Pekka Ahmavuo

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11 years, 4 months ago.

What's wrong with PWM out?

I was going to port the EPD library on Nucleo F030R8 when I encountered problems with PWM output. My program didn't work but instead printed "pinmap not found for peripheral" on the terminal and halted. Then I tried the Nucleo_pwm example program:

#include "mbed.h"

PwmOut mypwm(PWM_OUT);
//PwmOut mypwm(PB_3);
DigitalOut myled(LED1);

int main() {
    mypwm.period_ms(10);
    mypwm.pulsewidth_ms(1);
    printf("pwm set to %.2f %%\n", mypwm.read() * 100);
    while(1) {
        myled = !myled;
        wait(1);
    }
}

and got the excactly same result.

The Nucleo F030R8 documentation on mbed.org lists the PWM_OUT pin and I can find it from also from PinNames.h.

Question relating to:

Last updated: 30 Mar 2019
Affordable and flexible platform to ease prototyping using a STM32F030R8T6 microcontroller.

I tried PC_7 instread of PWM_OUT. The code worked and I was able to measure 100Hz from the pin.

posted by Pekka Ahmavuo 06 Apr 2014

2 Answers

bco stm
11 years, 4 months ago.

Hello,

The list of the pwm outputs are in the pwmout_api.c file. Today only PA_7, PC_7 and PB_6 pins can output a pwm signal. More pins will be added. Concerning the PWM_OUT label defined in the pinnames.h file, it is an error. We will change it. Thanks for having notice that. Regards.

Accepted Answer
Abraham Howell
11 years, 4 months ago.

Any idea as to when there will be support for PB_10 & PB_4?

Hello, We are working on it. It should come soon on GitHub (end of the week). But I don't know when it will be available on mbed.org. Regards.

posted by bco stm 14 Apr 2014