[New Variant] Nucleo 32 - STM32F042K6

[battosai30]

Board description (please complete the following information):

• Name: Nucleo 32 - STM32F042K6
• Link to all relevant information:
  • https://www.st.com/en/evaluation-tools/nucleo-f042k6.html#resource

Hi,
USB + CAN in this budget is pretty cool :)
Any plan on integration in this core ?
I'll buy one to try to add it myself but I'm not used with STM32 so ... :)

EDIT : integration started https://github.com/battosai30/Arduino_Core_STM32/tree/master/variants/NUCLEO_F042K6

• All digital I/O working

• All analog I/O working

• All PWM I/O working

• Serial (ST-LINK) working

• Alternative Serial working

• SPI working

• i2c (master & slave) working

• sleep working

[fpistm]

Hi,
it has been added to the [New Variant] request list #722.

[battosai30]

Hi,
I worked on it and it seems basically okay. I succesfully ran a blink, serial communication between PC and board and I connected a RC522 so SPI works. Here the files before I start a PR.

I have some questions :

• Is there any features list to test before starting a PR ?

• in PeripheralPins.c I commented some lines about GPIOs needed for serial communication. But is there any good pratice about that ? Sorry I'm newby with STM32 :) I saw other variants with this kind of modifications, what could be the reasons ?

• I had compilation error because in PinNamesVar.h some pins where not referenced. I look in the datasheet, this pins are not exposed by the LQFP32 package, is this a problem ?

• Still in PinNamesVar.h I commented out PA_15 mentioned as USB_NOE. Is this a problem and what USB_NOE means ?

• Is my clock config okay ?

Regards

[fpistm]

Hi,
I worked on it and it seems basically okay. I succesfully ran a blink, serial communication between PC and board and I connected a RC522 so SPI works. Here the files before I start a PR.

Great. Thanks

I have some questions :

* Is there any features list to test before starting a PR ?

Basically, we test all basic Arduino API:
Serial, SPI, I2C, ADC, PWM

* in PeripheralPins.c I commented some lines about GPIOs needed for serial communication. But is there any good pratice about that ? Sorry I'm newby with STM32 :) I saw other variants with this kind of modifications, what could be the reasons ?

You can kept them. If user disabled the Serial usage then he could access them. In a general way, only the duplicated pins are commented as only the first one found is used. I will try to remove this limitation soo.

* I had compilation error because in PinNamesVar.h some pins where not referenced. I look in the datasheet, this pins are not exposed by the LQFP32 package, is this a problem ?

In that case simply comment them.

* Still in PinNamesVar.h I commented out PA_15 mentioned as USB_NOE. Is this a problem and what USB_NOE means ?

https://community.st.com/s/question/0D50X00009XkaCOSAZ/otg-on-l476-what-is-otgfsnoe
You can comment it without any issue.

* Is my clock config okay ?

It seems fine, anyway I will configure also USB clock at 48 MHz. To do this in CubeMX, enable the USB device support in the connectivity menu.

[battosai30]

Thanks for your quick answer !

• I had compilation error because in PinNamesVar.h some pins where not referenced. I look in the datasheet, this pins are not exposed by the LQFP32 package, is this a problem ?
  In that case simply comment them.

I can't, I specially added them because if I don't, I get the same error as here #907

It seems fine, anyway I will configure also USB clock at 48 MHz. To do this in CubeMX, enable the USB device support in the connectivity menu.

And here comes a little problem : USB and CAN cannot be used at the same time because they share the same pins. As I understand it, CAN doesn't need a clock configuration, so I should active USB and disable CAN in CubeMX so at least USB is ready to use and CAN (I guess) too. Can you confirm that ?

Regards

[fpistm]

OK for the pinname var.
and yes for USB and CAN. I'm only talking about USB clock.

[battosai30]

Just to be sure, you confirm that if I want to use CAN, that won't be an issue if I don't activate it in CubeMX ?

CAN is the "cool" thing for me in this MCU, so after integration in Arduino itself I will try to get CAN working ;)

[fpistm]

Yes this is not dependent.
FYI it seems someone already do a CAN library for this core:
https://github.com/exothink/eXoCAN

Tested only for F103 but I guess it could be a good base for you.

[battosai30]

Thanks !
I found this too :
https://github.com/nopnop2002/Arduino-STM32-CAN
https://github.com/seeers/CAN-Bus-Arduino_Core_STM32

[battosai30]

A simple blink code takes 9196 bytes of memory. I tried disabling HAL components :

#define HAL_ADC_MODULE_DISABLED
#define HAL_I2C_MODULE_DISABLED
#define HAL_RTC_MODULE_DISABLED
#define HAL_SPI_MODULE_DISABLED
#define HAL_TIM_MODULE_DISABLED

Is this normal ?

[fpistm]

by default yes it seems normal. By disabling all HAL module should reduce it.
Where did you define it ? You have to use the build-opt.h for this

[battosai30]

Oh ok I read two quickly the wiki ;)

I had a hal_conf_extra.h file to my sketch and compiled with :

#define HAL_ADC_MODULE_DISABLED #define HAL_I2C_MODULE_DISABLED #define HAL_RTC_MODULE_DISABLED #define HAL_SPI_MODULE_DISABLED

And I got a 9092kB flash size :s Disabling Serial gives 7736kB . Better

I tried with HAL_*_MODULE_DISABLED but got the same size (9196kB) with warnings like :

warning: ISO C++11 requires whitespace after the macro name 9 | #define HAL_*_MODULE_DISABLED | ^~~~

So I guess this directive was not taken account ... And the * is responsible of this (Arduino v1.8.10) as when I erase it warnings disapear.