pysense: lots of invalid temp/hum values



  • Hi,

    I am running the following code on a pysense board (with a LoPy):

    from pysense import Pysense
    from SI7006A20 import SI7006A20
    import time
    import pycom

    pycom.heartbeat(False)
    py = Pysense()
    tempHum = SI7006A20(py)

    for i in range(1, 100):
    print("{}/{}".format(tempHum.temp(), tempHum.humidity()))
    time.sleep(60)

    Below is the output. It seems that most of the values are invalid. Is there any issue with my code or any known issue with the board ?

    35.33643/48.2554
    35.30425/174.0031
    5181.098/2693.725
    35.34715/16.50949
    5181.088/48.24777
    35.2828/2756.156
    5181.077/48.27829
    35.27207/47.85104
    35.27207/2662.483
    1260.164/174.0183
    5181.152/2662.49
    5181.152/2662.49
    5181.077/670.1731
    1260.186/47.98837
    1260.164/47.76712
    5181.035/2662.445

    Thanks !



  • Testing pysense with LoPy 1.7.9.b3 and pysense 1.1.0. No invalid values, the only issue found temperature returned by SI7006A20 and MPL3005A2 has 1.1 Celsius difference. Do not know which one is correct, need a measurement with another sensor.



  • @bucknall Thank you !!! Just let me know when is ready ...i'm pretty sure a lot of people will apreciate mbus library :)


  • administrators

    @syncope Unfortunately not yet, we're still to implement the internal temperature sensor from Espressif so are waiting to implement that code before releasing a library for the offset!

    Thanks for your patience,

    Alex


  • administrators

    @chumelnicu This is on the roadmap but unfortunately I can't give you an estimate of when it will arrive as we have a number of important firmware features/changes that are taking priority.

    Thanks for your patience!



  • @bucknall said in pysense: lots of invalid temp/hum values:

    This is expected as the temp sensor on the pysense is picking up the temperature of lopy as well. We're working on using the LoPy's internal temp sensor to use as an offset for pysense to give you the real world external temperature (One of the issues with having such a small PCB + package!).

    do you have any news about the offset?



  • @bucknall Hi . Any news about micropthyton mbus lib?

    Thank you!


  • administrators

    Hi @mbriarg,

    What are you referring to? Are you asking about the internal temperature sensor and offset that I mentioned below?



  • @bucknall Hi Alex.Do you have any librery scheduled?
    Just to know if it's matter of weeks or months.



  • @thomas, @bucknall
    Thanks Thomas for checking thoroughly, thanks Bucknall for explaining the cause.

    I managed reduce the offset to < 1 °C by just putting my WiPy on Break-away headers like this one.

    The distance is makes clearly a difference. I did the test outdoor, without housing or enclosure, and compared to my simple outdoor thermometer. If you need exact values you certainly should elaborate more, but for my simple need +- 1° is good enough.



  • @livius
    Thank you for the hint.
    In fact we work with pymodbus, or I should say we use it. I'm not very deep in Modbus and new to Micropython, this is why I currently do not want to go into it deeper. But there are quite a few devices that talk modbus.



  • Ok, thanks @bucknall for the feedback.


  • administrators

    Hi @thomas,

    This is expected as the temp sensor on the pysense is picking up the temperature of lopy as well. We're working on using the LoPy's internal temp sensor to use as an offset for pysense to give you the real world external temperature (One of the issues with having such a small PCB + package!).

    This is in the works and should be arriving soon!



  • Hi @bucknall,

    I've just tested and it's also much better: no more errors so far. Only thing is a ~7° offset with the actual temperature. Any idea ?

    Thanks anyway for the quick changes, great products, great team !

    Thomas



  • @albert_c
    As start point - here is modbus python(not micro python) lib
    https://github.com/riptideio/pymodbus/tree/master/pymodbus

    Maybe this can help somehow


  • administrators

    @albert_c That's great to hear! We're pleased you're enjoying using our devices! :)

    We have a MicroPython Modbus library on the roadmap for internal development; many people in the community have been requesting this library!



  • @bucknall Currently I'm evaluating my first WiPy's / PySenses around my house and garden. I am a Geologist in Germany and work in a small company focused on environmental measurements. We always check promising new products. The PyCom product family seems like a dream come true. Easy to use, cheap, if it now turns out to be also reliable we will certainly use Pycoms for our business. I wish you success!

    Btw: a great thing to have would be a MicroPython Modbus library (in case you have spare time and dont know what to do with it :-) ).


  • administrators

    @albert_c Fantastic! Excited to hear about what you're working on!



  • I did an overnight test: no errors. Works perfectly!
    Thanks a lot for the quick fix.


  • administrators

    Hi @albert_c,

    I've made some changes to the micropython libraries which should increase stability. Could you try them again from https://github.com/pycom/pycom-libraries/tree/master/pysense and let me know if you're still having the same issues?

    Thanks!


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