Day 13: 2-Dimensional Arrays || I2C Sensors

Lab: I2C Temperature Sensor

Figure 1.1
Serial monitor displaying temperature data

Code

//Reads Temp from I2C temperature sensor and prints it on the serial port

//Include Wire I2C library

#include <Wire.h>

int temp_address = 72; //1001000 written as decimal number

void setup()

{

//Start serial communication at 9600 baud

Serial.begin(9600);

//Create a Wire object

Wire.begin();

}

void loop()

{

//Send a request

//Start talking to the device at the specified address

Wire.beginTransmission(temp_address);

//Send a bit asking for register zero, the data register

Wire.write(0);

//Complete Transmission

Wire.endTransmission();

//Read the temperature from the device

//Request 1 Byte from the specified address

Wire.requestFrom(temp_address, 1);

//Wait for response

while(Wire.available() == 0);

//Get the temp and read it into a variable

int c = Wire.read();

//Do some math to convert the Celsius to Fahrenheit

int f = round(c*9.0/5.0 +32.0);

//Send the temperature in degrees C and F to the serial monitor

Serial.print(c);

Serial.print("C ");

Serial.print(f);

Serial.println("F");

delay(500);

}

Software

Arrays are passed directly into the function as an address rather than as a copy, similarly to pointers.
To define 2D array, number of rows and columns is specified in declaration statement.
int x[4][3]; indicates an array with 4 rows and 3 columns.
can also be initialized with declaration statement

Computations and Output

Homework

//Reads Temp from I2C temperature sensor and prints it on the serial port

//Include Wire I2C library

#include <Wire.h>

#include <LiquidCrystal.h>

int temp_address = 72; //1001000 written as decimal number

int btn=A0;

int tempMode=0;

int lastVal=0;

void setup()

{

//Set up LCD number of column and rows

lcd.begin(16,2);

lcd.print("Day 13 Homework");

//Start serial communication at 9600 baud

Serial.begin(9600);

//Create a Wire object

Wire.begin();

}

void currentMode()

{

int sensorVal=analogRead(btn);

if(sensorVal==479 && lastVal!=1)

{

tempMode=1;

lastVal=1;

}

if(sensorVal==0 && lastVal!=2)

{

tempMode=2;

lastVal=2;

}