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HDC1080: Reading data repeatedly

na na78
Guru 16770 points
Part Number: HDC1080

We want to verify if the reading data is correct or not for increasing reliability of data communication.

The acquisition of both temperature and humidity is assumed.

Our considaration is as following.


1. Is the sequence correct? (Of course, the setting data to register could be optional)
2. Could we repeat reading data from the register without triggering next measurement?
The purpose is the comparison of the reading data.

BestRegards

  • 0
    TI__Expert 5695 points
    Our Applications expert in Humidity will contact you very soon.
  • 0 in reply to Jose Arteaga4
    Guru 16770 points
    Hi Jose

    I appreciate your cooperation.

    I'm looking forward to hearing from you.

    BestRegards
  • 0 in reply to na na78
    TI__Expert 5145 points
    Hi,
    your sequence is correct, but if you want to read Temperature and Humidity together, you have to wait at least 6.50msec (typ. conversion time for humidity value) + 6.35msec (typ. conversion time for temperature value) = 12.85msec typ. We suggest to wait 15/20msec in order to take in account of any spread from device to device.
    Regarding the repeating reading, it is mandatory to trigger the new measurement every loop, and wait 15/20 msec for the conversion time.
    Please let me know if this reply to your questions.
    Best regards,
    Carmine
  • 0 in reply to Carmine Iascone
    Guru 16770 points

    Hi Carmine

    Thank you for your reply.
    >you have to wait at least 6.50msec (typ. conversion time for humidity value) + 6.35msec (typ. conversion time for temperature value) = 12.85msec typ.

    Sorry, I forgot to include temp conversion time. Thank you for pointing out.



    Maybe, my question was unclear.

    I just want to confirm if we can read the same output data repeatedly.  So we don't need to do new measurement.

    Do you mean it is impossible to execute the reading humidity and temperature data without trigger command?

    In otherwords, is it impossible to repeat the command shown in Figure 14 (Read humidity and temperature measurement)?

    BestRegards

  • 0 in reply to na na78
    TI__Expert 5145 points

    Hi,

    Yes, it is possible to continue to read the output data repeatedly, at the end of the conversion time, but you will read always the same last data.

    In order to updated the output register, you need to re-trigger the measurements and wait the conversion time. It is also possible to read continuously the output registers during the conversion phase, but the device will return a NACK, in order to indicate that the measurement is not completed and the output data are not reliable.

    Please let me know if this replies to your question.

    Best regards,

    Carmine

  • 0 in reply to Carmine Iascone
    Guru 16770 points
    Hi Carmine

    Thank you for your reply.

    I got it.

    BestRegards
  • 0 in reply to Carmine Iascone
    Expert 1590 points

    Hi Carmine,

    below is process flow chart, but what get data is 0x10,0x00,0xff,0xff. could you provide any advice?

    thanks~

    Regards,

    Driscoll