[SOLVED] flashing comms led on STLink v2 with JLink firmware

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  • [SOLVED] flashing comms led on STLink v2 with JLink firmware

    Hi,

    Recently I "migrated" my STM32F4 Discovery board's ST-Link to a Segger JLink configuration. It works perfectly!
    However, one thing annoys me a bit. When the USB connection is not present, the STLink comms LED ( a bright green one) is flashing continuously at 5Hz. My board is powered through an external 5V supply and frequently USB is not hooked up at all, thus providing me with the flashing LED.
    The flickering green LED is irritating after a while. Is there a way to turn it off (apart prom soldering it off the board) ?

    Ewout Boks
  • Hi Ewout,

    this is "intended" behavior. The ST-Link is now a J-Link, and J-Link blinks with 5Hz if it can not enumerate via USB.
    (As a normal J-Link in only powered when it is used on a PC, so not being able to enumerate means sth. is wrong)

    Maybe it is possible to disconnect the ST-Link from Board power, so that it is only powered if connected to USB?

    Best regards,
    Niklas
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