'STM32F103C8T6' not work PWM Function.

[myksj1105]

'STM32F103C8T6' not work PWM Function.




hello. Nice to meet you. If you look at the picture, it is marked 'PWM' in 'PB_4'.
I tried driving it, but the PWM doesn't work. What's the reason?

Code: Select all

#define BACKLIGHT_LED   PB4
void setup(){
  pinMode(BACKLIGHT_LED, PWM); 
  analogWrite(BACKLIGHT_LED, 255);
}

[GonzoG]

There is no such thing as PWM mode for pins.
You can set pin in INPUT or OUTPUT (with pull-up or pull-down also) mode.
For analogWrite you don't need to set pin mode, as analogWrite does it.

How do you check if PWM works ??

[myksj1105]

Code: Select all

#define BACKLIGHT_LED   PB4
void setup(){
  pinMode(BACKLIGHT_LED, OUTPUT); 
  analogWrite(BACKLIGHT_LED, 255);
}

@GonzoG

Thank you for leaving an answer. Even if you proceed with the source code as follows, it does not solve the problem.

The PWM is connecting to the LED to test its brightness. As far as I know, Arduino's PWM range is 0 to 255.
Extreme values of 0 and 255 do not produce the desired results.

[GonzoG]

@myksj1105
What do you mean by "desired results".
At 0 it's off, at 255, it's on.

[myksj1105]

@GonzoG

Code: Select all

const byte PWM_PIN[20] = {
  PA1, PA2, PA3,
  PA6, PA7, PB0, PB1, PB10, PB11,
  PB5, PB4, PB3, PA15, PA11, PA10, PA9, PA8, PB15, PB14, PB13,
};
#define LED   PC13

void setup(){
  
  //------------------------------------------------------------------------//
  Serial.begin(115200);
  for (uint8_t i = 0; i < 20; i++) { pinMode(PWM_PIN[i],OUTPUT);  }    
  pinMode(LED, OUTPUT);   
  delay(100);
  //------------------------------------------------------------------------//

  //------------------------------------------------------------------------//
  digitalWrite(LED,LOW);
  for (uint8_t i = 0; i < 20; i++) {  analogWrite(PWM_PIN[i], 150);  }  
  delay(1000); 
  //------------------------------------------------------------------------//

  //------------------------------------------------------------------------//
  Serial.println(" SETUP OK!"); 
  //------------------------------------------------------------------------//
  
}

Only 10 out of 20 'PWM PIN' works.
What's the reason?
I wonder. I can't understand.

[fpiSTM]

I can't help as I do not use this core: https://github.com/rogerclarkmelbourne/Arduino_STM32
I maintain the STM32 core.
Maybe your chip is a fake which could explain your issues.

[GonzoG]

@myksj1105
If you use Roger's/Steve's core then with most hardware setup you are limited to standard setup.
With STM32 core all pins connected to timers work in PWM mode.

[myksj1105]

@GonzoG



It seems you are right.
It seems to be correct that it depends on the core.

[trimarco232]

STM32C8T6 has only 3 timers with each 4 capture compare channels , so you can only get 12 pwm outputs a time

[dannyf]

3 general purpose timer (each with 4 channels) + 1 advanced timer (with 4 channels + 3 compl. channels).