Arm Mbed OS support forum

Error Status: 0x80FF0100 Code: 256 Module: 255 , cannot initialize pwm

Hi,
I am not able to generate Pwmout with my code. My board is nucleof401re.
I want to generate pulses of a specific frequency, which depends upon the rate entered by the user.
Initial code works fine which includes taking data from the keypad, PWM part doesn’t work.

Code-:

PwmOut clk(D9);
frequency = 212*rate // rate is entered through keypad
unit_vol_time = 60000 / (rate);
 while(value)
        {  
            period = 1/frequency;
            clk.period(period);
            ThisThread::sleep_for(unit_vol_time);
           //delay(unit_vol_time);//millis
            clk.suspend();
             value--;
            if(value==0)
            {
               printf("Job Over\n\r"); 
            }
            
            else
            {
                printf("Value Remaining : %d",value);
                
            }

The output for this code as seen in coolterm shows the following error:

Please help me resolve this issue.
Thanks in advance.
Akanksha

Hello,

for correct code formating in your post please use ``` before and after code section.

I do not try that but you for some reason call clk.suspend();And documentationod of PwmOut - suspend() say

The subsequent function call must be PwmOut::resume for PWM to resume; any other calls prior to resuming are undefined behavior.

So maybe try it without that line or a call resume() method.

BR, Jan

Hi,
I tried to run the code removing Pwm suspend() instruction and also by adding Pwm resume(), but to no avail.
Error code remains the same.

I want to write equivalent STM code for this piece of Arduino code, replacing notone() by suspend().

 tone( 12, frequency );    
    delay(unit_vol_time);//millis
    noTone(12); 

Regards
Akanksha

Ok, then I think the reason of this error is zero value in the period variable. Whitch si result form period = 1/frequency; So try to verify that calculation and correct usage.

You probably need to modify it to something like this

period = (float)1 / (float)frequency;

BR, Jan

I verified the calculations and also modified it but nothing worked. I also tried to replace frequency with a fixed number but that also showed the same error.
It seems there is some problem when a serial terminal is in use.
After searching the web , I found this-
https://os.mbed.com/questions/82584/Error-Status-0x80FF0100-Code-256-Module-/

Regards
Akanksha

It is hard to test your code when is not complete.
In that old question what you mentioned also Ralph Fulchiero confirmed same what I wrote above.

The problem is 0 in the period variable what is passed as parametr to the clk.period() method.

period = 1/frequency; 
clk.period(period);

I modified your code because it is not complete and tried it on MbedOS 6.8 with Nucleo-L432KC.
When I treid to printf the period variable it was always 0.0000. Then I modified the code to

float period = (float)1 / (float)frequency;

the result was 0.0021515.

When I passed zero to the clk.period() method, it was crash, but when I pass regular float value, code was running.

BR, Jan

1 Like

Thanks,
It worked with this statement

My code is-

#include    "select_example.h"
     
#ifdef KEY4X4       

//  Include --------------------------------------------------------------------
#include "mbed.h"
#include "Keypad.h"
#include"string.h"
#include"string"
#include<string>
#include<iostream>


//  Definition -----------------------------------------------------------------
#if (MBED_MAJOR_VERSION == 2) || (MBED_MAJOR_VERSION == 5)
#   define  WAIT_100MS()     {wait_us(100000);}
#else
#   define  WAIT_100MS()     {ThisThread::sleep_for(100ms);}
#endif

//  Object ---------------------------------------------------------------------
DigitalOut dir(D4);
PwmOut clk(D10);
DigitalOut  my_led(LED1);
//              X    Y    Z   W    A   B   C   D   OUT(XYZW), IN(ABCD)
Keypad      key(PC_3,PC_2,PC_0,PC_1,PB_0,PA_4,PA_1,PA_0);

//  RAM ------------------------------------------------------------------------

//  ROM / Constant data --------------------------------------------------------
//                          X*A = *, X*B = 7, X*C = 4, X*D = 1
//                          Y*A = 0, Y*B = 8, Y*C = 5, Y*D = 2
//                          Z*A = #, Z*B = 9, Z*C = 6, Z*D = 3
//                          W*A = A, W*B = B, W*C = C, W*D = D
//                          key_table[0]=? is not used!
const char *const key_table = "?123A456B789C*0#D";
//                              1234567890123456

//  Function prototypes --------------------------------------------------------
extern void print_revision(void);

//------------------------------------------------------------------------------
//  Control Program
//------------------------------------------------------------------------------

long enter_value()
{ uint32_t key_num,i;
uint32_t counter = 0;  
char c;
int keyoo;
int sum=0;
string lv_string = " ";
string final_string;

     print_revision();
    printf("Start Key-Pad test 4x4 keys\r\n");
    for ( i = 0; i < 3; i++) {
        while(((key_num = key.read()) == 0)) { // waiting for keypad manipulation
            WAIT_100MS();
        }
      
        c = *(key_table + key_num);   
       lv_string+=c;
        
    }
        keyoo = stoi(lv_string)
            return(keyoo);
    
}

int main()
{
    int value,rate;
    int frequency;
    float period;
    int unit_vol_time;
    clk.write(0.5);
    
    while(1)
    {
        printf("Enter the volume\n\r");
        value = enter_value();
        printf("%d",value);
        printf("\n\rEnter the rate\n\r");
        rate = enter_value();
        printf("%d",rate);
          if(rate>200)
        {
            rate=200;
        }
        
        frequency = (rate) * 212;  
        unit_vol_time = 60000 / (rate);
        
        printf("\n\rGiven rate: %d\n\r",rate);
        printf("\n\rGiven frequency: %d\n\r",frequency);
        printf("\n\rGiven Unit Volume Time: %d\n\r",unit_vol_time);
        
     dir = 0;
        
        
         while(value)
        {  
            float period = (float)1/(float)frequency;
            clk.period(period);
        
            ThisThread::sleep_for(unit_vol_time);
           //delay(unit_vol_time);//millis
            //clk.suspend();
            
            value--;
            if(value==0)
            {
               printf("Job Over\n\r"); 
            }
            
            else
            {
                printf("Volume Remaining : %d",value);
                
            }
        }
        
        
    
    
   } 
}

#endif  // #ifdef KEY4X4

Pwm problem has been solved.

I want to replicate notone() arduino function using suspend() ,but it suspends the pwm all together and i am not able to figure out where to place resume() for this code.

tone( 12, frequency );    
    delay(unit_vol_time);//millis
    noTone(12); 

Thanks for all your help
Regards
Akanksha

I gladly helped.

I did not tested it but for PWM OFF maybe you can try to set duty cycle to 0 - clk.write(0.0) and set it back to 0.5 when you will need it but I have no personal experiences with playing tones.

BR, Jan

Setting the duty cycle worked. Using Pwm OFF and ON, I intend to generate pulses for the stepper motor.
Thanks and Regards
Akanksha