Teensy + thermocouple + LED indicators

Discussion in 'Embedded Systems and Microcontrollers' started by debigg, Jul 8, 2012.

  1. debigg

    Thread Starter New Member

    Jul 8, 2012
    2
    0
    Hey all, I am planning to embark on a new project and would like some pre-project suggestions/help.

    I am planning on creating a temperature controller that monitors the engine oil on my motorbike. I will have a thermocouple like this one (http://www.amazon.co.uk/Thread-Type-Thermocouple-Temperature-Sensor/dp/B0076UIYAA) reading the temperature of the oil. As output I just want to install 3 leds on my dash depending on the temperature of oil. Yellow for cold temps (don't put excessive load/revving the engine), green for when it's in its optimum temperature and red when it's running hot.

    Is this something that can be done with the teensy?? I have some experience in C language (have had it for 2 semesters at uni), but never programmed a microcontroller with it, so would need some pointers on to best go on about it.

    mainly, how do I connect the thermocouple to the teensy and how can I interpret the voltage readings from the thermocouple into temperatures for the teensy? (so that I can tell it for example to keep the yellow led on while temperature is below say 50C)?

    Thanks for any input/help! :)
     
  2. mlog

    Member

    Feb 11, 2012
    276
    36
    What is the temperature range of the oil?
     
  3. BMorse

    Senior Member

    Sep 26, 2009
    2,675
    234
    Look into getting a thermocouple to digital converter IC such as the MAX31855 from Maxim IC..... since that is a K type thermocouple you will need the MAX31855KASA, these IC's are easy to use and don't require any other components, but you will need to be able to provide it 3.3 volts to operate...... and can easily interface to any microcontroller capable of SPI....

    also check out Sparkfun, they have breakout boards for some older model thermocouple to digital conveter IC's, they may have one for the MAX31855.....


    and here is some example using a Teensy with a thermistor to read temperature and change an RGB LED color according to temperature.....https://github.com/roggenkamps/teensy-thermoled#readme
     
    Last edited: Jul 8, 2012
  4. MrChips

    Moderator

    Oct 2, 2009
    12,420
    3,355
    Can be done but I would prefer to use a thermistor instead of a thermocouple.
    You can get this working with a low cost 8-pin MCU and the entire circuit board would be the size of a dime.
     
  5. debigg

    Thread Starter New Member

    Jul 8, 2012
    2
    0
    Ok so if I understand you correctly, this would be much easier with a thermistor? I have now found one that reads in a good temperature range (-50 to +200 C). and BMorse thank you very much for the link! It will take me a bit to dissect the code, but I think I may be able to understand it enough to achieve my goal (as well as the project here http://www.pjrc.com/teensy/tutorial4.html). I am now quite busy with uni but I will order the parts sometime later and start experimenting. thanks a lot! If I have further questions once I actually get the material I shall ask you pros for some more tips! Thanks!
     
  6. BMorse

    Senior Member

    Sep 26, 2009
    2,675
    234

    If you are gonna do the thermistor project with the teensy++, they have the components available (thermistor, LED, resistors, etc.) for the project I linked to for $5.00.....
     
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