SimpleIDE PWM

AS

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

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

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

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

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

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

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

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

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

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

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

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

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

AS

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.