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[Reply #15 on:]

Not offended.  SImply trying to encourage curiosity and exploration.

[Reply #16 on:]

Given that your project appears to be at its start I'll throw this one out there.

It does make use of a non-standard feature of the GCC/CPP compiler included with the Arduino IDE and thus I feel fair game but it may be non portable to other compilers - the range based 'case' statements associated with the standard 'switch'/'case' pair.

Code:

#include <Servo.h>

const uint8_t   pinSERVO    = 9;

float           pos         = 0;    // variable to store the rotary switch input
Servo           servo;

void loop()
{
    // ... 'analogRead' will return a value in the range 0 - 1023
    switch ( analogRead(A0) )
    {
        case    0 ...   99:             return;
        case  200 ...  299:             return;
        case  400 ...  499:             return;
        case  700 ...  799:             return;


        case  100 ...  199: pos =  10;  break;
        case  300 ...  399: pos =  13;  break;
        case  500 ...  599: pos =  20;  break;
        case  600 ...  699: pos =  25;  break;
        case  800 ...  899: pos =  30;  break;
        case  900 ... 1023: pos = 120;  break;
    }

    servo.write(pos);
}

void setup()
{
    servo.attach(pinSERVO);
    servo.write(pos);               // arm speed controller
    delay(3000);
}

[Reply #17 on:]

Hi,

 I've modified my code without the goto's and the program is working ok

Code:

#include <Servo.h>

Servo myservo1;  // create servo object to control a servo
// a maximum of eight servo objects can be created

float pos = 0;    // variable to store the rotary switch input



void setup() {
  myservo1.attach(9);  // attaches the servo on pin 9 to the servo object
  myservo1.write(pos);
  delay(3000);
}

// the loop routine runs over and over again forever:
void loop() {

  int sensorValue = analogRead(A0);
  if (sensorValue > 100 && sensorValue < 200) {
    pos=10;
  }
  else if (sensorValue > 200 && sensorValue < 400) {
    pos=13;
  }
  else if (sensorValue > 400 && sensorValue < 600) {
    pos=14;
  } 
  else if (sensorValue > 600 && sensorValue < 700) {
    pos=15;
  }
  else if (sensorValue > 700 && sensorValue < 900) {
    pos=16;
  }
  else if (sensorValue > 900) {
    pos=17;
  }


  myservo1.write(pos);

}

But then I added a basic rise and fall code for the first rotary switch position but get the error:
_13_prog.cpp: In function 'void loop()':
_13_prog:44: error: 'else' without a previous 'if'

I removed the else and the code compiled, but when I tested the air raid it only ran the rise and fall code and not the other switch positions

Code:

#include <Servo.h>

Servo myservo1;  // create servo object to control a servo
// a maximum of eight servo objects can be created

float pos = 0;    // variable to store the rotary switch input



void setup() {
  myservo1.attach(9);  // attaches the servo on pin 9 to the servo object
  myservo1.write(pos);
  delay(3000);
}

// the loop routine runs over and over again forever:
void loop() {

  int sensorValue = analogRead(A0);
  if (sensorValue > 100 && sensorValue < 200)
   {
    pos=12.5;
  }
  // rise and fall code                     
  for(pos = 12.5; pos < 15; pos += .1)  // goes from 12.5  to 15
  {                                  // in steps of .1 
    myservo1.write(pos);              // tell servo to go to position in variable 'pos'
    delay(25);                       // waits 15ms for the servo to reach the position
  }

  delay(5000);

  for(pos = 15; pos>=12.5; pos-=.1)     // goes from 15  to 12.5
  {                               
    myservo1.write(pos);              // tell servo to go to position in variable 'pos'
    delay(25);                       // waits 15ms for the servo to reach the position
  }


   else if (sensorValue > 200 && sensorValue < 400) // error on this line
  {
    pos=13;
  }
  else if (sensorValue > 400 && sensorValue < 600) {
    pos=14;
  } 
  else if (sensorValue > 600 && sensorValue < 700) {
    pos=15;
  }
  else if (sensorValue > 700 && sensorValue < 900) {
    pos=16;
  }
  else if (sensorValue > 900) {
    pos=17;
  }


  myservo1.write(pos);

}

Where am I going wrong with this piece of code? Any infomation would be gratefully recieved

Regards

Dale

[Reply #18 on:]

Dale, the simple format of if is

if (condition)
{
    code  if true
}

In your case you need to put everything you want to happen "if true" within those braces:

Code:

...
  if (sensorValue > 100 && sensorValue < 200)
   {
      set position
      rise code
      delay
      fall code                     
   }
   else if (sensorValue > 200 && sensorValue < 400)
... etc

Keeping things indented properly helps you keep track of the braces.  And the auto-format tool also.  (on the Tools Menu)

Cheers,
John

[Reply #19 on:]

Thanks John,

Code modified and running ok, much appreciated.

Hazzard thanks for the upload, I was thinking more of a count then time based, but thinking more about it, if i did go down the count method I would need to have a way to re-set the counter and time based is maybe the way to go. Hmm my hurts. I need to wire these switches to my breadboard and start experimenting.

Regards

Dale

[Reply #20 on:]

Hi,

I thought I had it sorted when I testing last night, the wife was giving me the evil eye on testing the siren so late. turns out that it is not rising and falling. I think it's due to it doing everthing between the braces which is increment up .1  then delay and then increment down .1 which keeps the speed the same, which is whats happining. I posted the code below with better coments

Code:

void loop() {

  int sensorValue = analogRead(A0);
  if (sensorValue > 100 && sensorValue < 200)
  {
   

    // rise and fall code                     
    for (pos = 12.5; pos < 18; pos += .1)  // goes from 12.5  to 12.6
            myservo1.write(pos);              // tell servo to go to position in variable 'pos'
    delay(25);                       // waits 15ms for the servo to reach the position
// because there is no braces code does not loop and reach pos 18, but moves onto next line

    delay(1000);

    for (pos = 18; pos>=12.5; pos-=.1)     // this one is odd as I should hear it jump from 12.6 to 18
                                                           //  but it seems a constant speed, no change in sound anyway

      myservo1.write(pos);              // tell servo to go to position in variable 'pos'
    delay(25);                       // waits 15ms for the servo to reach the position
  }                                       // loop back

 

I went back to I to an old program just to check it worked with the braces and it did code below.

Code:

void loop()
{

  for(pos = 12.5; pos < 18; pos += .1)  // goes from 12.5 degrees to 18 degrees in .1 increments
  {                                 
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(15    );      // waits 15ms for the servo to reach the position
  }
// loop until pos = 18
  {

    delay (5000); 

  }
  for(pos = 18; pos>=12.5; pos-=.1)     // goes from 18  to 12.5  in .1 increments
  {                               
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(15);                       // waits 15ms for the servo to reach the position
  }
// loop until pos = 12.5
}

Am I on the right lines in my thinking, seems it's a formatting error but I don't know the correct format. Any information gratefully recieved

Regards

Dale

[Reply #21 on:]

What type is pos? If it is an int, than you can't assign 12.5 to it. Writing 12.5 to a servo doesn't make sense, either, since the Servo::write() method expects an int.

Code:

// because there is no braces code does not loop and reach pos 18, but moves onto next line

Well, you ought to have them, even if they are not strictly needed. Having them makes them look like you know what you are doing.

If you didn't add this comment, why have you ignored it?

The other code has some braces that you need and some that you do not. You need to learn to tell the difference.

[Reply #22 on:]

Yes Dale.

"More cowbells!  I need more cowbells!"

cowbells == braces

http://arduino.cc/en/Reference/Braces
http://www.cplusplus.com/doc/tutorial/control/

And put the delay(25) inside them, so it will be part of your for loop

John

[Reply #23 on:]

Hi paul

I'll post the entire code below

Code:

#include <Servo.h>

Servo myservo1;  // create servo object to control a servo
// a maximum of eight servo objects can be created

float pos = 0;    // variable to store the rotary switch input



void setup() {
  myservo1.attach(9);  // attaches the servo on pin 9 to the servo object
  myservo1.write(pos);
  delay(3000);
}

// the loop routine runs over and over again forever:
void loop() {

  int sensorValue = analogRead(A0);
  if (sensorValue > 100 && sensorValue < 200)
  {
   // pos=12.5;

    // rise and fall code                     
    for (pos = 12.5; pos < 18; pos += .1)  // goes from 12.5  to 18
                                                          // in steps of .1 
      myservo1.write(pos);              // tell servo to go to position in variable 'pos'
    delay(25);                       // waits 15ms for the servo to reach the position


    delay(1000);

    for (pos = 18; pos>=12.5; pos-=.1)     // goes from 18  to 12.5 

      myservo1.write(pos);              // tell servo to go to position in variable 'pos'
    delay(25);                       // waits 15ms for the servo to reach the position
  }

  else if (sensorValue > 200 && sensorValue < 400) // error on this line
  {
    pos=13;
  }
  else if (sensorValue > 400 && sensorValue < 600) {
    pos=14;
  } 
  else if (sensorValue > 600 && sensorValue < 700) {
    pos=15;
  }
  else if (sensorValue > 700 && sensorValue < 900) {
    pos=16;
  }
  else if (sensorValue > 900) {
    pos=17;
  }


  myservo1.write(pos);

}


Pos is a float as I want more control over the rise and fall of my motor

Well, you ought to have them, even if they are not strictly needed. Having them makes them look like you know what you are doing.

If you didn't add this comment, why have you ignored it?

The other code has some braces that you need and some that you do not. You need to learn to tell the difference.

I don't think I explained it very well, originally I had it with braces but I got an error with my else before if statement, to get the program to compile as john pointed out i need to place all the rise a fall code in between the braces. but this causes the program to loop the  rise and fall part between the braces.

Regards

Dale

P.S. John just posted as i was writing this, cheers I'll check those links out right now

[Reply #24 on:]

If statements need braces
for loops need braces
while loops need braces
... etc

Almost everything almost always needs braces

[Reply #25 on:]

Code:

float pos = 0;    // variable to store the rotary switch input
    for (pos = 12.5; pos < 18; pos += .1)  // goes from 12.5  to 18
                                                          // in steps of .1 
      myservo1.write(pos);              // tell servo to go to position in variable 'pos'

I fail to see where any rotary switch is read. So, the initial comment is crap.

The only place that pos is used is to position the servo. The Servo::write() function takes an int.

So, why is pos a float?

The Tools + Auto Format function would do an excellent job of properly indenting your code, so you can see where braces are missing. Indenting a statement doesn't mean squat to the compiler. But, it means a lot to people reading the code. Properly indented code has the same meaning to people and to compilers. The auto format tool makes the indenting match how the compiler will understand the code. It can, then, be quite obvious that how you understand it and how the compiler will understand it are not the same thing.

I can not stress the importance of properly indented code enough. Yours, of course, is not.

johncc's comment regarding braces is nonsense. If statements, and for and while loops, may or may not need braces. It is recommended that they always be used, so that you can add a statement to the block,  and be sure that the statement is executed the correct number of times. Switch statements always need braces.

Functions always need curly braces. Almost any other use of curly braces (except in array initializations) is unnecessary.

[Reply #26 on:]

John thanks for the second link, I've done a copy and paste

Here is an example of countdown using a for loop:
 




1234567891011
// countdown using a for loop
#include <iostream>
using namespace std;
int main ()
{
  for (int n=10; n>0; n--) {
    cout << n << ", ";
  }
  cout << "FIRE!\n";
  return 0;
}
10, 9, 8, 7, 6, 5, 4, 3, 2, 1, FIRE!

I don't think there is a better way to learn then to see an example of how its done.
Here is my working code: with better comments

Code:

#include <Servo.h>

Servo myservo1;  // create servo object to control a servo
// a maximum of eight servo objects can be created

float pos = 0;    // variable to store the rotary switch input



void setup() {
  myservo1.attach(9);  // attaches the servo on pin 9 to the servo object
  myservo1.write(pos);
  delay(3000);
}

// the loop routine runs over and over again forever:
void loop() {

  int sensorValue = analogRead(A0); // read value from rotary switch
  if (sensorValue > 100 && sensorValue < 200) // rotary switch position 1
  {


    // rise and fall code                      
    for (pos = 12.5; pos < 18; pos += .1){  // goes from 12.5  to 15
      // in steps of .1  
      myservo1.write(pos);              // tell servo to go to position in variable 'pos'
      delay(25);                       // waits 15ms for the servo to reach the position
    }

    delay(3000);

    for (pos = 18; pos>=12.5; pos-=.1) {    // goes from 15  to 12.5  

      myservo1.write(pos);              // tell servo to go to position in variable 'pos'
      delay(25);     // waits 15ms for the servo to reach the position
    }
  }
  else if (sensorValue > 200 && sensorValue < 400) // rotary switch position 2
  {
    pos=13;
  }
  else if (sensorValue > 400 && sensorValue < 600) {// rotary switch position 3
    pos=14;
  }  
  else if (sensorValue > 600 && sensorValue < 700) {// rotary switch position 4
    pos=15;
  }
  else if (sensorValue > 700 && sensorValue < 900) {// rotary switch position 5
    pos=16;
  }
  else if (sensorValue > 900) {// rotary switch position 6
    pos=17;
  }


  myservo1.write(pos);

}

I really happy with how the program is coming along, due to all the help I have recieved. Next thing on my to do list is wire the switches to my breadboard and start experimenting.

John I was looking Jeremy Blum vid on youtube and seen a familiar name in the recommendations John NYCCNC is that you?
I've subscribed anyway, lots of very interesting vids to look at. I am a cnc'er myself, I've got a small vmc which I also use to turn small parts on which is what I made the air raid on, I've also biult my own router table.

Regards

Dale

[Reply #27 on:]

Oops

 I have'nt been doing a good job on my comments,I was going to tidy them when I got a finally rev of the program but can see this one is misleading.

float pos = 0;    // variable to store the rotary switch input

now reads

float pos = 0;    // variable for servo positon

regards

Dale

[Reply #28 on:]

now reads

Fixing the comment is far less important than fixing the underlying problem which is that pos should be an int, not a float.

[Reply #29 on:]

Functions always need curly braces. Almost any other use of curly braces (except in array initializations) is unnecessary.

Right.  But my point was simply that I think the curly braces below are necessary, and arduinodale didn't have them

Code:

    for (pos = 12.5; pos < 18; pos += .1){  // goes from 12.5  to 15
      // in steps of .1 
      myservo1.write(pos);              // tell servo to go to position in variable 'pos'
      delay(25);                       // waits 15ms for the servo to reach the position
    }