I've seen it posted several times, just didn't understand why. This is due to inexperience. So I did a search.
I think even at the top of Project Guidance forum there is a thread "several things at the same time". After reading this tutorial from Adafruit, I now get it.
Thank you Adafruit and all the many people in this forum, who have given me guidance over this last year.
A bit of advice from a newby to another newby. STOP copying code. If you really want to learn it, Type it out yourself. Eventually, you'll get it. That doesn't mean you can't use someone else's code. It's on here, it's public domain and assumed for free use to copy. Print it out or do a split screen and retype it!
marine_hm:
A bit of advice from a newby to another newby. STOP copying code. If you really want to learn it, Type it out yourself.
Yes, that's something that surprised me a bit when I first started using this forum. The sheer number of people copying code snippets without much of a clue as to what they're doing. Hence the large number of questions here that read something like:
"Making two programs work at the same time."
or
"Help, programs work great separately but how can I make them run together"
@Robin2; I just finished reading the entire thread on your "Demonstration code for several things at the same time". Is the original code #1 still valid?
I see there are several ways of skinning a cat, understand that you were teaching a concept, not a specific way of coding.
I may not have understood all of the code as it is, but the concept is clear. Thank you!!!
I small snippet of Adafruit's sketch; I have a question. Something I have not seen before;
"public" What is this...?
Led1 and sweeper2 will not be updated when the button is pressed.
Copy Code
#include <Servo.h>
class Flasher
{
// Class Member Variables
// These are initialized at startup
int ledPin; // the number of the LED pin
long OnTime; // milliseconds of on-time
long OffTime; // milliseconds of off-time
// These maintain the current state
int ledState; // ledState used to set the LED
unsigned long previousMillis; // will store last time LED was updated
// Constructor - creates a Flasher
// and initializes the member variables and state
public:
Flasher(int pin, long on, long off)
{
ledPin = pin;
pinMode(ledPin, OUTPUT);
OnTime = on;
OffTime = off;
ledState = LOW;
previousMillis = 0;
}
void Update()
{
// check to see if it's time to change the state of the LED
unsigned long currentMillis = millis();
if((ledState == HIGH) && (currentMillis - previousMillis >= OnTime))
{
ledState = LOW; // Turn it off
previousMillis = currentMillis; // Remember the time
digitalWrite(ledPin, ledState); // Update the actual LED
}
else if ((ledState == LOW) && (currentMillis - previousMillis >= OffTime))
{
ledState = HIGH; // turn it on
previousMillis = currentMillis; // Remember the time
digitalWrite(ledPin, ledState); // Update the actual LED
}
}
};
"public" is part of the C++ language. So is "private".
"public" says that everything following (until "private", which is not present) such as Update and the Flasher constructor are available publicly for anyone to use.
Typing this sketch; line by line from adafruit, when I ran across "public". Lines 18 and 59 below.
It compiles just fine. I just want to understand.
Thanks for your replies.
#include <Servo.h>
class Flasher
{
// Class Member Variables
// These are initialized at startup
int ledPin; // the number of the LED pin
long OnTime; // milliseconds of on-time
long OffTime; // milliseconds of off-time
// These maintain the current state
int ledState; // ledState used to set the LED
unsigned long previousMillis; // will store last time LED was updated
// Constructor - creates a Flasher
// and initializes the member variables and state
public:
Flasher(int pin, long on, long off)
{
ledPin = pin;
pinMode(ledPin, OUTPUT);
OnTime = on;
OffTime = off;
ledState = LOW;
previousMillis = 0;
}
void Update()
{
// check to see if it's time to change the state of the LED
unsigned long currentMillis = millis();
if ((ledState == HIGH) && (currentMillis - previousMillis >= OnTime))
{
ledState = LOW; // Turn it off
previousMillis = currentMillis; // Remember the time
digitalWrite(ledPin, ledState); // Update the actual LED
}
else if ((ledState == LOW) && (currentMillis - previousMillis >= OffTime))
{
ledState = HIGH; // turn it on
previousMillis = currentMillis; // Remember the time
digitalWrite(ledPin, ledState); // Update the actual LED
}
}
};
class Sweeper
{
Servo servo; // the servo
int pos; // current servo position
int increment; // increment to move for each interval
int updateInterval; // interval between updates
unsigned long lastUpdate; // last update of position
public:
Sweeper(int interval)
{
updateInterval = interval;
increment = 1;
}
void Attach(int pin)
{
servo.attach(pin);
}
void Detach()
{
servo.detach();
}
void Update()
{
if ((millis() - lastUpdate) > updateInterval) // time to update
{
lastUpdate = millis();
pos += increment;
servo.write(pos);
Serial.println(pos);
if ((pos >= 180) || (pos <= 0)) // end of sweep
{
// reverse direction
increment = -increment;
}
}
}
};
Flasher led1(11, 123, 400);
Flasher led2(12, 350, 350);
Flasher led3(13, 200, 222);
Sweeper sweeper1(15);
Sweeper sweeper2(25);
void setup()
{
Serial.begin(9600);
sweeper1.Attach(9);
sweeper2.Attach(10);
}
void loop()
{
sweeper1.Update();
if (digitalRead(2) == HIGH)
{
sweeper2.Update();
led1.Update();
}
led2.Update();
led3.Update();
}
marine_hm:
No, sorry. It is the sketch from adafruit mentioned in original post.
That does not make sense. You asked a question in Reply #4 (" Is the original code #1 still valid?") which I had assumed referred to the code I had written rather than to the Adafruit code. I have not been able to answer your question because you have not yet clarified what your question referred to.
Agreed about typing out code even if copying. I did that and it helped immensely. Didn't do split screen with unlimited looking back and forth, I put the source window away and typed as much as I could remember in echoic memory. Naturally helps the brain process the syntax and then you start seeing it in larger and larger chunks. There is no shortcut here. You learn letters before words before sentences before novels.
.