Arduino for STM32

I am in need of a few bytes of backup domain RAM on an STM32F103C8 Blue Pill project, and did not find any similar discussions on this forum. I am using the RTC with a coin cell battery backup and that works fine. I plan to use the alarm clock functions as well. I cannot find a diagram of which BKR ...

@GonzoG Thanks, that works!

raduc Thanks for your feedback. After searching for a couple days, I found many references to PWM code for Arduino and Blue Pill. One youTube video shows using pwmWrite() function, but STM32 core library doesn't seem to support it: I get 'not declared in this scope'. What I'm trying to do (simple ...

This Clock is using a 320X240 ILI9341 tft lcd connected over SPI. Also the Blupill does have a 32Khz crystal for RTC and a backup CR2032 battery will keep the clock running and the battery backed up RAM with all the settings up and running even when the power is off. A GPS module is used to set the ...

Hi Gonzo, thanks for your assistance. I have made the code change you suggested. After running this update, the LED remains on and 'USB Not Recognized.'
In Arduino I have the settings:
CDC (generic 'Serial' supersede USART)
U(S)ART support: disabled.

The Blue Pill is powered only from the USB port ...

This was due to an error on my part. I had selected 'BluePill F103C6 (32K)' instead of the correct 'BluePill F103C8 (64K).
Thanks to everyone for the helpful replies.

Hi all, I'm new to the forum. I see this thread is a couple years old, but didn't want to open a new one for the same issue. If I should do so, or post elsewhere, please advise and accept my apologies in advance. I have been programming for 40 years but this is a completely new environment, so my ...

I found something interesting. First, the presence of hal_conf_extra.h didn't change anything, whether it compiled or not. The instructions at https://github.com/stm32duino/Arduino_Core_STM32/issues/228 may need some clarification.
The hex file size (for the blink example) compiled with the ...

Thanks for your reply GonzoG, much appreciated

I must be interpreting the documentation on that site incorrectly.
I have this content in hal_conf_extra.h in the sketch folder.

// turn off STM32 HAL library elements that are not needed
#define HAL_ADC_MODULE_DISABLED
#define HAL_I2C_MODULE ...

Thanks GonzoG for your reply.
I turned on verbose compile/link output and see tons of library files being linked in, as you pointed out. I can turn off U(S)ART in the IDE. Excuse my newbie-ness, how does one disable all these unneeded libraries from being included? Are those items installed in ...