Topic: Peet Bros temprature/humidity sensor alternatives

[pepper]

I was wondering if there were any alternative temp/humidity sensors (other than Peet) that will work with The Ultimeter 2100 ?
Or is everyone using the Peet Bros one?
TIA
Pepper

[DaleReid]

I am using the Peet ones.  I have found them to be very good across a wide range of temperatures and humidities, and never bothered to try to duplicate the circuit or swap out.

Have they become unavailable, or just cost more than you wanted?

[pepper]

Have they become unavailable, or just cost more than you wanted?

Just cost more than I wanted to pay and I enjoy tinkering.
I was interested to see if I could use one of the many temp/humidity sensors on the market. I would be surprised if they were a custom design.

[doubleohwhatever]

Is this the humidity sensor you need to replace?:
https://www.peetbros.com/shop/item.aspx?itemid=83

If so, then it actually does appear to be a custom design. It appears to be a fairly basic design and likely has a low component cost. However, it definitely is not a common I2C or SPI sensor (Sensirion, etc).


Also, based on the pinout (+5, GND, TMP, HUM), I'm going to guess that it's analog output and not something digital (serial, I2C, etc) that could be easily emulated.

Who knows though, the photo on the website is a little too blurry to really say anything for sure.

[DaleReid]

Pepper:  All mine (just a few) are still working, and I hate to fiddle around and ruin one.

If you have one that is not working, can you get the board out, to see if it is like the one DoubleOh posted?  I'm thinking the age of the design is such that the temp and humidity sensors are not integrated on to one chip.

Are both in error?

If you can get it open, are the components covered with conformal (sp?) coating to protect them, except for the humidly sensor?

Can you take a good hi-res image of the humidity sensor?  It may be easy to replace just that to get it working again.

These original units were around for a long time, and may even pre-date I2C and such by a bit.  I know that the early Davis stuff used analog sensors which are no longer available, which in essence turned those stations into wind speed/direction or expensive rain gauges.

[pepper]

Is this the humidity sensor you need to replace?:
https://www.peetbros.com/shop/item.aspx?itemid=83

If so, then it actually does appear to be a custom design. It appears to be a fairly basic design and likely has a low component cost. However, it definitely is not a common I2C or SPI sensor (Sensirion, etc).


Also, based on the pinout (+5, GND, TMP, HUM), I'm going to guess that it's analog output and not something digital (serial, I2C, etc) that could be easily emulated.

I currently only have the temp sensor and was having issues convincing myself to part with $120 to add a humidity sensor, if I could build the same.
Yes, by the looks of the picture it's analog.
But at $49 for the PCB I'm happy with that. I can mount it in an old solar shield from a dead weather station.
That's a very expensive enclosure for that PCB!
Thanks for pointing out the replacement parts section, I didn't notice it. Very handy!

[pepper]

Pepper:  All mine (just a few) are still working, and I hate to fiddle around and ruin one.
 
If you can get it open, are the components covered with conformal (sp?) coating to protect them, except for the humidly sensor?

Can you take a good hi-res image of the humidity sensor?  It may be easy to replace just that to get it working again.

I'm going to order the board, I'll take photos and post.

[doubleohwhatever]

Yeah, at $49 I'd likely have just bought one as well.

If you post some high resolution photos of it we can see what all is going on with the design. The PCB is definitely simple but I just can't make out some of the components. For example, I can't tell if the 8-pin dip component is just an IC or if it's a microcontroller. If it's the latter that complicates things a bit.

Overall, I'm sure it can be replicated if Peet Bros ever stops selling them. However, as long as the board is available for $49, reverse engineering probably isn't worth the hassle.

[DaleReid]

Yes, please let us know what  you find.

When Texas Wx Instruments was still in business, I got a box but no outdoor sensors for it. Rain, Barometer and wind (which was interfaced on that one to an RM Young sensor) were all OK, but the temp/humidity was lacking.  I found their 'pagoda' with the sensor inside was at that time a bit over $350 bucks!  Sticker shock.  I got one at a discount from one of the resellers (Ambient at the time?) for quite a bit less and was actually shipped from TWI.

Even worse was their solar radiation sensor (I'm not knocking them, they had good stuff but need to temper their markups) which was basically a photo-sensor like a transistor) potted in a 1/2 sphere of translucent epoxy that was mounted on the end of a foot long piece of aluminum angle material.  Probably $25 total with the wire, and they were asking over $200 for it.  I talked to one of the techs on the phone and he told me how to take a LiCor sensor for $75 from eBay and wire it on.  I think he was a bit embarrassed over what the company had marked them for sale.

Anyway, I am like you, I won't throw anything away without trying to see if it can be fixed or repaired, and while my abilities have diminished dramatically with hand strength in the last year, still like fiddling.  You still may be able to salvage the old one for a very small investment and a feeling of success.