ADT7410: Noise in values?

When I connected the sensor to my microcontroller, my temperature values seem off. I am using a digital thermometer that has +- 2 degrees farenheit to compare values and it seems like the sensor is off by +2 degrees celsius when I get its hex data and convert it. What could be a culprit?

  • 0
    •  Analog Employees 
    on Jan 30, 2018 4:45 AM

    Hi,

    Can I see some schematics of your application as well as the register contents? Do I understand you are using a thermometer with +/-2 degrees Fahrenheit accuracy as reference? In what environment are you testing? Do you have a table of what your reference is reading vs that of the ADT7410?

    Regards,

    Karen

  • All the registers are at default.

    This is the thermometer used to compare values: Amazon.com: Ambient Weather WS-2063-W Indoor Temperature & Humidity Monitor with Backlight: Home & Kitchen 

    Sensor Hex ADC(dec) Sensor C Thermometer C Thermometer F Time PM
    0x0156 342 21.375 19.9(Orig) 67.82 10:16
    0x0156 342 21.375 20.3(Orig) 68.54 10:18
    0x0155 341 21.3125 20.667 69.2 (Orig) 10:21
    0x0155 341 21.3125 21.3889 70.5 (Orig) 10:22
    0x0155 341 21.3125 21.5 (Orig) 70.7 10:23
    0x0155 341 21.3125 20.6 (Orig) 69.08 10:41
    0x0155 341 21.3125 20.5 (Orig) 68.9 10:42
    0x0155 341 21.3125 20.4 (Orig) 68.72 10:45
    0x0154 340 21.25 20.3 (Orig) 68.54 10:47
    Rubbing fingers for 10 Seconds and applying onto thermometer probe and sensor for 10 seconds
    0x019c 412 25.75 26.8


    The environment is within my room that is relatively cold as I don't have a heater on in Houston. It seems like my thermometer was slowly stabilizing to around 20 degrees celsius, while the sensor isn't really budging.

  • 0
    •  Analog Employees 
    on Feb 13, 2018 4:03 PM

    Hi,

    Do you know the accuracy of the thermometer you used? I don't see it but typically a reference should be more accurate than the DUT. You are also testing in a room so there the temperature is constantly changing. We do tests in temperature controlled environments. What you have in the table there from the ADT7410 looks about right, it shows data from sensor taken 30mins apart are within 0.125degC of each other.

    Regards,

    Karen

  • 0
    •  Analog Employees 
    on Aug 2, 2018 4:01 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin