The TMP75 and TMP175 devices are digital temperature sensors ideal for NTC and PTC thermistor replacement. The devices offer a typical accuracy of ±1°C without requiring calibration or external component signal conditioning. IC temperature sensors are highly linear and do not require complex calculations or look-up tables to derive the temperature. The on-chip 12-bit ADC offers resolutions down to 0.0625°C. The devices are available in the industry standard LM75 SOIC-8 and MSOP-8 footprint.
The TMP175 and TMP75 feature SMBus, Two-Wire, and I2C interface compatibility. The TMP175 device allows up to 27 devices on one bus. The TMP75 allows up to eight 8 on one bus. The TMP175 and TMP75 both feature an SMBus Alert function.
The TMP175 and TMP75 devices are ideal for extended temperature measurement in a variety of communication, computer, consumer, environmental, industrial, and instrumentation applications.
Features
- TMP175: 27 Addresses
- TMP75: 8 Addresses, NIST Traceable
- Digital Output: SMBus™, Two-Wire™, and I2C
Interface Compatibility - Resolution: 9 to 12 Bits, User-Selectable
- Accuracy:
- ±1°C (Typical) from –40°C to 125°C
- ±2°C (Maximum) from –40°C to 125°C
- Low Quiescent Current: 50-µA, 0.1-µA Standby
- Wide Supply Range: 2.7 V to 5.5 V
- Small 8-Pin MSOP and 8-Pin SOIC Packages
Connection
| Module Connection | Microbit Connection |
| VCC | 3v3 |
| GND | Gnd |
| SDA | SDA – 20 |
| SCL | SCL – 19 |
Code
#include <Wire.h>
byte TempHi; // Variable hold data high byte
byte TempLo; // Variable hold data low byte
boolean P_N; // Bit flag for Positive and Negative
unsigned int Decimal; // Variable hold decimal value
void Cal_Temp();
/*******************************************************************************
Setup
*******************************************************************************/
void setup()
{
Serial.begin(9600);
Wire.begin(); // join i2c bus (address optional for master)
delay(1000);
}
/*******************************************************************************
Main Loop
*******************************************************************************/
void loop()
{
const int I2C_address = 0x37; // I2C write address
delay(100);
Wire.beginTransmission(I2C_address);
Wire.write(1); // Setup configuration register
Wire.write(0x60); // 12-bit
Wire.endTransmission();
Wire.beginTransmission(I2C_address);
Wire.write((byte)0); // Setup Pointer Register to 0
Wire.endTransmission();
while (1)
{
delay(1000);
// Read temperature value
Wire.requestFrom(I2C_address, 2);
while(Wire.available()) // Checkf for data from slave
{
TempHi = Wire.read(); // Read temperature high byte
TempLo = Wire.read(); // Read temperature low byte
}
Cal_Temp ();
// Display temperature
Serial.print("The temperature is ");
if (P_N == 0)
Serial.print("-");
Serial.print(TempHi,DEC);
Serial.print(".");
Serial.print(Decimal,DEC);
Serial.println(" degree C");
}
}
void Cal_Temp()
{
if (TempHi&0x80) // If bit7 of the TempHi is HIGH then the temperature is negative
P_N = 0;
else // Else the temperature is positive
P_N = 1;
TempHi = TempHi & 0x7F; // Remove sign
TempLo = TempLo & 0xF0; // Filter out last nibble
TempLo = TempLo >>4; // Shift right 4 times
Decimal = TempLo;
Decimal = Decimal * 625; // Each bit = 0.0625 degree C
}
Output
Open the serial monitor and you will see something like this
The temperature is 23.5000 degree C
The temperature is 23.5625 degree C
The temperature is 25.3125 degree C
The temperature is 26.7500 degree C
The temperature is 27.8125 degree C
The temperature is 28.5000 degree C
The temperature is 28.9375 degree C
The temperature is 29.3750 degree C
The temperature is 29.6875 degree C
The temperature is 29.9375 degree C
The temperature is 30.1250 degree C
The temperature is 30.3125 degree C
Link
1pcs CJMCU-175 TMP175 27 Address Digital Temperature Sensor
