Connect with us

Salvaged Humidity Sensor

Discussion in 'Sensors and Actuators' started by bigone5500, Sep 8, 2015.

Scroll to continue with content
  1. bigone5500


    Apr 9, 2014
    I salvaged a humidity sensor from an old HP laser printer. The number on it is RHI-110D-CA. It has 4 wires. Pins 1 through 4 are Vin, SDA, GND, and SCL respectively. The chip is what I think I have found to be an equivalent of this.

    The power source is 3 to 5.5vdc so I am sure I can use it with an arduino. However, I am unsure how to do this. Do specific parts need their own libraries to operate? Can they be simply connected and load a generic sketch and library?

    20150907_153929.jpg 20150907_154214-1.jpg
  2. davenn

    davenn Moderator

    Sep 5, 2009
  3. jayanthd


    Jul 4, 2015
    If you post the datasheet of the device RHI-110D-CA then I might be able to provide you a an Arduino code to read humidity.
  4. bigone5500


    Apr 9, 2014
  5. bigone5500


    Apr 9, 2014
    Thanks Dave. I am going to play around with it and see what it will do. I am a bit leary of it being accurate without knowing more about it.
  6. Gavin Groce

    Gavin Groce

    Apr 17, 2017
    Ok this is an old post but I have access to a bunch of these, so here is the data.

    1 power 3v to 5.5v
    2 temp humidity in serial dat a
    3 GND
    4 Serial Clock

    Humidity Hex Table
    10% 064 20% 0c8 30% 12c 40% 190 50%1f4 60% 258 70% 2c 80% 320 90% 384

    Temprature Hex Table
    5c 3c 15c 50 25c 64 35c 78 45c 8c 55c a0

    I am trying to use this wit a raspberry pi and mqtt.

    Hope it helps.
  7. silvestro


    Aug 24, 2017
    Hi Gavin,
    did you make any progress with using the sensor and raspberry?

    I have a few of these and would like to get environmental data using arduino or ESP8266 ...

    Thank you,
  8. bigone5500


    Apr 9, 2014
    I have a new humidity sensor which is different than the original one in this thread. I need to figure out how to use it with arduino. Anyone ever used one of these: HSU-07A. It came from a laser printer. I have a working thermometer and want a humidity readout along with the temp.

    I have read on a datasheet that you should have a 47uF cap and 100k resistor in parallel on the Vout line. Then I read on another forum that someone said to not use them. This board uses a chip with the information: 2903 H193A.

    Last edited: Sep 6, 2017
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day