SimpleIDE PWM

AS · 2016-02-04 12:59

I´m looking for a simple example to change the intensity of a led with PWM, I can´t found any.
I do this with SPIN and I want to know how use PWM with SimpleIDE.
I think is something with

pulse_out (int pin, int time)

Thanks

DavidZemon · 2016-02-04 13:56

Check out the pwm_set, pwm_start and pwm_stop functions.

I think there's a way to search SimpleIDE for these functions too, but I just searched "pwm" at the top-right of http://david.zemon.name/PropWare and found this
http://david.zemon.name/PropWare/simpletools_8h.xhtml#a57f683188c3dd35ee0574ff349835682

AS · 2016-02-04 14:15

Thanks you!

I will try do something simple. I ask it here without try nothing, because I thought that should be a example in the (http://learn.parallax.com).

AS · 2016-02-04 17:30

DavidZemon,

This code is working ok:

#include "simpletools.h"           // Include simpletools                    

int main()                                  // main function
{

  int Led_Intensity=0;
  pwm_start (1000);
  
  while(1)                                    // Endless loop
  {
    
    while (Led_Intensity<1000)
    {
      pwm_set (0,1,Led_Intensity);
      Led_Intensity ++;
      pause (1);
    }  
    
          
    while (Led_Intensity>0)
    {
      pwm_set (0,1, Led_Intensity);
      Led_Intensity --;
      pause (1);
    }      

  }
}

I have two simple questions for now:
1 - The channel of pwm_set can be "0" or "1" it is the Counter Modules for each COG "ctra" and "ctrb". Right?
2 - Now I´m trying to control the Led with the LabView, at this moment I have only one question.
How I should to do to convert a string from the array to a integer? In the Arduino I do something like:

number = String(c[index]).toInt();

Where can I see information to convert strings and numbers?

Thank you

DavidZemon · 2016-02-04 21:06

Lots of different options for that, depending on how flexible you want it to be. In this case, you could choose the highly inflexible, but very compact solution:

int number = c[index] - '0';

Or that's the equivalent of

int number = c[index] - 0x30;

This is because the ASCII value for a zero is 0x30. And the ASCII value for a one is 0x31. See http://www.asciitable.com/.
Of course, you might notice this only works for single digits

If you need a solution that works for many digits, but always whole numbers and only numbers, then you can use atoi (array to integer) or atol (array to long).

int number = atoi(c);

Notice that this time I did not use c[index], but c instead. This is because atoi and atol require "C-string"s. That is another way to say "null-terminated character array". Or, more importantly, more than a single character. Most of time, this is how people deal with input from the terminal: they read in whole strings at a time, rather than individual bytes. So, this method is easier than the first that I mention, but it requires modifying the rest of your code to read strings instead of bytes from LabView.

Finally, there's sscanf. This is like the reverse of printf. You give it a formatted string and it breaks up the words into the values you want. I wouldn't recommend it for this specific application, but the documentation is worth a glance so that you know what tools are in your toolbox

DavidZemon · 2016-02-04 21:08

AS wrote: »

1 - The channel of pwm_set can be "0" or "1" it is the Counter Modules for each COG "ctra" and "ctrb". Right?]

I don't have the code in front of me, so I can't confirm it... but your guess sounds like a very good one to me.

AS · 2016-02-04 23:26

I already try 1001 different situations and I can´t do this

I need your help!

The LabView is sending something like:
"ok0," or "ok78," or "ok675," or "ok1000,"
I can change it, if you think usefull.

I go post the code just for you laugh a little

, the real reason is to let you understand how I´m thinking to do this

, of course when this run it is possible to simplify.

#include "simpletools.h"                      // Include simpletools                    


int main()                                    // main function
{
  int index;
  int Led_Intensity_I[4];
  int Led_Intensity;
  char c[10];
  pwm_start (1000);
  
  
  while(1)                                    // Endless loop
  {

    index = 0;
    Led_Intensity_I[0] = 0;
    Led_Intensity_I[1] = 0;    
    Led_Intensity_I[2] = 0;     
    Led_Intensity = 0;    
    
    
    
    while (index<7)            // "ok????,"  Get string from LabView
    {                          //  0123456
      c[index] = getChar();
      index ++;
    }  
    
    

    //////////////////////// Try to make the number :P ///////////////////////////////////////
    if (c[3]==',')   //////////// if the number is between 0 - 9 /////////////
    {
      int (Led_Intensity = c[2] - 0x30);
    }
    
    if (c[4]==',')    //////////// if the number is between 10 - 99 /////////////
    {
      int (Led_Intensity_I[0] = c[2] - 0x30);
      int (Led_Intensity_I[1] = c[3] - 0x30);
      Led_Intensity = Led_Intensity_I[0]*10 + Led_Intensity_I[1];
    }
    
    if (c[5]==',')    //////////// if the number is between 100 - 999 /////////////
    {
      int (Led_Intensity_I[0] = c[2] - 0x30);
      int (Led_Intensity_I[1] = c[3] - 0x30);
      int (Led_Intensity_I[2] = c[4] - 0x30);
      Led_Intensity = Led_Intensity_I[0]*100 + Led_Intensity_I[1]*10 + Led_Intensity_I[2];
    }  
    
    if (c[6]==',')   //////////// if the number is 1000 /////////////
    {
      Led_Intensity = 1000;
    }            
    
    //////////////////////////////////////////////////////////////////////////////////////////
    
    index = 0;
    while (index<7)         // send back the received string
    {
      printi("%c", c[index]);
      index ++;
    }   
             
    pwm_set (0,1,Led_Intensity); // send to the Led the PWM
    
    pause (20);
    
 }   
}

I think the best solution for me is to do something like:

int number = c[index] - 0x30;

Because I want send numbers and letters each cycle!? (from the LabView)

I think I don´t understand when you said: "highly inflexible" :P, I already done similar tasks with SPIN and C (to Arduino) and I think it was much easier, maybe because are more information and examples. I hope you can help me!
Thanks

AS · 2016-02-05 00:04

The code like this don´t give any warnings or errors but don´t work :P:

#include "simpletools.h"                      // Include simpletools                    


int main()                                    // main function
{
  int index;
  int Led_Intensity=0;
  int Led_Intensity_aux1=0;
  int Led_Intensity_aux2=0;
  int Led_Intensity_aux3=0;  
  char c[10];
  pwm_start (1000);
  
  
  while(1)                                    // Endless loop
  {

    index = 0;
    
    while (index<7)            // "ok????,"  Get string from LabView
    {                          //  0123456
      c[index] = getChar();
      index ++;
    }  
    
    if (c[3]==',')
    {
      Led_Intensity = c[2] - '0';
    }
    
    if (c[4]==',')
    {
      Led_Intensity_aux1 = c[2] - '0';
      Led_Intensity_aux2 = c[3] - '0';
      Led_Intensity = Led_Intensity_aux1*10 + Led_Intensity_aux2;
    }
    
    if (c[5]==',')
    {
      Led_Intensity_aux1 = c[2] - '0';
      Led_Intensity_aux2 = c[3] - '0';      
      Led_Intensity_aux3 = c[4] - '0';       
      Led_Intensity = Led_Intensity_aux1*100 + Led_Intensity_aux2*10 + Led_Intensity_aux3;
    }  
    
    if (c[6]==',')
    {
      Led_Intensity = 1000;
    }   
    
    index = 0;
    while (index<7)         // send back the received string
    {
      printi("%c", c[index]);
      index ++;
    }          
          
    pwm_set (0,1,Led_Intensity);
    
    pause(20);
    
 }   
}

Any sugestion? Please!

Ariba · 2016-02-05 00:43

Your code looks quite complicated. I would parse the characters while they arrive, without storing them in a string first.
The following code shows what I mean, but be aware that it's untested:

#include "simpletools.h"                      // Include simpletools                    


int main()                                    // main function
{
  int Led_Intensity;
  char c;

  pwm_start (1000);
  
  while(1)                                    // Endless loop
  {

    Led_Intensity = 0;
    c = 0;

    while(c != 'o')  getChar();		     // wait for 'o'
    if(getchar() != 'k') continue;           // restart loop if not 'k'
    while(c != ',')			     // get dec-value from LabView
    {
      c = getChar();
      if(c>='0' && c<='9')  Led_Intensity = Led_Intensity*10 + (c-'0');
    }  

    pwm_set (0,1,Led_Intensity);    
  }   
}

Andy

AS · 2016-02-05 02:41

Aribe,

At this moment your code is not working right, I will see it better and I will have some question about it for sure :P
I´m getting some issues with the "getChar()" I think I will need use "fdserial".

Thanks a lot for the example you sent.

DavidZemon · 2016-02-05 02:51

AS wrote: »

I´m getting some issues with the "getChar()" I think I will need use "fdserial".

Thanks a lot for the example you sent.

At brief glance, ariba's code looks good (as usual

). The only issue I see right away is that he mixed cases on the getChar. Perhaps that is the issue you're running into?

AS · 2016-02-05 15:53

Ariba,
Thanks a lot (again) your code is Fantastic!
I learn with your code. But I don´t understand why "gerchar()" is not working here

The code that is running here is with "fdserial.h":

#include "simpletools.h"                      // Include simpletools       
#include "fdserial.h" 

fdserial *LabView;             


int main()                                    // main function
{
  LabView = fdserial_open(31, 30, 0, 115200);  
  pause(500);
  int Led_Intensity;
  char c;

  pwm_start (1000);
  
  while(1)                                    // Endless loop
  {

    Led_Intensity = 0;
    c = 0;
    fdserial_rxFlush(LabView);

    while(c != 'o')      	                 // wait for 'o'
    {
      c = fdserial_rxChar(LabView);
    }      
    
    if(fdserial_rxChar(LabView) != 'k') continue;           // restart loop if not 'k'
    
    while(c != ',')			     // get dec-value from LabView
    {
      c = fdserial_rxChar(LabView);
      if(c>='0' && c<='9')  Led_Intensity = Led_Intensity*10 + (c-'0');
    }  

    pwm_set (0,1,Led_Intensity);    
    pause(20);
  }   
}

Ariba and DavidZemon, I hope you can help me understand what is the issue with "gertchar()"

DavidZemon I want to see PropWare running this, I want try it, but at this moment I need to understand the other issue (http://forums.parallax.com/discussion/163457/simpleide-fdserial-h#latest).

Your help has been fantastic!

Electrodude · 2016-02-05 17:54

What was the error message with "getchar()"? Did you just not define it, or was it something else?

AS · 2016-02-05 18:36

Hi Eletrodude! No error message with "getchar()". I just can´t control the Led_Intensity, it´s off all the time.
The issue here is very similar with the other one (http://forums.parallax.com/discussion/163457/simpleide-fdserial-h#latest). With "fdserial.h" is everything ok but with "getchar()" I just can´t understand why it is not working.

SimpleIDE PWM

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