Clock tree problem with Nucleo-L432KC when using D7 and D8 as additional GPIOs

Keil Studio
1

Hi all, I am working on a project using Nucleo-L432KC.

Since I need all the available IOs, I modified the jumpers on the Nucleo in order to disconnect D7 and D8 from the 32kHz crystal and to have them connected to PC_14 and PC_15 instead

It was initially not working, then I discovered I need to disable LSE in order to have D7 and D8 operating:
__HAL_RCC_LSE_CONFIG(RCC_LSE_OFF);

Now the problem is that the pins are actually working (BTW, D8 seems to be input-only), but often the board does not start-up, especially after flashing it.

Pressing the reset pushbutton a few times, makes it working.
I suspect the MCU cannot properly start-up without the 32kHz crystal connected…

Is there a place where to configure the clock tree to start-up with internal RC/HSI and switching to HSE crystal?

Thank you!
Walter

2

Hello,

this is not related to KeilStidio forum section.

From my point of view Mbed try to start LSE where is set a timeout around 5s, so you need to disable dependencies on disconnected LSE like a LowPowerTicker.
Try to do that via mbed_app.json with content below.

{
    "target_overrides": {
        "*": {
            "target.device_has_remove": ["LPTICKER"],
            "target.lse_available": 0
        }
    }
}

BR, Jan

3

Hi Jan,

thank you for the help!
Unfortunately, your suggestion seems to have no effect…

BR,
Walter

4

Ok, try updated settings from above.

BR, Jan

5

Mhmmm… As per your suggestion, here is my Mbed_app.json:

{
“requires”: [“bare-metal”],

"target_overrides": {
    "*": {
        "target.device_has_remove": ["LPTICKER"]",
        "target.lse_available": 0
    }
}

}

I get this error:

Build started
Using toolchain ARMC6 profile {‘ENV’: {‘ARMLMD_LICENSE_FILE’: ‘8224@10.100.166.33:8224@10.100.120.118’}, ‘PATHS’: {‘ARMC6_PATH’: ‘/opt/ARMCompiler6.15.13/bin/’, ‘ARM_PATH’: ‘/opt/armcc5_06_u6/’}, ‘common’: [‘-c’, ‘–gnu’, ‘-O3’, ‘-Otime’, ‘–split_sections’, ‘–apcs=interwork’], ‘cxx’: [‘–cpp’, ‘–no_rtti’], ‘COMPILE_C_AS_CPP’: False, ‘NEW_SCAN_RESOURCES’: True}
scan /tmp/chroots/ch-bab3bbbc-4634-47cc-857f-b5b7d7f908ae/src
scan /tmp/chroots/ch-bab3bbbc-4634-47cc-857f-b5b7d7f908ae/extras/mbed-os.lib
Could not parse mbed app configuration from /tmp/chroots/ch-bab3bbbc-4634-47cc-857f-b5b7d7f908ae/src/mbed_app.json
Internal error.
Build failed

BR, Walter

6

the last double quote before comma is my misstakate from copy & paste

BR, Jan

7

It works! Thank you so much!

BR, Walter

8

You’re welcome and good luck with your project.

BR, Jan