DeepSleep Shield

  • Does anyone know if the deepsleep shield impacts the operation of the LiPo charger on the Expansion Board? i.e. if this is enabled, does it disable the LiPo charger onboard?

  • @ledbelly2142

    I just tested this. I have a LoPy on a 18650 battery (via an expansion board), with a current shunt inline to monitor battery current.

    Control test: Without DeepSleep shield:

    While connected to USB, I observed charging current going into the battery. If I unplug the USB, then the battery discharges: 100mA for active Wifi, 35mA w/o Wifi, and 10mA for disabled WiFi and machine.deepsleep()

    With DeepSleep shield:

    Using the "deepsleep" library with the DeepSleep shield, and connected via USB, I put the device to sleep. The charging current for the battery was unchanged. I then disconnected the USB, and the current draw from the battery dropped below 1mA. I can't measure much lower than that with my setup.


    The DeepSleep board works as expected with batteries.

  • @bradnz
    I don't have a deep sleep shield yet but there really should be no problem, the deepsleep shield (like the LoPy) comes after the power multiplexer while the charger chip is before it

  • Interesting questions, I also would like to know the answer. If you have a Lopy that is plugged into a power source (e.g. via USB power only) and the LoPy is set to deep sleep with deep sleep shield, will an attached 3.7v LiPo battery be charged?

    I don't have a deep sleep shield to test this with yet.

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