Go Down

Topic: PING))) LCD (Read 2 times) previous topic - next topic

tlavite

I am having trouble making a PING))) ultrasonic sensor display distance readout on an LCD. I need help with the code. Please
Tyler LaVite
tlavite@gmail.com

CaptainObvious

Well, let's start off by seeing your current code..

You should be able to combine the two examples, LiquidCrystal and the Ping sensor fairly easily.

tlavite

#2
Oct 06, 2009, 08:48 am Last Edit: Oct 06, 2009, 09:13 am by tyler_lavite Reason: 1
What exactly would i have to change? i have been trying and trying to get it to work lol i such with this code so far.

EDIT* the code i have so far

#include <LiquidCrystal.h>

// LiquidCrystal display with:
// rs on pin 12
// rw on pin 11
// enable on pin 10
// d4, d5, d6, d7 on pins 5, 4, 3, 2
LiquidCrystal lcd(12, 11, 10, 5, 4, 3, 2);

const int pingPin = 7;
void setup() {
 
  Serial.begin(9600);
  lcd.print("in, ");
}
void loop()
{

  long duration, inches, cm;
 
  pinMode(pingPin, OUTPUT);
  digitalWrite(pingPin, LOW);
  delayMicroseconds(2);
  digitalWrite(pingPin, HIGH);
  delayMicroseconds(5);
  digitalWrite(pingPin, LOW);

  pinMode(pingPin, INPUT);
  duration = pulseIn(pingPin, HIGH);

  inches = microsecondsToInches(duration);
  cm = microsecondsToCentimeters(duration);
  Serial.print(inches);
  Serial.print("in, ");
  Serial.print(cm);
  Serial.print("cm");
  Serial.println();
  delay(100);
}
long microsecondsToInches(long microseconds)
{
 
  return microseconds / 74 / 2;
}
long microsecondsToCentimeters(long microseconds)
{
 
  return microseconds / 29 / 2;
}
Tyler LaVite
tlavite@gmail.com

CaptainObvious

#3
Oct 06, 2009, 09:11 am Last Edit: Oct 06, 2009, 09:13 am by thoed Reason: 1
I thought ping sensors used 1 pin for input and output, I only see input here.

(btw, use the Code key (#) above, when you're posting code, makes it much easier to read:))

The code looks okay for the most part, haven't used the 4bitLCD, usually use liquid crystal, but something I'm curious about
Code: [Select]

// PRINT USING INCHES
  lcd.printIn(itoa(val, buf, 10));
  lcd.printIn(" in / ");
  // PRINT USING CENTIMETERS
  lcd.printIn(itoa(val * 2.54, buf, 10));
  lcd.printIn(" cm");

Not sure if the first one is really inches, but if so.. you're saying that a CM is equal to 2.54 times the size of an inch. (Maybe your comments are backwards?:X)


But you never stated WHAT your problems are...
are you receiving some data, but it doesn't make sense?
are you not receiving any data?
which ping sensor is it? Some have 2 pins for the input and output, but others just use one. Both can work with the Arduino, but have to adjust your code.. and the code you're using suggests, uhh.. that your ping sensor is working all the time.

Take a look at the ping example with the IDE. You first need to put the output pin HIGH, then read the input. I'm not seeing where you put the sensor high for the reading. Your code would *probably* work with some analog sensor, such as an LDR, potentiometer, sharp sensor.. etc.

Code: [Select]
/* Ping))) Sensor
 
  This sketch reads a PING))) ultrasonic rangefinder and returns the
  distance to the closest object in range. To do this, it sends a pulse
  to the sensor to initiate a reading, then listens for a pulse
  to return.  The length of the returning pulse is proportional to
  the distance of the object from the sensor.
   
  The circuit:
     * +V connection of the PING))) attached to +5V
     * GND connection of the PING))) attached to ground
     * SIG connection of the PING))) attached to digital pin 7

  http://www.arduino.cc/en/Tutorial/Ping
 
  created 3 Nov 2008
  by David A. Mellis
  modified 30 Jun 2009
  by Tom Igoe

*/

// this constant won't change.  It's the pin number
// of the sensor's output:
const int pingPin = 7;

void setup() {
 // initialize serial communication:
 Serial.begin(9600);
}

void loop()
{
 // establish variables for duration of the ping,
 // and the distance result in inches and centimeters:
 long duration, inches, cm;

 // The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
 // Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
 pinMode(pingPin, OUTPUT);
 digitalWrite(pingPin, LOW);
 delayMicroseconds(2);
 digitalWrite(pingPin, HIGH);
 delayMicroseconds(5);
 digitalWrite(pingPin, LOW);

 // The same pin is used to read the signal from the PING))): a HIGH
 // pulse whose duration is the time (in microseconds) from the sending
 // of the ping to the reception of its echo off of an object.
 pinMode(pingPin, INPUT);
 duration = pulseIn(pingPin, HIGH);

 // convert the time into a distance
 inches = microsecondsToInches(duration);
 cm = microsecondsToCentimeters(duration);
 
 Serial.print(inches);
 Serial.print("in, ");
 Serial.print(cm);
 Serial.print("cm");
 Serial.println();
 
 delay(100);
}

long microsecondsToInches(long microseconds)
{
 // According to Parallax's datasheet for the PING))), there are
 // 73.746 microseconds per inch (i.e. sound travels at 1130 feet per
 // second).  This gives the distance travelled by the ping, outbound
 // and return, so we divide by 2 to get the distance of the obstacle.
 // See: http://www.parallax.com/dl/docs/prod/acc/28015-PING-v1.3.pdf
 return microseconds / 74 / 2;
}

long microsecondsToCentimeters(long microseconds)
{
 // The speed of sound is 340 m/s or 29 microseconds per centimeter.
 // The ping travels out and back, so to find the distance of the
 // object we take half of the distance travelled.
 return microseconds / 29 / 2;
}

Notice how the code puts the pin to an OUTPUT first, then pings, then puts it back into an INPUT.

tlavite

well that code i got off another site... its not for the parallax ping sensor.. this is what i have come up with

Code: [Select]
#include <LiquidCrystal.h>

// LiquidCrystal display with:
// rs on pin 12
// rw on pin 11
// enable on pin 10
// d4, d5, d6, d7 on pins 5, 4, 3, 2
LiquidCrystal lcd(12, 11, 10, 5, 4, 3, 2);

const int pingPin = 7;
void setup() {
 
  Serial.begin(9600);
  lcd.print("in, ");
}
void loop()
{

  long duration, inches, cm;
 
  pinMode(pingPin, OUTPUT);
  digitalWrite(pingPin, LOW);
  delayMicroseconds(2);
  digitalWrite(pingPin, HIGH);
  delayMicroseconds(5);
  digitalWrite(pingPin, LOW);

  pinMode(pingPin, INPUT);
  duration = pulseIn(pingPin, HIGH);

  inches = microsecondsToInches(duration);
  cm = microsecondsToCentimeters(duration);
  Serial.print(inches);
  Serial.print("in, ");
  Serial.print(cm);
  Serial.print("cm");
  Serial.println();
  delay(100);
}
long microsecondsToInches(long microseconds)
{
 
  return microseconds / 74 / 2;
}
long microsecondsToCentimeters(long microseconds)
{
 
  return microseconds / 29 / 2;
}
Tyler LaVite
tlavite@gmail.com

Go Up