I'm using Tinkercad, and since it's my first time programming an LCD I just copied the procedure to connect the pins and make it work.
The thing is that it just lights up without displaying anything, I tried both wiring and unwiring the R/W pin but that doesn't work either, nothing will be displayed.
What did I miss? The other functions of the code works normally.
Image of the circuit:
This is the code:
#include <LiquidCrystal.h>
const int pin = 0; // analog pin
float celsius = 0, farhenheit =0; // temperature variables
float millivolts; //Millivolts from the sensor
int sensor;
const int G_LED = 13;
const int Y_LED = 12;
LiquidCrystal lcd(10, 9, 5, 4, 3, 2); // Building the LCD
void setup() {
lcd.begin(16,2);
lcd.clear();
lcd.setCursor(0,0);
lcd.print("C="); // "C=", "F=" and "mV" should be printed
lcd.setCursor(0, 1); // on the LCD in a column
lcd.print("F=");
lcd.setCursor(0, 2);
lcd.print("mV=");
pinMode(G_LED, OUTPUT);
pinMode(Y_LED, OUTPUT);
Serial.begin(9600);
}
void loop() {
sensor = analogRead(pin); // Reading the value from the LM35 sensor using the A0 ingress
millivolts = (sensor / 1023.0) * 5000; // Converting the value in a number that indicates the millivolts
celsius = ((sensor * 0.00488) - 0.5) / 0.01; // Celsius value (10 mV for each degree, 0°=500mV)
farhenheit = celsius * 1.8 + 32; // Fahrenheit value
lcd.setCursor(4, 2); // Set the cursor at the right of "mV="
lcd.print(millivolts); // Print the mV value
lcd.setCursor(4, 0); // Same here for °C and °F
lcd.print(celsius);
lcd.setCursor(4, 1);
Serial.print(farhenheit);
if (millivolts < 700) { // Green LED is on when the temperature is under or equal to 20°
// if (celsius < 20) { // Alternative
analogWrite(G_LED, 255);
analogWrite(Y_LED, 0); }
else {
analogWrite(G_LED, 0);
analogWrite(Y_LED, 255); // Yellow LED is on when the temperature is above of 20°C
}
delay(1000);
}
Fix - I could not find the error, but I suspect it was due to the strange layout of the connections. You also tried to set the cursor to line 3, but the LCD you were using did not have 3 lines, it was a 16x2 LCD
.
What I Did - So what I did was I re-did the entire project, I linked up a new LCD, this time with a digital contrast so that it could be dynamically changed. I also made sure to include the sensor you used in your last project. Over-all the project is an Arduino controlling an LCD and outputting the temperature in Fahrenheit and millivolts.
Here is the project link (Tinkercad).
Code:
#include <LiquidCrystal.h>
// Adds the liquid crystal lib
int contrast = 40; // Set the contrast of the LCD
LiquidCrystal lcd (12, 11, 5, 4, 3, 2); // Instantiate the LCD
float fahrenheit;
float millivolts;
void setup ()
{
analogWrite(6, contrast); // Wrjte the contrast to the LCD
lcd.begin(16, 2); // Init the LCD
}
void loop ()
{
int sensor = analogRead(0);
millivolts = (sensor/1023.0)*5000;
fahrenheit = (((sensor*0.00488)-0.5)/0.01)*1.8+32;
lcd.setCursor(0, 0);
lcd.print("Temp(F):");
lcd.setCursor(11, 0);
lcd.print(fahrenheit);
lcd.setCursor(0, 1);
lcd.print("Volts(mV):");
lcd.setCursor(12, 1);
lcd.print(millivolts);
}