Function Error.. New and Stumped.

Projects Programming
1

Im trying to build my own boost gauge using a seven segment display, arduino uno, and a pressure sensor. the code I have so far is giving me an error can anyone help me out? I don't know what the problem is?

The problem is somehow with the calling of the function. However I don't know what changes to make?

ERROR
Boost_Final.cpp.o: In function loop': C:\Program Files (x86)\Arduino/Boost_Final.ino:179: undefined reference to writenum(int, int)'
collect2.exe: error: ld returned 1 exit status
Error compiling.

CODE
void setup() {
pinMode (2, OUTPUT);
pinMode (3, OUTPUT);
pinMode (4, OUTPUT);
pinMode (5, OUTPUT);
pinMode (6, OUTPUT);
pinMode (7, OUTPUT);
pinMode (8, OUTPUT);
pinMode (9, OUTPUT);
pinMode (10, OUTPUT);
pinMode (11, OUTPUT);
pinMode (12, OUTPUT);
pinMode (13, OUTPUT);
}

void loop() {

int digit;
int num;

void writenum(int digit, int num);
{
if (digit==1){

analogWrite(10, HIGH); // Chooses digit ? and lights up what are grounded
analogWrite(11, LOW); // Chooses digit ? and lights up what are grounded
analogWrite(12, LOW); // Chooses digit ? and lights up what are grounded
analogWrite(13, LOW); // Chooses digit ? and lights up what are grounded
}
else if (digit==2){

analogWrite(10, HIGH); // Chooses digit ? and lights up what are grounded
analogWrite(11, LOW); // Chooses digit ? and lights up what are grounded
analogWrite(12, LOW); // Chooses digit ? and lights up what are grounded
analogWrite(13, LOW); // Chooses digit ? and lights up what are grounded
}
else if (digit==3){

analogWrite(10, HIGH); // Chooses digit ? and lights up what are grounded
analogWrite(11, LOW); // Chooses digit ? and lights up what are grounded
analogWrite(12, LOW); // Chooses digit ? and lights up what are grounded
analogWrite(13, LOW); // Chooses digit ? and lights up what are grounded
}
else if (digit==4){

analogWrite(10, HIGH); // Chooses digit ? and lights up what are grounded
analogWrite(11, LOW); // Chooses digit ? and lights up what are grounded
analogWrite(12, LOW); // Chooses digit ? and lights up what are grounded
analogWrite(13, LOW); // Chooses digit ? and lights up what are grounded
}

if (num==0){
analogWrite(2, LOW); // Ground the segment a
analogWrite(3, LOW); // Ground the segment b
analogWrite(4, LOW); // Ground the segment c
analogWrite(5, LOW); // Ground the segment d
analogWrite(6, LOW); // Ground the segment e
analogWrite(7, LOW); // Ground the segment f
analogWrite(8, HIGH); //
analogWrite(9, HIGH); //
}

else if (num==1){
analogWrite(2, LOW); // Ground the segment a
analogWrite(3, LOW); // Ground the segment b
analogWrite(4, HIGH); //
analogWrite(5, HIGH); //
analogWrite(6, HIGH); //
analogWrite(7, HIGH); //
analogWrite(8, HIGH); //
analogWrite(9, HIGH); //
}
else if (num==2){
analogWrite(2, LOW); // Ground the segment a
analogWrite(3, HIGH); //
analogWrite(4, LOW); // Ground the segment c
analogWrite(5, LOW); // Ground the segment d
analogWrite(6, HIGH); //
analogWrite(7, LOW); // Ground the segment f
analogWrite(8, LOW); // Ground the segment g
analogWrite(9, HIGH); //
}
else if (num==3){
analogWrite(2, LOW); // Ground the segment a
analogWrite(3, LOW); // Ground the segment b
analogWrite(4, LOW); // Ground the segment c
analogWrite(5, HIGH); //
analogWrite(6, HIGH); //
analogWrite(7, LOW); // Ground the segment f
analogWrite(8, LOW); // Ground the segment g
analogWrite(9, HIGH); //
}
else if (num==4){
analogWrite(2, LOW); // Ground the segment a
analogWrite(3, LOW); // Ground the segment b
analogWrite(4, HIGH); //
analogWrite(5, HIGH); //
analogWrite(6, LOW); // Ground the segment e
analogWrite(7, HIGH); //
analogWrite(8, LOW); // Ground the segment g
analogWrite(9, HIGH); //
}
else if (num==5){
analogWrite(2, HIGH); //
analogWrite(3, LOW); // Ground the segment b
analogWrite(4, LOW); // Ground the segment c
analogWrite(5, HIGH); //
analogWrite(6, LOW); // Ground the segment e
analogWrite(7, LOW); // Ground the segment f
analogWrite(8, LOW); // Ground the segment g
analogWrite(9, HIGH); //
}
else if (num==6){
analogWrite(2, HIGH); //
analogWrite(3, LOW); // Ground the segment b
analogWrite(4, LOW); // Ground the segment c
analogWrite(5, LOW); // Ground the segment d
analogWrite(6, LOW); // Ground the segment e
analogWrite(7, LOW); // Ground the segment f
analogWrite(8, LOW); // Ground the segment g
analogWrite(9, LOW); // Ground the segment DP
}
else if (num==7){
analogWrite(2, LOW); // Ground the segment a
analogWrite(3, LOW); // Ground the segment b
analogWrite(4, HIGH); //
analogWrite(5, HIGH); //
analogWrite(6, HIGH); //
analogWrite(7, LOW); // Ground the segment f
analogWrite(8, HIGH); //
analogWrite(9, HIGH); //
}
else if (num==8){
analogWrite(2, LOW); // Ground the segment a
analogWrite(3, LOW); // Ground the segment b
analogWrite(4, LOW); // Ground the segment c
analogWrite(5, LOW); // Ground the segment d
analogWrite(6, LOW); // Ground the segment e
analogWrite(7, LOW); // Ground the segment f
analogWrite(8, LOW); // Ground the segment g
analogWrite(9, HIGH); //
}
else if (num==9){
analogWrite(2, LOW); // Ground the segment a
analogWrite(3, LOW); // Ground the segment b
analogWrite(4, LOW); // Ground the segment c
analogWrite(5, HIGH); //
analogWrite(6, LOW); // Ground the segment e
analogWrite(7, LOW); // Ground the segment f
analogWrite(8, LOW); // Ground the segment g
analogWrite(9, HIGH); //
}
else if (num==10){
analogWrite(2, HIGH); //
analogWrite(3, HIGH); //
analogWrite(4, HIGH); //
analogWrite(5, HIGH); //
analogWrite(6, HIGH); //
analogWrite(7, HIGH); //
analogWrite(8, HIGH); //
analogWrite(9, LOW); // Ground the segment DP
}
else if (num==11){
analogWrite(2, HIGH); //
analogWrite(3, HIGH); //
analogWrite(4, HIGH); //
analogWrite(5, HIGH); //
analogWrite(6, HIGH); //
analogWrite(7, HIGH); //
analogWrite(8, LOW); // Ground the segment for negative
analogWrite(9, HIGH); //
}
} //End Function List

int x = 3;
int y = 9;
writenum(x,y);

}

2

Replace this line:

void writenum(int digit, int num);

for:

void writenum(int digit, int num)

Can you see the difference?

3

That's not going to fix it.
You need to not embed a function inside another.

And code tags, yes, we really like the code tag habit.

4

This is true! The function writenum() is inside the loop().

Without the code brackets, the code looks so bad...

5

giova014:
This is true! The function writenum() is inside the loop().

Right, I was going to say then I get this error. While highlighting the last } in the code.

Boost_Final.ino: In function 'void loop()':
Boost_Final:188: error: expected ';' before '}' token
expected ';' before '}' token

Should I make my own loop to run my function?

6

Or am I incorrectly writing the function code?

void writenum(int digit, int num);
{

How do I address the digit and the num inside the coding of the function?

7

Take another look at reply 1.
Move void writenum(int digit, int num) either before or after void loop()--but not inside setup() or any other function.
See what happens and let us know.

regards,
Michael

8

This is your code, cleaned up:

int digit;
int num;

void setup() {
  for (byte n = 2; n <= 13; n++)
    pinMode (n, OUTPUT);
}

void loop() {
  int x = 3;
  int y = 9;
  writenum(x, y);
}

void writenum(int digit, int num) {
  switch (digit) {

    case 1:
      digitalWrite(10, HIGH); // Chooses digit ? and lights up what are grounded
      digitalWrite(11, LOW); // Chooses digit ? and lights up what are grounded
      digitalWrite(12, LOW); // Chooses digit ? and lights up what are grounded
      digitalWrite(13, LOW); // Chooses digit ? and lights up what are grounded
      break;

    case 2:
      digitalWrite(10, HIGH); // Chooses digit ? and lights up what are grounded
      digitalWrite(11, LOW); // Chooses digit ? and lights up what are grounded
      digitalWrite(12, LOW); // Chooses digit ? and lights up what are grounded
      digitalWrite(13, LOW); // Chooses digit ? and lights up what are grounded
      break;

    case 3:
      digitalWrite(10, HIGH); // Chooses digit ? and lights up what are grounded
      digitalWrite(11, LOW); // Chooses digit ? and lights up what are grounded
      digitalWrite(12, LOW); // Chooses digit ? and lights up what are grounded
      digitalWrite(13, LOW); // Chooses digit ? and lights up what are grounded
      break;

    case 4:
      digitalWrite(10, HIGH); // Chooses digit ? and lights up what are grounded
      digitalWrite(11, LOW); // Chooses digit ? and lights up what are grounded
      digitalWrite(12, LOW); // Chooses digit ? and lights up what are grounded
      digitalWrite(13, LOW); // Chooses digit ? and lights up what are grounded
      break;
  }

  switch (num) {
    case 0:
      digitalWrite(2, LOW); // Ground the segment a
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, LOW); // Ground the segment c
      digitalWrite(5, LOW); // Ground the segment d
      digitalWrite(6, LOW); // Ground the segment e
      digitalWrite(7, LOW); // Ground the segment f
      digitalWrite(8, HIGH); //
      digitalWrite(9, HIGH); //
      break;

    case 1:
      digitalWrite(2, LOW); // Ground the segment a
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, HIGH); //
      digitalWrite(5, HIGH); //
      digitalWrite(6, HIGH); //
      digitalWrite(7, HIGH); //
      digitalWrite(8, HIGH); //
      digitalWrite(9, HIGH); //
      break;

    case 2:
      digitalWrite(2, LOW); // Ground the segment a
      digitalWrite(3, HIGH); //
      digitalWrite(4, LOW); // Ground the segment c
      digitalWrite(5, LOW); // Ground the segment d
      digitalWrite(6, HIGH); //
      digitalWrite(7, LOW); // Ground the segment f
      digitalWrite(8, LOW); // Ground the segment g
      digitalWrite(9, HIGH); //
      break;

    case 3:
      digitalWrite(2, LOW); // Ground the segment a
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, LOW); // Ground the segment c
      digitalWrite(5, HIGH); //
      digitalWrite(6, HIGH); //
      digitalWrite(7, LOW); // Ground the segment f
      digitalWrite(8, LOW); // Ground the segment g
      digitalWrite(9, HIGH); //
      break;

    case 4:
      digitalWrite(2, LOW); // Ground the segment a
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, HIGH); //
      digitalWrite(5, HIGH); //
      digitalWrite(6, LOW); // Ground the segment e
      digitalWrite(7, HIGH); //
      digitalWrite(8, LOW); // Ground the segment g
      digitalWrite(9, HIGH); //
      break;

    case 5:
      digitalWrite(2, HIGH); //
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, LOW); // Ground the segment c
      digitalWrite(5, HIGH); //
      digitalWrite(6, LOW); // Ground the segment e
      digitalWrite(7, LOW); // Ground the segment f
      digitalWrite(8, LOW); // Ground the segment g
      digitalWrite(9, HIGH); //
      break;

    case 6:
      digitalWrite(2, HIGH); //
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, LOW); // Ground the segment c
      digitalWrite(5, LOW); // Ground the segment d
      digitalWrite(6, LOW); // Ground the segment e
      digitalWrite(7, LOW); // Ground the segment f
      digitalWrite(8, LOW); // Ground the segment g
      digitalWrite(9, LOW); // Ground the segment DP
      break;

    case 7:
      digitalWrite(2, LOW); // Ground the segment a
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, HIGH); //
      digitalWrite(5, HIGH); //
      digitalWrite(6, HIGH); //
      digitalWrite(7, LOW); // Ground the segment f
      digitalWrite(8, HIGH); //
      digitalWrite(9, HIGH); //
      break;

    case 8:
      digitalWrite(2, LOW); // Ground the segment a
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, LOW); // Ground the segment c
      digitalWrite(5, LOW); // Ground the segment d
      digitalWrite(6, LOW); // Ground the segment e
      digitalWrite(7, LOW); // Ground the segment f
      digitalWrite(8, LOW); // Ground the segment g
      digitalWrite(9, HIGH); //
      break;

    case 9:
      digitalWrite(2, LOW); // Ground the segment a
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, LOW); // Ground the segment c
      digitalWrite(5, HIGH); //
      digitalWrite(6, LOW); // Ground the segment e
      digitalWrite(7, LOW); // Ground the segment f
      digitalWrite(8, LOW); // Ground the segment g
      digitalWrite(9, HIGH); //
      break;

    case 10:
      digitalWrite(2, HIGH); //
      digitalWrite(3, HIGH); //
      digitalWrite(4, HIGH); //
      digitalWrite(5, HIGH); //
      digitalWrite(6, HIGH); //
      digitalWrite(7, HIGH); //
      digitalWrite(8, HIGH); //
      digitalWrite(9, LOW); // Ground the segment DP
      break;

    case 11:
      digitalWrite(2, HIGH); //
      digitalWrite(3, HIGH); //
      digitalWrite(4, HIGH); //
      digitalWrite(5, HIGH); //
      digitalWrite(6, HIGH); //
      digitalWrite(7, HIGH); //
      digitalWrite(8, LOW); // Ground the segment for negative
      digitalWrite(9, HIGH); //
      break;
  }
}

Use the switch() when comparing the same variable with multiple values.
Use digitalWrite() when writing HIGH and LOW values to a Digital Pin.

9

My next error is the following...

Boost_Final:185: error: expected constructor, destructor, or type conversion before '(' token
expected constructor, destructor, or type conversion before '(' token

Any ideas?

10

giova014:
This is your code, cleaned up:

int digit;

int num;

void setup() {
  for (byte n = 2; n <= 13; n++)
    pinMode (n, OUTPUT);
}

void loop() {
  int x = 3;
  int y = 9;
  writenum(x, y);
}

void writenum(int digit, int num) {
  switch (digit) {

case 1:
      digitalWrite(10, HIGH); // Chooses digit ? and lights up what are grounded
      digitalWrite(11, LOW); // Chooses digit ? and lights up what are grounded
      digitalWrite(12, LOW); // Chooses digit ? and lights up what are grounded
      digitalWrite(13, LOW); // Chooses digit ? and lights up what are grounded
      break;

case 2:
      digitalWrite(10, HIGH); // Chooses digit ? and lights up what are grounded
      digitalWrite(11, LOW); // Chooses digit ? and lights up what are grounded
      digitalWrite(12, LOW); // Chooses digit ? and lights up what are grounded
      digitalWrite(13, LOW); // Chooses digit ? and lights up what are grounded
      break;

case 3:
      digitalWrite(10, HIGH); // Chooses digit ? and lights up what are grounded
      digitalWrite(11, LOW); // Chooses digit ? and lights up what are grounded
      digitalWrite(12, LOW); // Chooses digit ? and lights up what are grounded
      digitalWrite(13, LOW); // Chooses digit ? and lights up what are grounded
      break;

case 4:
      digitalWrite(10, HIGH); // Chooses digit ? and lights up what are grounded
      digitalWrite(11, LOW); // Chooses digit ? and lights up what are grounded
      digitalWrite(12, LOW); // Chooses digit ? and lights up what are grounded
      digitalWrite(13, LOW); // Chooses digit ? and lights up what are grounded
      break;
  }

switch (num) {
    case 0:
      digitalWrite(2, LOW); // Ground the segment a
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, LOW); // Ground the segment c
      digitalWrite(5, LOW); // Ground the segment d
      digitalWrite(6, LOW); // Ground the segment e
      digitalWrite(7, LOW); // Ground the segment f
      digitalWrite(8, HIGH); //
      digitalWrite(9, HIGH); //
      break;

case 1:
      digitalWrite(2, LOW); // Ground the segment a
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, HIGH); //
      digitalWrite(5, HIGH); //
      digitalWrite(6, HIGH); //
      digitalWrite(7, HIGH); //
      digitalWrite(8, HIGH); //
      digitalWrite(9, HIGH); //
      break;

case 2:
      digitalWrite(2, LOW); // Ground the segment a
      digitalWrite(3, HIGH); //
      digitalWrite(4, LOW); // Ground the segment c
      digitalWrite(5, LOW); // Ground the segment d
      digitalWrite(6, HIGH); //
      digitalWrite(7, LOW); // Ground the segment f
      digitalWrite(8, LOW); // Ground the segment g
      digitalWrite(9, HIGH); //
      break;

case 3:
      digitalWrite(2, LOW); // Ground the segment a
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, LOW); // Ground the segment c
      digitalWrite(5, HIGH); //
      digitalWrite(6, HIGH); //
      digitalWrite(7, LOW); // Ground the segment f
      digitalWrite(8, LOW); // Ground the segment g
      digitalWrite(9, HIGH); //
      break;

case 4:
      digitalWrite(2, LOW); // Ground the segment a
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, HIGH); //
      digitalWrite(5, HIGH); //
      digitalWrite(6, LOW); // Ground the segment e
      digitalWrite(7, HIGH); //
      digitalWrite(8, LOW); // Ground the segment g
      digitalWrite(9, HIGH); //
      break;

case 5:
      digitalWrite(2, HIGH); //
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, LOW); // Ground the segment c
      digitalWrite(5, HIGH); //
      digitalWrite(6, LOW); // Ground the segment e
      digitalWrite(7, LOW); // Ground the segment f
      digitalWrite(8, LOW); // Ground the segment g
      digitalWrite(9, HIGH); //
      break;

case 6:
      digitalWrite(2, HIGH); //
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, LOW); // Ground the segment c
      digitalWrite(5, LOW); // Ground the segment d
      digitalWrite(6, LOW); // Ground the segment e
      digitalWrite(7, LOW); // Ground the segment f
      digitalWrite(8, LOW); // Ground the segment g
      digitalWrite(9, LOW); // Ground the segment DP
      break;

case 7:
      digitalWrite(2, LOW); // Ground the segment a
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, HIGH); //
      digitalWrite(5, HIGH); //
      digitalWrite(6, HIGH); //
      digitalWrite(7, LOW); // Ground the segment f
      digitalWrite(8, HIGH); //
      digitalWrite(9, HIGH); //
      break;

case 8:
      digitalWrite(2, LOW); // Ground the segment a
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, LOW); // Ground the segment c
      digitalWrite(5, LOW); // Ground the segment d
      digitalWrite(6, LOW); // Ground the segment e
      digitalWrite(7, LOW); // Ground the segment f
      digitalWrite(8, LOW); // Ground the segment g
      digitalWrite(9, HIGH); //
      break;

case 9:
      digitalWrite(2, LOW); // Ground the segment a
      digitalWrite(3, LOW); // Ground the segment b
      digitalWrite(4, LOW); // Ground the segment c
      digitalWrite(5, HIGH); //
      digitalWrite(6, LOW); // Ground the segment e
      digitalWrite(7, LOW); // Ground the segment f
      digitalWrite(8, LOW); // Ground the segment g
      digitalWrite(9, HIGH); //
      break;

case 10:
      digitalWrite(2, HIGH); //
      digitalWrite(3, HIGH); //
      digitalWrite(4, HIGH); //
      digitalWrite(5, HIGH); //
      digitalWrite(6, HIGH); //
      digitalWrite(7, HIGH); //
      digitalWrite(8, HIGH); //
      digitalWrite(9, LOW); // Ground the segment DP
      break;

case 11:
      digitalWrite(2, HIGH); //
      digitalWrite(3, HIGH); //
      digitalWrite(4, HIGH); //
      digitalWrite(5, HIGH); //
      digitalWrite(6, HIGH); //
      digitalWrite(7, HIGH); //
      digitalWrite(8, LOW); // Ground the segment for negative
      digitalWrite(9, HIGH); //
      break;
  }
}




Use the switch() when comparing the same variable with multiple values.
Use digitalWrite() when writing HIGH and LOW values to a Digital Pin.

Thanks!!!!!!!!!!!!!!!!!!!!!!! I wasn't quite sure how to use the Switch function... I see now!! I really appreciate it!!