Hi all
Not sure why i can only post the this area but here goes
I am not sure why I get this message
'readPing' was not declared in this scope
see attached code. I have used this code before.
Any help would be great, I am still new to this.
//Start for Skid Steer Tank project
#include <Wire.h>
#include <Adafruit_MotorShield.h>
#include <NewPing.h>
#include <Servo.h>
#define TRIG_PIN A1
#define ECHO_PIN A2
#define MAX_DISTANCE 100
const int FLIGHT_Pin = A3;
const int RLIGHT_Pin = A4;
const int LLIGHT_Pin = A5;
Adafruit_MotorShield AFMS = Adafruit_MotorShield(); // Create the Motor shield object with the default I2C address
Adafruit_DCMotor *myRightMotor = AFMS.getMotor(1); // Select which 'port' M1, M2, M3 or M4. In this case, M1
Adafruit_DCMotor *myLeftMotor = AFMS.getMotor(4);
NewPing sonar(TRIG_PIN, ECHO_PIN, MAX_DISTANCE);
Servo myservo;
int distance = 200;
// int readPing();
void setup() {
AFMS.begin(); // create with the default frequency 1.6KHz
myservo.attach(10);
myservo.write(115);
delay(2000);
distance = readPing();
// delay(100);
// distance = readPing();
// delay(100);
// distance = readPing();
// delay(100);
// distance = readPing();
// delay(100);
}
void loop() {
myRightMotor->run(FORWARD);
{
myRightMotor->setSpeed(200);
delay(1000);
}
myRightMotor->run(BACKWARD);
{
myRightMotor->setSpeed(150);
delay(1000);
}
myRightMotor->run(RELEASE);
{
delay(1000);
}
// Left Motor Test
myLeftMotor->run(FORWARD);
{
myLeftMotor->setSpeed(200);
delay(1000);
}
myLeftMotor->run(BACKWARD);
{
myLeftMotor->setSpeed(150);
delay(1000);
}
myLeftMotor->run(RELEASE);
{
delay(1000);
}
}
There's a forward definition of the function here, but it's commented out. If you uncomment that, it will fix the error you have, but create another error because you will have a forward definition of a function but no full definition of that function.
I guess you lost part of it when you copied it over to this code.
Ok
now have uncommented " int readPing(); " above Setup and now get this error
" C:\Users\User\AppData\Local\Temp\ccG2ZC0q.ltrans0.ltrans.o: In function setup': C:\Users\User\Documents\Arduino\Skid_Steer_Tank_Start_2/Skid_Steer_Tank_Start_2.ino:34: undefined reference to readPing()'
collect2.exe: error: ld returned 1 exit status
Multiple libraries were found for "Servo.h"
Used: C:\Users\User\Documents\Arduino\libraries\Servo
Not used: C:\Users\User\AppData\Local\Arduino15\libraries\Servo
exit status 1
Compilation error: exit status 1 "
How do I fix " undifined reference to "readPing"
Sorry I am still trying to learn this coding.
What model Arduino are you using?
What do you expect;
readPing();
to do.
This is the NewPing example,
// ---------------------------------------------------------------------------
// Example NewPing library sketch that does a ping about 20 times per second.
// ---------------------------------------------------------------------------
#include <NewPing.h>
#define TRIGGER_PIN 12 // Arduino pin tied to trigger pin on the ultrasonic sensor.
#define ECHO_PIN 11 // Arduino pin tied to echo pin on the ultrasonic sensor.
#define MAX_DISTANCE 200 // Maximum distance we want to ping for (in centimeters). Maximum sensor distance is rated at 400-500cm.
NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE); // NewPing setup of pins and maximum distance.
void setup() {
Serial.begin(115200); // Open serial monitor at 115200 baud to see ping results.
}
void loop() {
delay(50); // Wait 50ms between pings (about 20 pings/sec). 29ms should be the shortest delay between pings.
Serial.print("Ping: ");
Serial.print(sonar.ping_cm()); // Send ping, get distance in cm and print result (0 = outside set distance range)
Serial.println("cm");
}
Hi Tom
this bit of code was used in an " Obstacle Avoiding Vehicle " I built and just copied all it over to the new code
I can not see any reference to " readPing " except in void Setup().
I am trying to read the distance info from the HC-SR04
I can still compile that code.
My IDE version is 2.3.2
hope this helps
Ian
This is the original code but was using an old V1 Motor board
This was for a 4 motor car I am now trying to build a 2 motor skidsteer tank.
This code still compiles on all my computers.
I can not see any other references to " readPing " anywhere.
Any more ideas
Thank you
#include <AFMotor.h>
#include <NewPing.h>
#include <Servo.h>
#define TRIG_PIN A1
#define ECHO_PIN A2
#define MAX_DISTANCE 100
#define MAX_SPEED 150 // sets speed of DC motors
#define RMAX_SPEED 150 // try to set Bacward speed higher to make it move back further
#define MAX_SPEED_OFFSET 20
const int FLIGHT_Pin = A3;
const int RLIGHT_Pin = A4;
const int LLIGHT_Pin = A5;
NewPing sonar(TRIG_PIN, ECHO_PIN, MAX_DISTANCE);
AF_DCMotor motor1(1, MOTOR12_64KHZ);
AF_DCMotor motor2(2, MOTOR12_64KHZ);
AF_DCMotor motor3(3, MOTOR34_64KHZ);
AF_DCMotor motor4(4, MOTOR34_64KHZ);
Servo myservo;
boolean goesForward=false;
int distance = 200; // change from 100 to 200 did not see much difference
int speedSet = 0;
void setup() {
pinMode(FLIGHT_Pin, OUTPUT);
pinMode (RLIGHT_Pin, OUTPUT);
pinMode(LLIGHT_Pin, OUTPUT);
myservo.attach(10);
myservo.write(115);
delay(2000);
distance = readPing();
delay(100);
distance = readPing();
delay(100);
distance = readPing();
delay(100);
distance = readPing();
delay(100);
}
void loop() {
int distanceR = 0;
int distanceL = 0;
delay(40);
if(distance<=50) // change from 25 to 50 this makes it stop further away
{
moveStop();
delay(100);
moveBackward();
delay(400); // increase from 200 to 400 to try and get to move back further
moveStop();
delay(200);
distanceR = lookRight();
delay(200);
distanceL = lookLeft();
delay(200);
if(distanceR>=distanceL)
{
turnRight();
moveStop();
if(distanceR>=distanceL) // second look Rt makes it turn 180
{
turnRight();
moveStop();
}
}
else
{
turnLeft();
moveStop();
}
if(distanceL>=distanceR) // added second ckeck on turn Left
{
turnLeft();
moveStop();
}
}
else
{
moveForward();
}
distance = readPing();
}
int lookRight()
{
myservo.write(50);
delay(500);
int distance = readPing();
delay(100);
myservo.write(115);
return distance;
}
int lookLeft()
{
myservo.write(170);
delay(500);
int distance = readPing();
delay(100);
myservo.write(115);
return distance;
delay(100);
}
int readPing() {
delay(100);
int cm = sonar.ping_cm();
if(cm==0)
{
cm = 250;
}
return cm;
}
void moveStop() {
motor1.run(RELEASE);
motor2.run(RELEASE);
motor3.run(RELEASE);
motor4.run(RELEASE);
}
void moveForward() {
if(!goesForward)
{
goesForward=true;
digitalWrite(A3, HIGH); // Turn ON Forward LED
motor1.run(FORWARD);
motor2.run(FORWARD);
motor3.run(FORWARD);
motor4.run(FORWARD);
for (speedSet = 0; speedSet < MAX_SPEED; speedSet +=2) // slowly bring the speed up to avoid loading down the batteries too quickly
{
motor1.setSpeed(speedSet);
motor2.setSpeed(speedSet);
motor3.setSpeed(speedSet);
motor4.setSpeed(speedSet);
delay(5);
// digitalWrite(A3, LOW); // Turn OFF Forward LED
}
}
}
void moveBackward() {
goesForward=false;
motor1.run(BACKWARD);
motor2.run(BACKWARD);
motor3.run(BACKWARD);
motor4.run(BACKWARD);
for (speedSet = 0; speedSet < RMAX_SPEED; speedSet +=2) // Useing RMAX_SPEED slowly bring the speed up to avoid loading down the batteries too quickly works better
{
motor1.setSpeed(speedSet);
motor2.setSpeed(speedSet);
motor3.setSpeed(speedSet);
motor4.setSpeed(speedSet);
delay(5);
}
}
void turnRight() {
digitalWrite(A3, LOW);
digitalWrite(A4, HIGH); // Turn ON Right LED
motor1.run(FORWARD); // CHANGED TO FORWARD FOR STEERING TEST
motor2.run(BACKWARD);
motor3.run(FORWARD); // changed to FORWARD to try and make it move better
motor4.run(BACKWARD);
delay(500);
motor1.run(FORWARD);
motor2.run(FORWARD);
motor3.run(FORWARD);
motor4.run(FORWARD);
digitalWrite(A4, LOW); // Turn OFF Right LED
}
void turnLeft() {
digitalWrite(A3, LOW);
digitalWrite(A5, HIGH); // turn ON Left LED
motor1.run(BACKWARD); // CHANGED TO BACKWARD FOR STEERING TEST
motor2.run(FORWARD);
motor3.run(BACKWARD); // changed to BACKWARD to try and make it move better
motor4.run(FORWARD);
delay(500);
motor1.run(FORWARD);
motor2.run(FORWARD);
motor3.run(FORWARD);
motor4.run(FORWARD);
digitalWrite(A5, LOW); // turn OFF Left LED
}
The weird thing about coding is that it is almost impossible to really teach like that. You only really learn it by doing it. Having someone to guide you in that journey is helpful. But nobody can give you a class that you can walk away from and suddenly be able to write code.
Learning to code is about learning to think in small individual steps. It's about learning to break things down into repetitive units. It's about being able to identify the mathematical models behind everyday events. It's about being able to describe things without ambiguity because computers are pretty stupid.
The very least of it is commands and syntax. If you know the things I just mentioned, then syntax and commands are something you can just google.
