Microchip Technology

user Occupation hasn't been added


  • Bluetooth Connected Thermometer

  • Created: Oct 18, 2016

    • view181
    • comment0
    • bookmark0
    • fork0


No description available.


Thermometers have been used for a long time now especially in the medical industry. There were liquid-filled glass thermometers, which were using alcohol and mercury, that if broken can be extremely toxic to both humans and the environment. To avoid harmful effects of these kinds of thermometers, electronic thermometers can be used. Electronic thermometers, often-called digital thermometers, use electronic sensors to measure temperature and display it’s reading into numeric values.

This circuit is an electronic thermometer, based on a thermometer demonstration board from Microchip, implemented using an infrared thermal sensor to measure a person’s temperature. This thermometer is capable of connecting to Bluetooth devices such as smartphones, smartwatches and tablets, where it can display its temperature measurement. This design is constructed using the PIC16F1519 microcontroller (MCU), the RN42 Bluetooth module and the MLX90615 thermal sensor. Two capacitive touch pads (SW1 and SW2) are available to control the thermometer to start reading body temperature. These capacitive pads are connected to the PIC16F1519 MCU, which is integrated with capacitive touch sensing module. To measure body temperature, the thermometer is run across the forehead of the person. After that, the temperature is displayed through an onboard OLED display. The temperature data is also displayed in your Bluetooth devices through the RN42 module. Two AAAA batteries running through a boost regulator and a linear regulator to provide a 3.3V are used to power the circuit.

Some Bluetooth connected thermometers are already available in the market today. They are usually designed for babies avoiding them to be disturbed in their sleep when reading their body temperatures that might cause stress to them. This concept of measuring body temperature is also being integrated into many consumer products such as connected fitness and medical activity trackers.