Arduino for STM32

I got 19MHz wit digitalReadFast and 33MHz with digitalWriteFast, but with typing 1000 lines of code. While loop needs few cycles. @GonzoG PLease give us your code ! (I do not pretend to get the fastest .. just starting to play) Sorry.. copied wrong values. Those were Mops/s, so frequency is half of...

ManX84 wrote: ↑Mon Oct 23, 2023 4:04 pm Need Faster ?

Code: Select all

	// Here use a digitalWriteFast !
	do
	{
		digitalWriteFast(PC_13, 1);
		digitalWriteFast(PC_13, 0);
	} while (1);

F = 7 MHz!

I got 19MHz wit digitalReadFast and 33MHz with digitalWriteFast, but with typing 1000 lines of code.
While loop needs few cycles.

It can be done, but not without using LL or CMSIS and it will need way more flash and RAM then code written in "pure" c/c++.

There are many open source bootloaders that use SD card to flash firmware. You might even find one for your MCU or might need to tweak few lines of code.

Have you tried any DS3231 library ??

So that brings me to two new questions: 1. if using such a voltage divider circuit for multiple PCB's, how do you ensure consistency? Measure the actual resistance values prior to uploading code, and then hardcode the individual resistor values into the Arduino program for each PCB? I.e. calibratio...

1. Are you sure, the input voltage is exactly 3.3V ??
2. Are you sure that those resistors are exactly 4.7M and 2.2M ?

1. If you're using pullups, then with button pressed you get 0, and not pressed you get 1.
2. PC12-PC15 pins cannot source current, but they can sink, so pin provides GND to LED. 0 = on, 1= off

F072C8 has DFU bootloader, so just reset it into bootloader and you can flash it using USB.

Also STM does not provide software USB bootloaders.
You can probably make one using this: https://github.com/Serasidis/STM32_HID_Bootloader

PWM does not control voltage. You cannot use PWM to lower voltage, it only controls time how long power is turned on and off.
Voltage reading will depend on your meter, PWM frequency, board hardware and MCU.

No. .bin extension is for "binary". STM32 MCUs use binary files for firmware upload. You need .bin file if you want to upload firmware to STM32 MCU, unless you have an application that converts HEX file into binary format before uploading it.