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

[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.

[NeverDie]

I just now uploaded the Version 4 files. The new design uses the more compact CR2032 battery holder discussed above. :)

[NeverDie]

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

Also, what about moving the led to the center next to its resistor, it would leave enough space to squeeze in a SOT 23 ultra low power hall sensor and it's 100nF capacitor.

Yes, with the Version 4 design serving as the basis, I think there will be enough room to do this.

I'd also like to add a light sensor of some kind: something that will trigger an interrupt when, say, a refrigerator light goes on or off (for the case where the temperature node is in a refrigertor or freezer). Do you have any particular suggestions for that? A simple photoresistor, or would there be something better (lower current)?

[Nca78]

Low current light sensor with interrupt, you have OPT3001 and MAX44009. MAX44009 has the lowest power but it doesn't have the same availability (not on Arrows for example).
If you're planning to use it from breakout board (as they are boath really tiny) then MAX44009 is the best choice as it's cheaper on AliExpress.

If you want one that you can solder by hand you can check VEML7700, it's cheap, has low power consumption (2uA) if you use a low refresh rate. But it goes only down to 2.5V so you will lose a bit of the capacity of the button cell, and it has no interrupt pin.

[NeverDie]

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

Also, what about moving the led to the center next to its resistor, it would leave enough space to squeeze in a SOT 23 ultra low power hall sensor and it's 100nF capacitor.

Done. I just now uploaded Version 5, which has the TI hall effect sensor.

[NeverDie]

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

MAX44009 has the lowest power but it doesn't have the same availability (not on Arrows for example).
If you're planning to use it from breakout board (as they are boath really tiny) then MAX44009 is the best choice as it's cheaper on AliExpress.

Looks as though if I add just one more header pin, then I can use this board:
https://www.aliexpress.com/item/MAX44009-Ambient-Light-Sensor-Module-with-4P-Pin-Header-Module/32729312303.html?spm=2114.search0204.3.47.XOZuu8&ws_ab_test=searchweb0_0,searchweb201602_4_10152_10065_10151_10344_10068_10130_10345_10324_10342_10547_10325_10343_10546_10340_10341_10548_10545_10541_10562_10084_10083_10307_10178_10060_10155_5680017_10154_10056_10055_10539_10537_10312_10536_10059_10313_10314_10534_10533_100031_10103_10073_10102_10557_10558_10142_10107-10178,searchweb201603_25,ppcSwitch_4_ppcChannel&btsid=ca20f561-ad43-4536-b09f-7856bf41fbb2&algo_expid=0601cfd8-6d07-4336-aefc-c06bc54166ac-2&algo_pvid=0601cfd8-6d07-4336-aefc-c06bc54166ac
That way I could capture the interrupt.