Please examine the code and the attached serial output.
The set up loop is initialised to 0, but the first time around the loop the value selected for i is 0 and the value selected for ServoPins is 4. It should 1 and the ServoPins[i] should therefore contain 3, 4, 5, 6 but they don't, they have 4,5,6,0 which means my code is selecting the wrong servo.
What is going wrong?
[code]
#include <Servo.h>
Servo servo[4];
//constants
const byte InputPins[] = {8, 9, 10, 11};
const byte NrServos = sizeof(InputPins);
const byte ServoPins[NrServos] = {3, 4, 5, 6};
//Variables
bool previousButtonState1 = 0;
bool previousButtonState2 = 0;
int pos1 = 90; // variable to store the servo position // Crossing 1 - left gate servo
int pos2 = 90; // variable to store the servo position // Crossing 1 - right gate servo
int pos3 = 90; // variable to store the servo position // Crossing 2 - left gate servo
int pos4 = 90; // variable to store the servo position // Crossing 2 - right gate servo
void setup() {
Serial.begin(9600);
Serial.println("Start");
for (byte i = 0; i < NrServos; i++) {
Serial.println(ServoPins[i]);
Serial.println(i);
pinMode(InputPins[i], INPUT_PULLUP); // set pins to INPUT with pullup
servo[i].attach(ServoPins[i]);
servo[i].write(90); // move servo to Initial position
delay(500);
Serial.println("done");
}
Serial.println(pos1);
Serial.println(pos2);
Serial.println(pos3);
Serial.println(pos4);
Serial.println("NrServos");
Serial.println(NrServos);
Serial.println("ServoPins");
Serial.println(ServoPins[1]);
Serial.println(ServoPins[2]);
Serial.println(ServoPins[3]);
Serial.println(ServoPins[4]);
}
Serial Output
Start
3
0
done
4
1
done
5
2
done
6
3
done
90
90
90
90
NrServos
4
ServoPins
4
5
6
0
[/code]
Well, that did alter the behaviour and the correct value is now shown in the ServoPins. I have changed the rest of my code to use servo[0] etc but for some reason servo[0] does not move even though the code shows all the loop values are used. servo[1] works fine as does servo[2] and servo[3]
void loop()
{
const bool State1 = digitalRead(8); // Has crossing 1 changed?
Serial.println(State1);
if (State1 != previousButtonState1) {
previousButtonState1 = State1;
if (pos1 <= 90) // move left gate
{
Serial.println(pos1);
Serial.println("Move left gate to 179");
for (; pos1 < 179; pos1 ++)
{
servo[0].write(pos1);
Serial.println(pos1);
delay(100); // tell servo to go to position in variable 'pos'
}
}
else
{
Serial.println(pos1);
Serial.println("Move left gate to 1");
for (; pos1 >= 90; pos1 --)
{
servo[0].write(pos1);
delay(100); // tell servo to go to position in variable 'pos'
}
}
if (pos2 >=1) // move right gate
{
Serial.println(pos2);
Serial.println("Move right gate to 1");
for (; pos2 >=1; pos2 --)
{
servo[1].write(pos2);
delay(100); // tell servo to go to position in variable 'pos'
}
}
else
{
Serial.println(pos2);
Serial.println("Move right gate to 90");
for (; pos2 <90; pos2 ++)
{
servo[1].write(pos2);
delay(100); // tell servo to go to position in variable 'pos'
}
}
}
I have and the monitor shows the "Move left gate to 179" so it is being executed but the servo doesn't move.
I don't seem to be able to Serial.println the value that is in servo[0] it won't compile. Thats what I want to know
Here's the entire sketch, note the part where servo[0] moves the left gate to 179 and look at the trace from the serial monitor I posted above. The servo does not actually move, all the other three do, and correctly
[code]
#include <Servo.h>
Servo servo[4];
//constants
const byte InputPins[] = {8, 9, 10, 11};
const byte NrServos = sizeof(InputPins);
const byte ServoPins[NrServos] = {3, 4, 5, 6};
//Variables
bool previousButtonState1 = 0;
bool previousButtonState2 = 0;
int pos1 = 90; // variable to store the servo position // Crossing 1 - left gate servo
int pos2 = 90; // variable to store the servo position // Crossing 1 - right gate servo
int pos3 = 90; // variable to store the servo position // Crossing 2 - left gate servo
int pos4 = 90; // variable to store the servo position // Crossing 2 - right gate servo
void setup() {
Serial.begin(9600);
Serial.println("Start");
for (byte i = 0; i <= NrServos; i++) {
Serial.println(ServoPins[i]);
Serial.println(i);
Serial.println(Servo[i]);
pinMode(InputPins[i], INPUT_PULLUP); // set pins to INPUT with pullup
servo[i].attach(ServoPins[i]);
servo[i].write(90); // move servo to Initial position
delay(500);
Serial.println("done");
}
Serial.println(pos1);
Serial.println(pos2);
Serial.println(pos3);
Serial.println(pos4);
Serial.println("NrServos");
Serial.println(NrServos);
Serial.println("ServoPins");
Serial.println(ServoPins[0]);
Serial.println(ServoPins[1]);
Serial.println(ServoPins[2]);
Serial.println(ServoPins[3]);
}
void loop()
{
const bool State1 = digitalRead(8); // Has crossing 1 changed?
Serial.println(State1);
if (State1 != previousButtonState1) {
previousButtonState1 = State1;
if (pos1 <= 90) // move left gate
{
Serial.println(pos1);
Serial.println("Move left gate to 179");
for (; pos1 < 179; pos1 ++)
{
servo[0].write(pos1);
Serial.println(pos1);
delay(100); // tell servo to go to position in variable 'pos'
}
}
else
{
Serial.println(pos1);
Serial.println("Move left gate to 1");
for (; pos1 >= 90; pos1 --)
{
servo[0].write(pos1);
delay(100); // tell servo to go to position in variable 'pos'
}
}
if (pos2 >= 1) // move right gate
{
Serial.println(pos2);
Serial.println("Move right gate to 1");
for (; pos2 >= 1; pos2 --)
{
servo[1].write(pos2);
delay(100); // tell servo to go to position in variable 'pos'
}
}
else
{
Serial.println(pos2);
Serial.println("Move right gate to 90");
for (; pos2 < 90; pos2 ++)
{
servo[1].write(pos2);
delay(100); // tell servo to go to position in variable 'pos'
}
}
}
const bool State2 = digitalRead(9); // Has crossing 2 changed?
if (State2 != previousButtonState2) {
previousButtonState2 = State2;
if (pos3 <= 90) //move left gate
{
for (; pos3 < 179; pos3 ++)
{
servo[2].write(pos3);
delay(100); // tell servo to go to position in variable 'pos'
}
}
else
{
for (; pos3 >= 90; pos3 --)
{
servo[2].write(pos3);
delay(100); // tell servo to go to position in variable 'pos'
}
}
if (pos4 >= 1)
{
for (; pos4 >= 1; pos4 --) // move right gate
{
servo[3].write(pos4);
delay(100); // tell servo to go to position in variable 'pos'
}
}
else
{
for (; pos4 < 90; pos4 ++)
{
servo[3].write(pos4);
delay(100); // tell servo to go to position in variable 'pos'
}
}
}
}
[/code]
But not consistently. I guess you copied some parts of the code from others, but when you came to adding more code to it, you forgot about using arrays. These should be arrays:
bool previousButtonState1 = 0;
bool previousButtonState2 = 0;
int pos1 = 90; // variable to store the servo position // Crossing 1 - left gate servo
int pos2 = 90; // variable to store the servo position // Crossing 1 - right gate servo
int pos3 = 90; // variable to store the servo position // Crossing 2 - left gate servo
int pos4 = 90;
Any time you find yourself declaring variables with the same name except for a number, that should almost certainly be an array.
Blockquote It's good to see you using arrays in your code:
Servo servo[4];
```/quote
As a programmer with over 40 years experience (not in C++) I agree with you, but this was a quick test rig build and I copied chunks of code from samples. The aesthetics can always be improved later, I need it to work and right now it doesn't and I cannot find out why. Hence my questions. It seems there might be a hardware issue, I'll need to do some more testing by switching servos around to see if it make a difference.
Try swapping the wires between the non-working servo and a working servo. This will help you diagnose whether the problem is with the servo or the Arduino.
