element14 Community
element14 Community
    Register Log In
  • Site
  • Search
  • Log In Register
  • About Us
  • Community Hub
    Community Hub
    • What's New on element14
    • Feedback and Support
    • Benefits of Membership
    • Personal Blogs
    • Members Area
    • Achievement Levels
  • Learn
    Learn
    • Ask an Expert
    • eBooks
    • element14 presents
    • Learning Center
    • Tech Spotlight
    • STEM Academy
    • Webinars, Training and Events
    • Learning Groups
  • Technologies
    Technologies
    • 3D Printing
    • FPGA
    • Industrial Automation
    • Internet of Things
    • Power & Energy
    • Sensors
    • Technology Groups
  • Challenges & Projects
    Challenges & Projects
    • Design Challenges
    • element14 presents Projects
    • Project14
    • Arduino Projects
    • Raspberry Pi Projects
    • Project Groups
  • Products
    Products
    • Arduino
    • Avnet Boards Community
    • Dev Tools
    • Manufacturers
    • Multicomp Pro
    • Product Groups
    • Raspberry Pi
    • RoadTests & Reviews
  • Store
    Store
    • Visit Your Store
    • Choose another store...
      • Europe
      •  Austria (German)
      •  Belgium (Dutch, French)
      •  Bulgaria (Bulgarian)
      •  Czech Republic (Czech)
      •  Denmark (Danish)
      •  Estonia (Estonian)
      •  Finland (Finnish)
      •  France (French)
      •  Germany (German)
      •  Hungary (Hungarian)
      •  Ireland
      •  Israel
      •  Italy (Italian)
      •  Latvia (Latvian)
      •  
      •  Lithuania (Lithuanian)
      •  Netherlands (Dutch)
      •  Norway (Norwegian)
      •  Poland (Polish)
      •  Portugal (Portuguese)
      •  Romania (Romanian)
      •  Russia (Russian)
      •  Slovakia (Slovak)
      •  Slovenia (Slovenian)
      •  Spain (Spanish)
      •  Sweden (Swedish)
      •  Switzerland(German, French)
      •  Turkey (Turkish)
      •  United Kingdom
      • Asia Pacific
      •  Australia
      •  China
      •  Hong Kong
      •  India
      •  Korea (Korean)
      •  Malaysia
      •  New Zealand
      •  Philippines
      •  Singapore
      •  Taiwan
      •  Thailand (Thai)
      • Americas
      •  Brazil (Portuguese)
      •  Canada
      •  Mexico (Spanish)
      •  United States
      Can't find the country/region you're looking for? Visit our export site or find a local distributor.
  • Translate
  • Profile
  • Settings
Arduino
  • Products
  • More
Arduino
Arduino Forum Arduino Uno & Melexis IR Temp Sensor(s)
  • Blog
  • Forum
  • Documents
  • Quiz
  • Events
  • Polls
  • Files
  • Members
  • Mentions
  • Sub-Groups
  • Tags
  • More
  • Cancel
  • New
Join Arduino to participate - click to join for free!
Actions
  • Share
  • More
  • Cancel
Forum Thread Details
  • State Not Answered
  • Replies 2 replies
  • Subscribers 391 subscribers
  • Views 255 views
  • Users 0 members are here
Related

Arduino Uno & Melexis IR Temp Sensor(s)

Former Member
Former Member over 10 years ago

Hi all,


I'm new to the forum, I am also rather new to programming and electronics. I have basic electrical circuit/component knowledge from a physics A-level, I have recently read a load of Sparkfun tutorials online, and I have also recently purchased an Arduino Uno as part of 'the Franzis Arduino Tutorial Kit', which I have been using to get into programming.

 

These efforts are all with the aim of gaining enough knowledge to build a DAQ system for a kart, ideally within a month or so. I would like to record various types of data with my system; accelerations, rates of rotation, GPS, steering wheel/pedal positions etc, but I am primarily interested in recording tyre temperatures. Plug and play DAQ options on the market to suit my needs could see total system costs reaching £1000+. Whilst I could afford this, I would rather use this situation as a chance to learn programming - something I've always wanted to do, and perhaps save myself some money along the way.

 

Anyway, my first question is not about programming, it is about hardware. I wonder if anyone has any experience with the Melexis MLX90614 non-contact IR temperature sensor? - https://learn.adafruit.com/using-melexis-mlx90614-non-contact-sensors/wiring-and-test. I have one on order, and doubt I will struggle to wire it up to my Arduino, but this statement from the previous link troubles me: "The MLX90614 has a fixed I2C address, you can only connect one sensor per microcontroller!".

 

I think I understand why this might be the case, but is there any way around this issue, allowing me to wire, say, 4 of these sensors up to my Arduino Uno, or any other microcontroller using I2C? I would of course need each sensor's data to be sent to a storage device, where each sensor's data is kept separated. The only hope I have so far has been found in this university technical report - (credit to the listed authors) http://www.wpi.edu/Pubs/E-project/Available/E-project-042511-130958/unrestricted/2011_FSAE_MQP.pdf. The report claims to be able to use more than one sensor per MC by "daisy chaining" the sensors in line via I2C (see page 34, below Figure 27). Here is where my limited knowledge fails me; could this work? Let's say I daisy-chained my 4 sensors together, in the way described by this report, would this allow data from each of the sensors to be sent through my MC to my data storage device, with each sensor's data kept separate? I am skeptical because; of my ignorance; because of the Adafruit claim above that this is not possible; and because the system designed in this technical report appears to have never been tested to verify functionality.

 

Of course, as you can probably tell, I will have a long way to go to actually make this work, if it is even possible. But I would be grateful of either some reassurance that this can be done, or whether I need to find some different hardware.

 

Many thanks in advance

  • Sign in to reply
  • Cancel

Top Replies

  • shabaz
    shabaz over 10 years ago +2
    Hi Chris, The I2C interface is a standard, you can find the I2C spec here . It explains how the bus works, and how many things can be connected to the same SDA/SCL lines if they can have different addresses…
  • shabaz
    0 shabaz over 10 years ago

    Hi Chris,

    The I2C interface is a standard, you can find the I2C spec here. It explains how the bus works, and how many things can be connected to the same SDA/SCL lines if they can have different addresses.

    If they don't have different addresses (i.e. your scenario, since the MLX device doesn't physically have enough pins for you to hard-code a different address to each device) then there are a couple of options:

    1. Connect each device to a separate pair of wires to the microcontroller

    2. Find some way to switch each device in/out onto the SDA/SCL lines to the microcontroller

     

    For (1), see http://blog.arduino.cc/2010/10/01/softi2cmaster-library-lets-you-add-i2c-to-any-arduino-pin/ for some ideas (I've not inspected the code, but hopefully it can help)

    For (2) see http://www.nxp.com/products/interface_and_connectivity/i2c/i2c_multiplexers_switches/#products

    • Cancel
    • Vote Up +2 Vote Down
    • Sign in to reply
    • Verify Answer
    • Cancel
  • Former Member
    0 Former Member over 10 years ago in reply to shabaz

    Hi Shabaz ( / HarryHausen.. ?!),

     

    Thanks for the reply and info. I read your reply first when you posted it, I've since been splitting my time between work, reading up on I2C, and working on my SD logging. I've now got my logging sorted, so I'm back to working on multiple sensor implementation, I'm sure I'll have a load of follow-up questions on the way.

     

    In the mean time, I was wondering if there is anyone out there who has done a similar thing using I2C, and could share some direct experience.

    • Cancel
    • Vote Up 0 Vote Down
    • Sign in to reply
    • Verify Answer
    • Cancel
element14 Community

element14 is the first online community specifically for engineers. Connect with your peers and get expert answers to your questions.

  • Members
  • Learn
  • Technologies
  • Challenges & Projects
  • Products
  • Store
  • About Us
  • Feedback & Support
  • FAQs
  • Terms of Use
  • Privacy Policy
  • Legal and Copyright Notices
  • Sitemap
  • Cookies

An Avnet Company © 2025 Premier Farnell Limited. All Rights Reserved.

Premier Farnell Ltd, registered in England and Wales (no 00876412), registered office: Farnell House, Forge Lane, Leeds LS12 2NE.

ICP 备案号 10220084.

Follow element14

  • X
  • Facebook
  • linkedin
  • YouTube