Arduino for STM32

It seems like I'm not able to set the register bit with the USART2->CR2 |= 1 << 15; command

the CR2 register looks empty before and after writing the value.

...


Perhaps the USART peripheral clock is not enabled yet where you were trying to do that.

Try setting the CR2 flag after the Serial2 ...

Just be careful about the paths, the path separator in Windows is "\", not "/", so it has to be escaped ("C:\\Users\\...").


I'm the opposite to ag123. I use Windows all the time, and Linux only under protest.

I often have trouble with things that are maybe more at home under Linux, but which ...

Green77 wrote: Fri Aug 19, 2022 5:05 am I did try to paste code here but prog to big.

That is probably a clue that you should try to recreate the problem with something much smaller. Just try to write something to the EEPROM and read it back maybe.

Greetings,

I also suggest that you try the official ST core. I lifted up the code in your first post, and for me it compiles with no complaint using the official core. Code size and ram usage is more than you reported, but should not be an issue on a typical blue pill board. Exact numbers will no ...

@ag123
Blue pill (as most other boards) has 3.3V LDO, so supplying it with 5V from boost converter isn't a problem.

But supplying 3.3V LDO with Li-ion/Li-po battery isn't a good idea. LDOs have a voltage drop of 0.4-1V and Li-ion batteries work in 3-4.2V range, so you won't get stable 3.3V.


I ...

I was thinking about this some more, wondering what calculations that library could be doing that cause you concern. From what I can see, it does various integer calculations, some of which involve uint64_t variables (nothing that looks too heavy to me).

I was wondering what benchmarks might have ...

So results are:Independent of 100k or 400k fpr I2C the execution time stais at 4,4 ms, per transfer of the new data to si5351
...


I still think you are “barking up the wrong tree” here.

Do you have some way to check that the I2C clock frequency actually changed according to what you tried to ...

ad 2: void setup()
{ Wire.begin();
Wire.setClock(400000);
...


How does the timing you measure change if you use a different I2C clock? Say:

Wire.setClock(100000);

The answer to that could let you work out how much of the time is just down loading the required values into the SI5351.

If ...

fpiSTM wrote: Mon May 30, 2022 11:43 am You can try to cast them as uint.

Both getEpochTime() and inReference are uint32_t, so what is that statement trying to achieve?

Maybe forget using abs???

Thanks for your response.



Note: an alternative solution would be to call setPreloadEnable(false); in order to disable the preload feature (the buffer)



I tried inserting that just before the call to setOverflow() and I can see that it turns off ARPE in CR1, so that the change to ARR takes ...