[SOLVED] RTT can't connect to STM32F407-DISCO1

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  • RTT can't connect to STM32F407-DISCO1

    I'm able to upload and debug, but connecting with a viewer doesn't work.

    Here's the output of the J-Link Commander V7.00. I've also tried 1000 kHz with the same result.


    SEGGER J-Link Commander V7. 0 (Compiled Apr 8 2021 14:31:32)
    DLL version V7.00, compiled Apr 8 2021 14:30:05

    Connecting to J-Link via USB...O.K.
    Firmware: J-Link STLink V2 compiled Aug 12 2019 10:28:03
    Hardware version: V1.00
    S/N: 778399013
    VTref=3.300V

    Type "connect" to establish a target connection, '?' for help
    J-Link>connect
    Please specify device / core. <Default>: STM32F407VG
    Type '?' for selection dialog
    Device>
    Please specify target interface:
    J) JTAG (Default)
    S) SWD
    T) cJTAG
    TIF>S
    Specify target interface speed [kHz]. <Default>: 4000 kHz
    Speed>
    Device "STM32F407VG" selected.

    Connecting to target via SWD
    InitTarget() start
    ERROR: Unknown DEV_ID found: 0x00000411
    Failed to unlock device.
    Can not attach to CPU. Trying connect under reset.
    ERROR: Unknown DEV_ID found: 0x00000411
    Failed to unlock device.
    Connecting to CPU via connect under reset failed.
    InitTarget() end
    InitTarget() start
    ERROR: Unknown DEV_ID found: 0x00000411
    Failed to unlock device.
    Can not attach to CPU. Trying connect under reset.
    ERROR: Unknown DEV_ID found: 0x00000411
    Failed to unlock device.
    Connecting to CPU via connect under reset failed.
    InitTarget() end
    InitTarget() start
    ERROR: Unknown DEV_ID found: 0x00000411
    Failed to unlock device.
    Can not attach to CPU. Trying connect under reset.
    ERROR: Unknown DEV_ID found: 0x00000411
    Failed to unlock device.
    Connecting to CPU via connect under reset failed.
    InitTarget() end
    InitTarget() start
    ERROR: Unknown DEV_ID found: 0x00000411
    Failed to unlock device.
    Can not attach to CPU. Trying connect under reset.
    ERROR: Unknown DEV_ID found: 0x00000411
    Failed to unlock device.
    Connecting to CPU via connect under reset failed.
    InitTarget() end
    Cannot connect to target.

  • [SOLVED] RTT can't connect to STM32F407-DISCO1

    The problem was because the chip was incorrectly identified as STM32F215 / 217.

    Here's identification from STM32CubeProgrammer.



    The chip is on an official STM32 Discovery board, so I suspect it is in fact STM32F407, but it is somehow being misidentified. It works with SEGGER RTT now when treated as STM32F215 / 217.