Problem for configure the LM92 temp Sensor using I2C.

Other Hardware Sensors
1

Hi everyone :),

I bought a LM92 temp sensor and I have done my first tests. Read the temperature values ??was not a problem but I want to configure the interrupt register to generate an alert when arrive at a specific temperature.

Datasheet: http://www.ti.com/lit/ds/symlink/lm92.pdf

My problem is that I don't know how send data because this is 16 bits. I put my code, I set alarm for low temperature when it arrives at 32 °, for example turn on a led.

Reading LM92.

#include <Wire.h>

char lm92addr = 0x48;   //A1 and A0 to GND  #1001000

int val = 0x1900;
char buffer[2];
int tempcode;
float temp;

void setup()
{
 Serial.begin(9600);
 Wire.begin();
// Pag. 13 on Datasheet, the register is 16bits 
// (temperature data is bit3 - bit15)
 Wire.beginTransmission(lm92addr);
 Wire.write(0x04);     // Register address for configure T_LOW
 Wire.write(0x18);     // set value: 0001100000000000 T-Low 30ºC first 8Bit
 Wire.write(0x00);     // second 8Bit 
 // T_High
 Wire.write(0x05);     // Register address for configure T_High
 Wire.write(0x19);     // set value: 0001100110000000 T_High 33ºC
 Wire.write(0x80);
 Wire.endTransmission();
}

void loop()
{
 Wire.requestFrom(lm92addr,2); // Se solicitan los dos Bytes
  if (Wire.available()) 
  {
   for(int i=0; i<2; i++) 
   {
    buffer[i]= Wire.read();
   }
   tempcode= ((buffer[0] << 8) + buffer[1]) >>3;
   temp = tempcode * 0.0625;
   Serial.print("t = "); 
   Serial.print(temp);
   Serial.print(" C");
   Serial.println();
  }
delay(500);
}

I'm not sure :roll_eyes: if it is correct divided my chain into two 8-bit, but if I send Wire.write(0x1800); seems not to work. What is the correct way to send the string or write on the sensor.

Sorry for my english, a greeting and thank you very much. :smiley: