Arduino for STM32

I lifted up the first code you posted (that uses input capture) and tried it on 72MHz F103. I could not get it to work anywhere near 100kHz. At 20kHz it was producing output, but looking like this:

Frequency = 0.0000 Dutycycle = 0.0000

I then changed it to produce the pwm output on pin PA1 ...

I lifted up you code (which would have been easier if you had made proper use of code tags) and tried to compile it using the "official" STM32DUINO core, and yes, there are several references to AVR registers like SPDR that will need attention, and also definition of an ISR routine.

However, I see ...

in setup() add

timer = millis();


you forgot to initialize the variable. And use \[code\] blocks to enclose the code in posts here, that makes it much more readable.
(global) variables that are uninitialised takes an undefined value, not necessary 0 (zero). imagine that it is 0xffffff, then ...

Not having all your hardware, I can’t lift up your whole program and try it. However I can pretend that I have a MAX6675 attached, and when I include this in the loop()

if ((millis()-timer ) >= 500)
{
temp1 = thermocouple.readCelsius();
Serial.println(temp1);
timer = millis();
}

delay(1000 ...

When using classic milis processing
if ((millis()-timer ) >= 500)
{
temp1 = thermocouple.readCelsius();
Serial.println(thermocouple.readCelsius());
timer = millis();
}


Maybe you need to explain more as to what the problem actually is. Does the code as you showed work OK, but stops ...

With less than 500nA through the resistors, have you checked the input leakage current specifications?

This is the basic code:-
...

I checked the PWM pins according to the following pin diagram:-
https://how2electronics.com/wp-content/uploads/2019/02/STM32-Pin-Details.jpg


Your link also does not work for me, so I'm not sure what you were working from.

From what you said before, I got the ...

All the meters I have give a sort-of reasonable reading for DC volts on a PWM pin without any filtering. Some meters may be able to measure the frequency, and even duty cycle too. But in any event, there must be some explanation why different pins show different results.

In STM32DUINO, analogWrite ...

Well the first thing that confused me was the whole channel thing (cause there are no "channel" in atmega328 world)
Now I'm starting to think about a channel, and the starting point is that all the frequencies should be "related" or "not too different" to share the same timer... I'll have to read ...

I've 2 digital signals to read/measure:
A: car tachometer data (typically 2pulses/Revolution in 4 cylinder engines)
B: car speedometer data (lets say 1000pulses/KM)
Both of them are not strictly releated each other...
I want the average cpu cycles lenght of each pulses, to calculate its freqs ...