/scripts/DkSearch/dksus.dll?Detail&itemSeq=243085164&uq=636456618668326452

Not only would it be thinner, but maybe (?) I could also shave a few millimeters off the PCB diameter .

So, yeah, I'm definitely open to improving the design.

Your link is broken, looks like a search result and not a product page ;)

[NeverDie]

@Nca78 said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

Your link is broken, looks like a search result and not a product page

Thanks for letting me know. Not sure what's going wrong. When I click on the link, it takes me right there.

Hmmmmm... The manufacturer's part number is "BK-913-TR". Try entering that into the search field on digikey. It's the one for $0.38.

[NeverDie]

I've just now uploaded Version 3, which fixes an overlap issue in Version 2 between the 10-pin connector and the optional Si7021/BME280. AFAIK, everything should work now.

[NeverDie]

@Nca78 said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

Then there's the DRV5032 from TI that had the lowest power consumption a few month ago when I bought it, it's 0.5$ on Arrow and needs only 0.54uA in the FB (5Hz) version
https://www.arrow.com/en/products/drv5032fbdbzr/texas-instruments

Thanks for the links. I think I'll first try putting the Version 3 TH sensor into the deadbolt cavity and see what kind of range I get with that. It might be seriously impaired, since it will have metal on 2-3 sides. If I'm getting usable signal though at a decent range, then at that point I'll look into adding the DRV5032 to the board.

[NeverDie]

Yesterday I received an CR2477 button cell holder, and it appears that it can easily substitute for the CR2032 in the BOM: the pins seem very much aligned.

https://www.digikey.com/product-detail/en/mpd-memory-protection-devices/BH1000G/BH1000G-ND/140383

Therefore, if you want a battery with roughly 4x the mah and which can also support a higher current drain than a CR2032, it's a good option. :)

[NeverDie]

@Nca78 said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

Your link is broken, looks like a search result and not a product page

Try this: https://www.digikey.com/product-detail/en/mpd-memory-protection-devices/BK-913-TR/BK-913-CT-ND/6200236

[NeverDie]

I just now uploaded some demo source code that will make the node into a proper MySensors temperature node.