Reduce leakage via UART port of Itsybitsy nRF52840 Express

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peterhsi75
 
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Reduce leakage via UART port of Itsybitsy nRF52840 Express

Post by peterhsi75 »

I connected a sensor to Itsybitsy nRF52840 express via UART port (D0 &D1). In order to reduce power consumption, I turn off power to sensor device when I do not need to access sensor data. I noticed that even if the sensor is turn off, the Tx pin (D1) still drains about 4-5 mA current. If I physically disconnect the Tx pin, the current drain stops. Do you know if there is a way to program the D1 pin into a high impedance mode when it is not used for UART communication?

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mikeysklar
 
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Re: Reduce leakage via UART port of Itsybitsy nRF52840 Expre

Post by mikeysklar »

I see the struggle is real here. There is a discussion not he Nordic forum around nRF52 UART power consumption. They are focused on Easy_DMA / UARTE / HFXE being enabled. Things that are probably all below the covers of the Arduino library you are using for serial communication (if that is what you are using).

https://devzone.nordicsemi.com/f/nordic ... onsumption

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peterhsi75
 
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Re: Reduce leakage via UART port of Itsybitsy nRF52840 Expre

Post by peterhsi75 »

Thank you for your good suggestions. I discovered that by using the standard Arduino serial function Serial.end(), I can turned off the serial port and reduce significantly the leakage current via Rx pin of nRF52840. For now, this is good enough for me.

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