Thermo 3 click

Thermo 3 click carries TMP102, a digital temperature sensor IC with a tiny footprint of only 1.6mm x 1.6mm. The click is designed to run on a 3.3V power supply only. It communicates with the target MCU through mikroBUS™ I2C pins (SCL, SDA), and an additional Alert pint (INT on the default mikroBUS™ configuration).

TMP102 digital temperature sensor

Without requiring calibration, TMP102 is accurate within 0.5°C. Measurement range is between -25°C to 85°C. An integrated 12-bit ADC allows for measurement resolutions down to 0.0625°C.

Alert pin

You can set up an overtemperature alert using the ALERT pin (which sends an interrupt to the target board MCU). The sensor creates a highly linear output and therefore simple to use.

The ADD SEL jumper

Thermo 3 click™ has an ADD onboard jumper (zero ohm resistor) for specifying the I2C address.

Application

Because of its accuracy, Thermo 3 click is ideal for thermal-management and thermal protection applications, especially for extended measurements (in thermostats, office machines, industrial instrumentation applications).

Specification

Pinout diagram

This table shows how the pinout on Thermo 3 click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin	mikroBUStm				Pin	Notes
Not connected	NC	1	AN	PWM	16	NC	Not connected
Not connected	NC	2	RST	INT	15	ALERT	Overtemperature alert
Not connected	NC	3	CS	TX	14	NC	Not connected
Not connected	NC	4	SCK	RX	13	NC	Not connected
Not connected	NC	5	MISO	SCL	12	SCL	Serial Clock
Not connected	NC	6	MOSI	SDA	11	SDA	Serial Data
Power supply	+3.3V	7	3.3V	5V	10	NC	Not connected
Ground	GND	8	GND	GND	9	GND	Ground

Programming

Code examples for Thermo 3 click, written for MikroElektronika hardware and compilers are available on Libstock.

This function reads the temperature from the sensor.

01 float Get_Temperature() {
02 char tmp_data[2];
03 int TemperatureSum;
04 float Temperature;
05 
06 tmp_data[0] = 0x00; // Address of Temperature register
07 I2C1_Start(); // Issue I2C start signal
08 I2C1_Write(TMP102_I2C_ADDR,tmp_data,1,END_MODE_RESTART); // Send byte (tmp_data[0])
09 I2C1_Read(TMP102_I2C_ADDR,tmp_data,2,END_MODE_STOP); // Read temperature data and store it in tmp_data
10 
11 TemperatureSum = ((tmp_data[0] << 8) | tmp_data[1]) >> 4; // Justify temperature values
12 
13 if(TemperatureSum & (1 << 11)) // Test negative bit
14 TemperatureSum |= 0xF800; // Set bits 11 to 15 to logic 1 to get this reading into real two complement
15 
16 Temperature = (float)TemperatureSum * 0.0625; // Multiply temperature value with 0.0625 (value per bit)
17 
18 return Temperature; // Return temperature data
19 }

Key features

• TMP102 digital temperature sensor
  • Temperature range: -25°C to 85°C
  • Resolution: 12 Bits
  • Low Quiescent Current:
    • 10-μA Active (max)
    • 1-μA Shutdown (max)
• Interface: I2C
• 3.3V power supply