rahulkar @ instructables.com writes:
This is a complete DIY project which requires a handful of components such as the ATtiny 85, LM35, MAX7219 and a couple of resistors and capacitors running off a regulated 5 V supply.
Temperature Measurement Range : 0 to 150′C / 32 to 300’F
Controller: ATtiny 85
Display type – 4 digit multiplexed 7 segment display (Common Cathode type)
Programming Language: Arduino
The setup can display both in Celsius and Fahrenheit. By default the temperature is shown in Celsius but can be toggled to display in Fahrenheit using the push button.
7 Segment Digital Thermometer using ATtiny 85 - [Link]
The MAX31629 I2C digital thermometer and real-time clock (RTC) integrates the critical functions of a real-time clock and a temperature monitor in a small-outline 8-pin TDFN package. Communication to the device is accomplished through an I2C interface. The wide power-supply range and minimal power requirement of the device allow for accurate time/temperature measurements in battery-powered applications. The digital thermometer provides 9-bit to 12-bit temperature readings that indicate the temperature of the device.
MAX31629 – I2C Digital Thermometer and Real-Time Clock - [Link]
Kerry Wong writes:
In this post, I will show you yet another thermometer/hygrometer build. But instead of using an LCD or 7 segment display for the output, I decided to go retro, using two “needles” to display the temperature and humidity readings instead. And to make the project more fun, I did not use analog meters for the output but chose to use two servos instead. The temperature humidity sensor I used is SHT21 from Sensirion, the same sensor I used in my temperature logging project before. In that project, the temperature and humidity readings were sent over the network and displayed on my web server (you can see the current readings in my lab here).
A digital thermometer hygrometer with analog displays - [Link]
This simple project is a digital thermometer using LM35 sensor and Attiny26 mcu to read the sensor value and display it on the LED display. LM35 output is amplified by 11 so can be read by mcu internal ADC. The hardware design files and firmware source code are available on the project’s page.
The sensor section is composed of LM35, OPA344 and some passive components. The LM35 is a precision temperature sensor that outputs 10mV per °C. Therefore, LM35 will output 0.25V or 250mV if it is measuring 25°C. The OPA344 is an operational amplifier that is configured as non-inverting amplifier with a gain of 11. The gain of OPA344 is set by R15 and R16. The OPA344 is used to multiply the voltage output of LM35 by 11. So, the output of OPA344 is 2.75V if the output of LM35 is 0.25V. R17 and C6 serves as a low pass filter for the output of OPA344. The values for R17 and C6 were arbitrarily chosen but for optimum performance, these values must be carefully chosen.
Simple Attiny26 based LM35 digital thermometer - [Link]
Ktulu_1 @ instructables.com writes:
The temperature in my office at work varies quite a bit depending on the time of day, season, and the whims of the other people I share the floor with. When I’m sitting at my desk shaking uncontrollably or sweating profusely it would be nice to know if it’s due to the temperature or just work related stress. A simple $5.00 thermometer would suffice, but where’s the fun in that? Making my own thermometer might cost ten times as much, but I might learn something in the process and it would be way cooler than any cheap store bought thing? I’d rather make something myself even if I have to pay a “maker’s premium.”
Tempduino – Arduino Based Temp and Humidity Display - [Link]
TrH Meter is a DIY microcontroller-based indoor thermometer plus hygrometer that displays temperature (F/C) and relative humidity on 4 seven segment LED displays which adjust their brightness level according to the surrounding illumination. The displays are 1 inch big, emits bright yellow color, and are readable from more than 50 ft away. It consists of a closed loop system that continuously assesses ambient light condition using an inexpensive light-dependent resistor (LDR) and uses that information to adjust the brightness of the display. The DHT11 sensor is used to measure temperature and relative humidity. The microcontroller used in this project is PIC16F688, and it runs at 4 MHz internal clock. A separate display driver chip (MAX7219) is used to control and refresh the display data on the seven segment LEDs. A 3-position slide switch controls power ON/OFF and Fahrenheit (F) or Celsius (C) scale select for temperature display. You can now preorder the project kit for a discounted price of $25 on Tindie. You will receive a preprogrammed PIC16F688 microcontroller in the kit.
TrH Meter project kit is now available for preorder on Tindie - [Link]
This temperature measuring project has a variety of range from -55 to +125 degree centigrade indicating on four common anode seven segment display module.The project measures an accurate temperature value point to point.
The main sensing part of the project is the semiconductor DS1820.It is based an one wire protocol device manufactured by Dallas semiconductor comes in different resolution such as DS18 S20(9-bit resolution), DS18B20 (12-bit resolution) etc.A microcontroller(AT89C2051) controls whole circuit function like receiving the serial data from DS1820 and converting the value for displaying the seven segment module.
DS1820 Digital Thermometer - [Link]
Reka Kovacs writes:
We are building an ArduSat (according to the Cubesat standards a satellite 10 cm long at the edges and 1 kg or less), on this satellite we would put up to 5 Arduino’s and plug in 50+ sensors into them as well as 2 optical and 1 IR camera. Once the satellite is on orbit we would then give access to the general public/citizen scientists to the payload ( Arduinos, sensors and camera) to upload their own scientific experiments. We plan to capture the attention of the DIY community, hackers and makers, amateur astronomers and in general those interested in space exploration and the next frontier.
Sensor wise we have so far magnetometers, tachometers, plasma sensor, photometer, thermometer, pressure sensor, space radiation (bitflip) sensor, Geiger counter and 2 optical and 1 IR camera etc.The idea is that people can rent scientific packages for a week, during the week they run their experiment we will send data constantly back to them to analyze. Imagine general public, including teachers having access to experiment platform in space for a couple of hundreds of dollar and they analyze data and engage students, friends etc., it could revolutionize the way people see space. Also we are looking for feedback from people interested in the project. We want to hear their ideas or sensors and experiments!
ArduSat – Your Arduino Experiment in Space - [Link]
A digital multimeter is a very useful instrument that combines several measurement functions in one unit. A typical multimeter includes features of a variable-range ohmmeter, voltmeter, and ammeter. Some of them also include capabilities of testing diodes and transistors. In this article, I am going to talk about a technique of adding thermometer feature to a regular digital multimeter. The technique is very simple and uses one temperature sensor along with two resistors and a DPDT slide switch.
Add a thermometer to your digital multimeter - [Link]
Build a circuit that displays four channels 0-100C using Pt100 as the temperature sensor. Wichit Sirichote writes:
The RTD or the Pt100 is one of the high accuracy temperature sensor for laboratory. Using the high resolution delta-sigma converter, enables designer to use a simple voltage divider circuit for measuring the resistance of the RTD without the need of any DC amplifications. This instrument shows how to use the LTC2420, 20-bit delta-sigma converter and the LM385 reference voltage for measuring four Pt100 sensors and displays on the text LCD.
4-Channel Pt100 Thermometer - [Link]