Hi, This is my code and I keep getting the error message
" 'LiquidCrystal' does not name a type "
Can anyone help me with this.
Thanks, CoreyAlan15
/* 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 example code is in the public domain.
*/
// this constant won't change. It's the pin number
// of the sensor's output:
const int pingPin = 7;
__________________________________________________
LiquidCrystal lcd(12, 11, 10, 5, 4, 3, 2);
int backLight = 13; // pin 13 will control the backlight
void setup() {
___________________________________________________
// set up the LCD's number of columns and rows:
lcd.begin(20, 4);
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();
//__________________________This is my part of the code.
if (Serial.available()) {
delay(100);
lcd.clear();
while (Serial.available() > 0) {
lcd.write(Serial.read());
//_____________________________
delay(1000)
}
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;
}
I just made a similar sketch myself, and ran across a odd error…
and this is the error code I get:
sketch_feb16a.cpp: In function ‘void loop()’:
sketch_feb16a:69: error: ‘lcd’ was not declared in this scope
/*stripped down code to read distance for Ping)) Ultrasonic
and display output on both the serial console, and
on the 1602 LCD display.
The circuit:
The Ping)) SIG to Digital Pin 7
The VDD to +5 in parallel with the LCD Pin 2
The GND to common GND bus (to pins 1 & 5 of LCD, and the Contrast
POT.)
* LCD RS pin to digital pin 12
* LCD Enable pin to digital pin 11
* LCD D4 pin to digital pin 5
* LCD D5 pin to digital pin 4
* LCD D6 pin to digital pin 3
* LCD D7 pin to digital pin 2
* LCD R/W pin to ground
* 10K resistor:
* ends to +5V and ground
* wiper to LCD VO pin (pin 3)
*/
// this constant won't change. It's the pin number
// of the sensor's output:
// include the library code:
#include <LiquidCrystal.h>
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; // wanting just inches, no 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);
Serial.print(inches);
Serial.print("in, ");
Serial.println();
// set the cursor to column 0, line 1
// (note: line 1 is the second row, since counting begins with 0):
lcd.setCursor(0, 1);
// print the number of inches:
lcd.print(inches);
lcd.print(" In.");
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;
}
So, what is wrong with this picture? Why is it trying to declare the lcd.setCursor function, as a variable?
Once I inserted it in the right place (I had it under the void setup(), which was the wrong place.), it compiled right, and works.
Okay, since the LCD is occupying 6 wires, the ping occupying 1, leaves me few usable digital pins for the robot project I’m working on… But, so-far, It’s just test-bed stuff. I have a MEGA-2560 waiting once things are finalized.
Thanks for pointing it out… Typical newbie C programmer.
liudr:
You're welcome. The 10 is RW, which you don't have to use and save one pin.
Ah, Okay.. The usual circuit I've been finding, has the r/w pin GND'ed, so that explains it.
Also noticed I forgot the lcd.begin(16,2) statement :( ... finally got everything working, and fine-tuned to display feet & inches.
Wish I could find it again, I had a nice 16 X 3 LCD I pulled from an old dead printer.. Finally finding datasheets to all kinds of devices I used
to tinker with long ago.. One tough one, is a 2.4Ghz RF TX/RX module, MAR105C.. finding it in a lot of cheap wireless game controllers. Finding some source pages, but no readable documentation..
OOPS! I knew I forgot something, But it also wasn’t working when I realized I inserted it in the wrong place too…