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AC_Hacker · 02-25-13, 01:52 PM

I've been searching for a reasonable humidity sensor, and there are quite a few available.

Seems that Honeywell has quite a few, and Sparkfun & Adafruit have them in stock.

It could be useful to be able to measure temperature and humidity with the same sensor (many of the sensors do this), but I have several 1-wire temperature sensors in my parts kit and I trust their performance, so combined sensors is not by itself a deal-maker.

Looking over the specifications, I see that almost all of the humidity sensors require 3.5 volts. There are cheap surface mount voltage regulators available, but it's just more to do.

I do have a combined humidity/temperature sensor (Sensiron SHT-15) see photo below:

This is a full size photo on my computer screen, hold a penny to your screen, see if it works on yours...

But this sensor is really awfully small, and to use it will require micro-surgery and some kind of breakout board. Even though I recall that there is an Arduino library for this chip, it's a bit discouraging, even though I have the part I need.

Sparkfun & Adafruit do have sensors already mounted on breakout boards, so that's a plus right there.

But then I came across this on Ebay...

It's still pretty small, but no microsurgery required. It has a tiny adapter board already attached with the required resistors, etc. and the pin-out is VCC (5V), Ground, and signal. The language was a bit mincing, as though it had been run through a Chinese meat grinder, but I have a suspicion that this is a 1-wire device and that both the temperature and humidity information are available on the center pin. Things will get simpler if that's the case.

So, (...drumroll...), I sent $6.64 to China to see if I'm right... I do realize that this is a big gamble, but I guess I'm just reckless that way.

Best,

-AC

02-25-13, 01:52 PM	#45
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	Searching for humidity sensor... I've been searching for a reasonable humidity sensor, and there are quite a few available. Seems that Honeywell has quite a few, and Sparkfun & Adafruit have them in stock. It could be useful to be able to measure temperature and humidity with the same sensor (many of the sensors do this), but I have several 1-wire temperature sensors in my parts kit and I trust their performance, so combined sensors is not by itself a deal-maker. Looking over the specifications, I see that almost all of the humidity sensors require 3.5 volts. There are cheap surface mount voltage regulators available, but it's just more to do. I do have a combined humidity/temperature sensor (Sensiron SHT-15) see photo below: This is a full size photo on my computer screen, hold a penny to your screen, see if it works on yours... But this sensor is really awfully small, and to use it will require micro-surgery and some kind of breakout board. Even though I recall that there is an Arduino library for this chip, it's a bit discouraging, even though I have the part I need. Sparkfun & Adafruit do have sensors already mounted on breakout boards, so that's a plus right there. But then I came across this on Ebay... It's still pretty small, but no microsurgery required. It has a tiny adapter board already attached with the required resistors, etc. and the pin-out is VCC (5V), Ground, and signal. The language was a bit mincing, as though it had been run through a Chinese meat grinder, but I have a suspicion that this is a 1-wire device and that both the temperature and humidity information are available on the center pin. Things will get simpler if that's the case. So, (...drumroll...), I sent $6.64 to China to see if I'm right... I do realize that this is a big gamble, but I guess I'm just reckless that way. Best, -AC Attached Images __________________ I'm not an HVAC technician. In fact, I'm barely even a hacker...