Error compiling for arduino nano board.

Projects Programming
1

Hello, i am trying to make an infrared based thermometer, but i am getting an error message that i don't know the meaning of since i am new to arduino. If you can help me i would be thankful!

#include <i2cmaster.h>
#include <LiquidCrystal.h>


LiquidCrystal lcd (8, 9, 4, 5, 6, 7);

int address = 0xb4; // Sensor address MLX90614
int data1 = 0; // The second byte of data
int data2 = 0; // The first byte of data
double temperature = 0; // Variable holding the temperature
 
void setup() {
  pinMode(10,OUTPUT);
  pinMode(11,OUTPUT);
  
  i2c_init (); // Initialization of the I2C bus
  lcd.begin (16, 2); // Initialize the display
}
void loop() {
  digitalWrite(10,HIGH); //Turns on the Laser Pointer for accurate aiming
  
  i2c_start_wait (address + I2C_WRITE); // Start I2C communication in write mode
  i2c_write (0x07); // Write the value 0x07 (select the register Tobj1)
  i2c_rep_start (address + I2C_READ); // Restart I2C communication at the read address
  data1 = i2c_readAck (); // Read the first byte of data
  data2 = i2c_readAck (); // Read the second byte of data
  i2c_stop (); // End of I2C transmission
  
  
  temperature = (double) (((data1 & 0x007F) << 8) + data2); // Create a 16-bit variable consisting of two one-byte variables
  temperature = temperature * 0.02; // To change from the value read to Temperature in Kelvin
  
  temperature = temperature - 273.15; // Conversion to Celsius degrees
  
  lcd.setCursor (0,0); // Display (first LCD line)
  lcd.print ("Object =");
  lcd.print (temperature);
  lcd.print ("");
  lcd.write (0xDF); // Degree sign
  lcd.print ("C");
  delay (200);
  if(temperature > 38) //Turns on the red LED if the temperature read is more than 38 degrees celsius
  digitalWrite(11,HIGH);
  else digitalWrite(11,LOW);
  delay (200);
}

This is the error message:
Arduino: 1.8.12 (Windows 10), Board: "Arduino Nano, ATmega328P"

C:\Users\JADBAA~1\AppData\Local\Temp\ccp5fJrZ.ltrans0.ltrans.o: In function `setup':

C:\Users\Jad Baalbaki\Downloads\Laser_Temp_Gun/Laser_Temp_Gun.ino:16: undefined reference to `i2c_init()'

C:\Users\JADBAA~1\AppData\Local\Temp\ccp5fJrZ.ltrans0.ltrans.o: In function `loop':

C:\Users\Jad Baalbaki\Downloads\Laser_Temp_Gun/Laser_Temp_Gun.ino:22: undefined reference to `i2c_start_wait(unsigned char)'

C:\Users\Jad Baalbaki\Downloads\Laser_Temp_Gun/Laser_Temp_Gun.ino:23: undefined reference to `i2c_write(unsigned char)'

C:\Users\Jad Baalbaki\Downloads\Laser_Temp_Gun/Laser_Temp_Gun.ino:24: undefined reference to `i2c_rep_start(unsigned char)'

C:\Users\Jad Baalbaki\Downloads\Laser_Temp_Gun/Laser_Temp_Gun.ino:25: undefined reference to `i2c_readAck()'

C:\Users\Jad Baalbaki\Downloads\Laser_Temp_Gun/Laser_Temp_Gun.ino:26: undefined reference to `i2c_readAck()'

C:\Users\Jad Baalbaki\Downloads\Laser_Temp_Gun/Laser_Temp_Gun.ino:27: undefined reference to `i2c_stop()'

collect2.exe: error: ld returned 1 exit status

exit status 1
Error compiling for board Arduino Nano.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

2

What's wrong with the Wire library?

3

you suggest i use the wire library instead?

4

So i used the wire library, but i am not sure if the things i changed are correct. can you give it a quick look?

#include <Wire.h>
#include <LiquidCrystal.h>


LiquidCrystal lcd (8, 9, 4, 5, 6, 7);

int address = 0xb4; // Sensor address MLX90614
int data1 = 0; // The second byte of data
int data2 = 0; // The first byte of data
double temperature = 0; // Variable holding the temperature
 
void setup() {
  pinMode(10,OUTPUT);
  pinMode(11,OUTPUT);
  
  Wire.begin (); // Initialization of the I2C bus
  lcd.begin (16, 2); // Initialize the display
}
void loop() {
  digitalWrite(10,HIGH); //Turns on the Laser Pointer for accurate aiming
  
  Wire.beginTransmission (address); // Start I2C communication in write mode
  Wire.write(0x07); // Write the value 0x07 (select the register Tobj1)
 Wire.requestFrom(address,8); // Restart I2C communication at the read address
  data1 = Wire.read(); // Read the first byte of data
  data2 = Wire.read(); // Read the second byte of data
  Wire.endTransmission(); // End of I2C transmission
  
  
  temperature = (double) (((data1 & 0x007F) << 8) + data2); // Create a 16-bit variable consisting of two one-byte variables
  temperature = temperature * 0.02; // To change from the value read to Temperature in Kelvin
  
  temperature = temperature - 273.15; // Conversion to Celsius degrees
  
  lcd.setCursor (0,0); // Display (first LCD line)
  lcd.print ("Object =");
  lcd.print (temperature);
  lcd.print ("");
  lcd.write (0xDF); // Degree sign
  lcd.print ("C");
  delay (200);
  if(temperature > 38) //Turns on the red LED if the temperature read is more than 38 degrees celsius
  digitalWrite(11,HIGH);
  else digitalWrite(11,LOW);
  delay (200);
}
5

Take a look at the examples that come with the Wire library. They are done a bit different than your code.
If you want to write to the device, you do a beginTransmission(), a series of write()'s and then endTransmission().

If you want to read something, you just do requestFrom().