PySense + FiPy deepsleep high current

  • Hi everybody

    I'm a little bit lost, as deepsleep doesn't look to be working correctly with my setup, as I always get around 5 mA while in deepsleep. The setup is:

    • FiPy (tried versions 1.80 -> 1.20)
    • PySense 0.0.8 (did at least 5 times the update, to make sure its done)
    • Power-Source USB or JST

    I use the following code ...

    # -- put your code here!
    from pysense import Pysense
    from LIS2HH12 import LIS2HH12
    from SI7006A20 import SI7006A20
    from LTR329ALS01 import LTR329ALS01
    from MPL3115A2 import MPL3115A2,ALTITUDE,PRESSURE
    import pycom
    import time
    import machine
    # if not pycom.lte_modem_en_on_boot():
    #     pycom.lte_modem_en_on_boot(True)
    #     machine.reset()
    # if not pycom.wifi_on_boot():
    #     pycom.wifi_on_boot(True)
    #     machine.reset()
    #py = Pytrack()
    py = Pysense()
    # display the reset reason code and the sleep remaining in seconds
    # possible values of wakeup reason are:
    print("Wakeup reason: " + str(py.get_wake_reason()))
    print("Approximate sleep remaining: " + str(py.get_sleep_remaining()) + " sec")
    # enable wakeup source from INT pin
    acc = LIS2HH12()
    # enable activity and also inactivity interrupts, using the default callback handler
    py.setup_int_wake_up(True, True)
    # set the acceleration threshold to 2000mG (2G) and the min duration to 200ms
    acc.enable_activity_interrupt(2000, 200)
    # go to sleep for 5 minutes maximum if no accelerometer interrupt happens
    # Finally go to sleep

    If I use the JST-Connector for powering the pysense (still with 5V) current drops by 0.5mA to something around 4.5mA but its still far away from what I would expect.

    Anybody has a hint for me, what I'm doing wrong or what I might try?

    Thanks in advance!

  • @jcaron well I need the accel, because it's a "wake on shake" use-case. Everything you mentioned is already tested. Of course I tested by powering the device via the JST and not the USB port. Same results. Also I tried exchanging the FiPy by a LoPy4. Also the same. But then I switched the Pysense by another and all of a sudden it worked. Looks like a hardware fault.

    Nevertheless thanks for your suggestions!

  • @sebastian-muesch in my experience accelerometer wake up will use over 300 uA. If you want the lowest possible power draw you need to turn that off.

    Other possible culprits:

    • the LTE chip. It seems to be nightmare to turn it off, especially if there’s no SIM or you haven’t actually used it then turned off.

    • an SD card if you use one

    • you may try adding false as argument to go_to_sleep

    • you will definitely get bad results powering via USB

    Good luck!

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