Sensors. Using a module or standalone components?

Forum 2005-2010 (read only) Hardware Interfacing
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For temperature and humidity reading, in my case. I'm making a terrarium that is monitored and regulated with the Arduino.

  1. What are the pros and cons of both?
  2. What is the job of the IC on a module such as this?
  3. If I go with a module, will it survive in 100% humidity?
    Any other thoughts or tips are welcome too!

I'm still a big newbie, so please try to explain in... simple words :wink:

Thank you in advance!

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What EXACTLY do you mean by "module" and by "stand alone"??

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"What EXACTLY do you mean by "module" and by "stand alone"??"


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They're marketed as sensor modules, so I thought I'd be clear enough.

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They're marketed as sensor modules, so I thought I'd be clear enough

It's really useful that you let us know that right from the outset.

  1. What are the pros and cons of both?

"both" what?
Regulation and monitoring, or temperature and humidity?

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"both" what?

Sensor module vs just a sensor. As in the pictures I liked to.

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We're supposed to be able to tell by looking at photos?

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This is an article about connecting the hs1101
http://gdallaire.net/blog/?p=3
At the end it says: "use smarter sensors and save time."

$12 for two sensors with SPI, analog, and TTL/UART interface is not over-expensive..

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The raw sensors elements need some circuits around them to make them useful in systems like talking to microcontrollers (like Arduino). If you get just the raw sensor element, you will have to provide all that supporting circuit to allow connection to Arduino, etc.

OTOH, if you buy the complete module, they have provided (and presumably tested) all the support circuits and you can connect them to Arduino straightaway.

Thank you for your reply.
What confuses me is that you can connect, for example, a thermistor or photoresistor to an analog In without fancy modules, like this. It makes me wonder that the job of the IC on module really is.

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Thank you very much for your help, now I understand :slight_smile:

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It makes me wonder that the job of the IC on module really is.

Richard has already covered most of what I planned to say. Another possibility is that the sensor has a really low output voltage, or a really high output impedance, so the module designer put an op-amp on the board to make an easier-to-use/more-noise-immune signal.

Or the module might be designed for something like the BASIC Stamp, which isn't very good at A/D conversions or highly precise frequency/pulse width measurements.

You really need to look at the specific cases to determine whether the extra circuitry on a module is useful or necessary.

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It is not so much they hide; it is a PIC on th board (because it costs less than an AVR)..
http://www.sure-electronics.net/download/DC-SS500_Ver1.0_EN.pdf

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A lot will be hidden inside the software anyway....