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nRF52840 startup time

jeppe86

Hi,

I have loaded a simple application on my nRF52840 that just activates a GPIO as soon as it reaches the main loop.

The SoC is powered externally according to the chapter "8.3.5 nRF52840 SoC direct supply" in nRF52840_DK_User_Guide_20201203.pdf.

When I measure the time between power on and GPIO high, I get around 70 ms:



Is there any way to decrease this time? I would like the nRF52840 to start in less than 10 ms.

Parents
  • 0

    Hi

    Can you provide some more information on the following:

    • Confirm that you power the board with ~3.3V (seems like it from your screen shot).
    • What SDK are you using here? The nRFConnect SDK will use a bit more time than the nRF5 SDK before it reaches main I think. What sample project is your project based on?
    • Can you also confirm that this if from system OFF until it sets the GPIO high or if it is from some idle mode?

    Best regards,

    Simon

Reply
  • 0

    Hi

    Can you provide some more information on the following:

    • Confirm that you power the board with ~3.3V (seems like it from your screen shot).
    • What SDK are you using here? The nRFConnect SDK will use a bit more time than the nRF5 SDK before it reaches main I think. What sample project is your project based on?
    • Can you also confirm that this if from system OFF until it sets the GPIO high or if it is from some idle mode?

    Best regards,

    Simon

Children
  • 0 in reply to Simonr

    Hi Simon,

    Thanks for your quick response. Here is the answers to your questions:

    • Yes, the board ist powered with 3.3V from a power supply. I'm connecting to the "External supply" on the board, marked P21 in the User Guide.
    • I'm using nRF5_SDK_17.1.0_ddde560. My project is based on the example project "examples\peripheral\blinky\pca10056\blank\ses".
    • Yes, this is from system off. Then I'm measuring the time from supply voltage on until GPIO high. 

    Looking forward to hear from you again!

    Best regards,

    Jesper

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