Tag Archives: temperature

Make an Arduino Temperature Sensor (Thermistor Tutorial)

In this video, Circuit Basics walks us through the steps in setting up a thermistor temperature sensor on an Arduino Uno. First they show how to output the temperature readings to your serial monitor. Then they go over how to connect and output the temperature readings to a 16×2 LCD display.

Make an Arduino Temperature Sensor (Thermistor Tutorial) [Link]

Designing a simple and cheap temperature logger

pickandplace.wordpress.com writes:

I started with making the TMP102 temperature sensor work. Nothing to say in particular, it’s just an other I2C-small-package-sensor. Or rather SMBus, but apart from the minimum speed clock requirements on the SMBus, the two protocols are alike.

Designing a simple and cheap temperature logger – [Link]

How to Set Up the DHT11 Humidity Sensor on an Arduino

circuitbasics.com has a new tutorial on how to interface DHT11 humidity sensor to Arduino board. Sample code is provided

Because of their low cost and small size, DHT11 humidity and temperature sensors are perfect for lots of different DIY electronics projects. Some projects where the DHT11 would be useful include remote weather stations, home environment control systems, and agricultural/garden monitoring systems.

How to Set Up the DHT11 Humidity Sensor on an Arduino – [Link]

Intel(r) Quark(tm) micrcontroller D2000 based Environmental sensors board

Sergey Kiselev designed and built an Intel Quark D2000 micrcontroller based Environmental sensors board:

This is a fairly small (51 x 51 mm) board, equipped with a low power Intel Quark D2000 microcontroller, and several sensors (accelerator, temperature, humidity, atmospheric pressure), as well as a mikroBUS compatible header and a Grove compatible connectors, that can be used to connect additional sensors, memory, or radio modules. The board can be used to monitor the environment conditions, and store or transmit the data to a remote system for further processing.

Intel(r) Quark(tm) micrcontroller D2000 based Environmental sensors board – [Link]

Temperature alarm for boiling milk

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Domen Ipavec shares his temperature alarm for boiling milk. Temperature alarm uses an Atmel attiny841 microcontroller, DS18B20 high temperature waterproof temperature sensor from adafruit, 2×16 HD44780 LCD and a buzzer to do its job.

Anyone who has ever boiled milk on the stove knows, that it has a nasty habit of overflowing. That is why I created the temperature alarm for boiling milk to be used my mother. It continuously measures the temperature of the milk and sounds an alarm when the temperature is over the preset alarm value.

Temperature alarm for boiling milk – [Link]

Temperature sensors accurate to -40°C

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by Denis Meyer @ elektormagazine.com:

With a local (on chip) precision of ±1°C over a range of temperature from –40°C to +65°C, and a remote (up to 3 external sensors) precision of ±1°C extended up to +125°C, the MCP990X digital temperature sensor offers an economic and flexible solution for external of industrial environments.

Temperature sensors accurate to -40°C – [Link]

CHIP Computer Project: CPU Temperature Monitor with OLED display SSD1306

Today educ8s.tv is going to connect an OLED display to the CHIP 9$ computer in order to monitor its CPU temperature in real time.

I received the CHIP single board computer about a year ago. It is an impressive board, it costs $9 and it offers a 1GHz CPU, 256MB of RAM wifi Bluetooth and many more things. You can watch my review of the CHIP computer by clicking on the card here. As you can see the CHIP computer is a lot smaller than the Raspberry Pi 3 board and of course it costs a lot less. One year later, the software developed for the CHIP computer is mature and we can easily build some projects with it

CHIP Computer Project: CPU Temperature Monitor with OLED display SSD1306 – [Link]

Sensor IC gives accurate RH and temperature from 2x2mm outline

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ams’ ENS210 sensor module features temperature measurement accuracy of ±0.2°C over the entire range 0°C to 70°C; the device also outputs relative humidity measurements on its I²C interface, enabling, ams says, portable and connected smart home devices to improve performance and implement new features. By Graham Prophet @ edn-europe.com:

The ENS210 is an high performance digital output sensor which monolithically integrates one relative humidity sensor and one high-accuracy temperature sensor. The device is encapsulated in a QFN4 package and includes an I²C slave interface for communication with a master processor.

Using Resistance Temperature Detector (RTD) With Arduino

Most of hardware developers have used a temperature sensor in one or more of theirs projects. There are many types of temperature sensors, such as LM35, thermistors, and resistance thermometers. These types differ in response speed, temperature ranges, accuracy, and other factors.

Resistance thermometer, which also known as Resistance Temperature Detector (RTD), is a device used to measure temperature by changing its resistance depending on the surrounding temperature. It has a slow response time but provides accurate values. A RTD consists of a length of fine wire wrapped around a ceramic or glass core. The RTD wire is a pure material, typically platinum, nickel, or copper.

This instructable shows a full guide of how to use a RTD with Arduino, it uses a two wire PT100 RTD, an Arduino, 3 LM741 operational amplifiers, and resistors.

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The first part of the circuit is about converting the resistance change of PT100 to a voltage change so the Arduino can read it. This operation can be done using a voltage divider, but for a specific range of 80 to 150 ohms (-51.85 to 129.87 degrees C) the divider has a DC offset which will decrease the sensitivity when amplifying this voltage.

To solve this issue you can use a Wheatstone Bridge, an electrical circuit used to measure an unknown electrical resistance by balancing two legs of a bridge circuit, to get rid of the DC offset and to increase output sensitivity. The values of Wheatstone resistors had chosen to limit current flow and to increase linearity of the output.

Wheatstone Bridge
Wheatstone Bridge

The output of the previous circuit is calculated by subtracting Vb+ and Vb- and then amplifying the result to be readable. To do this you need a differential amplifier, but there are two problems will occur when connecting this amplifier to the output of the bridge: the loading effect and changing the gain.

The loading effect means that the input resistors into the amplifier are affecting the voltage drop across the PT100 and changing the results. Changing the gain of the amp requires you to change at least two resistors, so having two potentiometers which have the same value will be annoying.

This problems had been solved by an instrumentation amplifier which acts as a buffer amplifier to separate the two halves of the circuit, the bridge and amplification, as well allows amplifying the input by changing just one potentiometer.

Instrumentation Amplifier Circuit
Instrumentation Amplifier Circuit

The last step is powering the circuit. As shown in the past circuit, there are Vcc+ and the Vcc-, because it needs both positive and negative voltage to function properly. These voltages can be generated using only one 12V power source, its circuit uses a buffer amplifier of gain 1 to create a virtual ground by passing half the supply voltage through the buffer amp which will act as the ground. Then the 12V will work as the +6V and the actual GND terminal will be -6V.

Powering Circuit
Powering Circuit

The full circuit was designed using  Autodesk Circuits.io, a platform that lets you create circuits on breadboard, edit circuit diagram and pcb diagram, and it also lets you simulate the circuit from the breadboard. You can even program an Arduino and connect it in the breadboard mode. If you want to duplicate the circuit and add your own values, just edit the design here.

This project is open source, you can find a detailed description of how the circuit works, circuits diagrams, equations, and source code at the project page at Instructables.com.

Clinical-grade human body temperature sensor has ±0.1°C accuracy

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Maxim Integrated has posted details of the MAX30205 temperature sensor for thermometer applications. The sensor accurately measures temperature and provide an overtemperature alarm/interrupt/shutdown output. by Graham Prophet @ edn.com

The chip converts the temperature measurements to digital form using a high-resolution, sigma-delta, ADC. Accuracy meets clinical thermometry specification of the ASTM E1112 when soldered on the final PCB. Communication is through an I ²C-compatible 2-wire serial interface that accepts standard write byte, read byte, send byte, and receive byte commands to read the temperature data and configure the behaviour of the open-drain overtemperature shutdown output.

Clinical-grade human body temperature sensor has ±0.1°C accuracy – [Link]