Hardware switch debouncing vs deep-sleep current



  • In my battery powered device based on L01 I would like to implement several micro-switches - for reset and device control as well.

    I used the same de-bouncing circuit as Pycom used in their OEM baseboard design for RST pin - 20k pull-up resistor and switch with capacitor towards GND in parallel:

    0_1506155761758_reset_pin.png

    I measured quiescent current through pullup resistor using uCurrent tool. It seems to be in sub-uA region.

    Then I used the same circuit connected to Pxx pin (will be used for device control in the code) and the quiescent current seems to be at the same level.

    Should I expect any issues with increase deep-sleep current with this approach?
    Maybe better idea would be to pull Pxx pins to GND and switch towards VDD?



  • @robert-hh
    Thanks for confirmation. With the uCurrent tool I measured current in order of tens of nA but I was not sure if measurement of such small currents makes sense.



  • @danielm The circuit above should not consume any current, if the PIN is set to input and the button is not pressed, besides some leakage. The ep32 data-sheet specifies an input leakage current of max. 0.05µA. The leakage of the capacitor should be almost Zero too. In a real set-up the leakage caused by dirt plus humidity may be higher.


Log in to reply
 

Pycom on Twitter

Looks like your connection to Pycom Forum was lost, please wait while we try to reconnect.