Arduino for STM32

FWIW AN3969 states
For low-cost purposes, external EEPROM can be replaced using one of the following
features of STM32F40x/STM32F41x:
●On-chip 4 Kbytes backup SRAM
●On-chip Flash, with specific software algorithm
The STM32F40x/STM32F41x features 4 Kbytes backup SRAM that can be powered from
the ...

@ag123
The problem I have with millis is that they require constant checking. So if I am using 4 things that require delays I these will get checked millions of times before they actually timeout. The other issue is that nothing is done until the check for millis is made, so its impossible to ...

Many Thanks for all the replies and ingenious suggestions.
I had tried changing the prescaler as suggested, but I must have mucked it up.
With The prescaler set to 0xffff, the maximum delay for a 32bit is 1864 hours :o . In my tests for seconds the setOverflow count must be set to n*640. So even ...

I'm struggling a bit with the timers on the STM32f4011. Max time for Tim2 (32 bit) seems to be between 30-60 seconds.
I would like to use the output of one timer as the clock source for several others, like an additional prescaler. I'd prefer to do it this way as it will have minimum impact on ...

@ozcar
Thankyou for that, it now works perfectly .
I had spent some time trying to figure it out, but the timers on the STM32F's are a bit complex for me. I've never come across the "refresh()" procedure?? command before, but it works a treat.

Many Thanks

Best Regards

picclock

Simple timer setup is resulting in an ISR call before time period elapsed. Timer is instantiated, pause(d), setOverflow value written, Interrupt attached, and resumed. The ISR is called immediately (1 second delay shows LED illuminated before ISR turns it off).

Not sure how to proceed. Either the ...

@ GonzoG
Thank You so much. I have spent hours trying to figure this out, getting nowhere.
Cunningly shortening the links so that they appear identical in the posts didn't help either .

Many Thanks for your assistance !!

Best Regards

picclock

@GonzoG
The source code I am using is the official example per the link I quoted in my post.
Arduino Version is 1.8.15

If Board is selected as Blackpill : STM32F401CCU6
Error: 'TIM_TypeDef' does not name a type TIM_TypeDef* _timer;
or
If Board selected as Generic STM32F series, then Generic ...

Hi
I'm trying to implement a timer software interrupt. I've tried using the example from :
https://github.com/stm32duino/STM32Examples/blob/824017c21d555001db1ce047d97b562c1b7b6a9c/examples/Peripherals/HardwareTimer/Timebase_callback/Timebase_callback.ino
But this fails with:
STM32TimerInterrupt.h ...

OK I think I figured it. I wrote a program to clear and read back the BU Ram contents and found that Location 1 holds some data from the RTC. Not sure why 1?, unable to locate declaration. I was using location 0 as a checksum for the BU values, which would seem more logical. Reprogramming the chip ...