The sensor used for sensing temperature is the famous LM35DZ. This sensor is capable of measuring temperatures from 0ºC up to 55ºC and it’s very reliable.
The microcontroller used was once again the 16F88 from microchip.
Simple temperature meter - [Link]
Stian made this awesome sous-vide temp. controller, which he calls the “SousVide-O-Mator”. Built around an ATMega328 with the Arduino bootloader, it uses a DS18B20 temp. probe to monitor the temp, a 20×4 LCD to communicate with the user, and a solid-state relay to switch the rice cooker on and off. It also features one of the neatest, cleanest stripboard layouts I’ve ever seen (style counts!). He writes:
My brand spanking new homemade Sous Vide controller (PID controller for cooking). By connecting the relay to my rice cooker and putting the probe and a small aquarium pump inside I’m able to very accurately control the water temperature..
This is basically a heating immersion circulator as used by some fancy restaurants – readily made equipment cost in the range of $1000.. So I made one myself on the cheap (controller + rice cooker + water pump). This can be used to cook meat to perfection
Perfect for Sous Vide cooking! ( For more information about Sous Vide: http://en.wikipedia.org/wiki/Sous-vide )
SousVide-O-Mator - [Link]
RasterWeb! Logging the temperature and humidity… [via]
Last November one of the Arduino-based projects I started working on was a temperature logger for the office. With winter coming up I wanted to see just how cold it got. (The office is in a converted attic, and the heating and cooling leaves much to be desired.)
I picked up a TMP36 – Analog Temperature sensor and got it wired up and wrote some hacky perl code to read the data and log it. I never really got it out of the experimentation stage, and ended up pulling the Arduino out for another project. (Isn’t that often the case!?)
So last month when Adafruit came out with the DHT22 temperature-humidity sensor I figured I should grab one, and maybe I’d get around to finishing the project.
My temperature (and humidity!) logger is still not done, but I did whip up something to run this week while Wisconsin is having a heat wave. The office has a window air conditioning unit, but it only runs when someone is in the office. When no one is there, it gets hot. How hot? Well, now we know….
Logging the temperature and humidity - [Link]
Shawon Shahryiar (from Bangladesh) describes in this project about the HSM-20G sensor and its interfacing with the Atmega8 for measuring the ambient temperature and relative humidity. HSM-20G is an analog sensor that converts the ambient temperature and relative humidity into standard output voltages which can be measured through the ADC channels of Atmega8. With the use of the calibration curve provided in the datasheet, these analog voltages can be converted back to the temperature and relative humidity.
Atmega8 + HSM-20G to measure the relative humidity and temperature - [Link]
This tutorial is for our new BMP085 Barometric Pressure sensor. We show how to wire it up to your microcontroller, read the current pressure and temperature from the chip. We also show how to calculate altitude and weather-corrected altitude.
The BMP085 is a basic sensor that is designed specifically for measuring barometric pressure (it also does temperature measurement on the side to help). It’s one of the few sensors that does this measurement, and its fairly low cost so you’ll see it used a lot. You may be wondering why someone would want to measure atmospheric pressure, but its actually really useful for two things. One is to measure altitude. As we travel from below sea level to a high mountain, the air pressure decreases. That means that if we measure the pressure we can determine our altitude – handy when we don’t want the expense or size of a GPS unit. Secondly, atmospheric pressure can be used as a predictor of weather which is why weathercasters often talk about “pressure systems”
BMP085 Sensor Tutorial - [Link]
The TC74 chip is a serially accessible, digital temperature sensor from Microchip Technology that measures the surrounding temperature through its onboard solid-state sensor and provides it in an 8-bit digital word. This tutorial from Embedded Lab describes in detail about the TC74 sensor and its communication interface through an experiment that uses a PIC microcontroller to read the measured temperature from the sensor.
How to use Microchip’s TC74 sensor for temperature measurement - [Link]
A new MEMS device from Texas Instruments promises to make non-contact IR temperature sensing much easier and less expensive than existing methods. The TMP006 is a complete single-chip, passive IR temperature sensor with integrated MEMS thermopile, signal conditioning circuitry, 16-bit ADC, local temperature and voltage references, and both I2C and SMBus digital interfaces, all in a chip measuring 1.6 x 1.6 mm. [via]
MEMS device revolutionises non-contact temperature sensing – [Link]
ezflyer made a RS-485 network temperature sensor: [via]
This design will be used as part of my home automation system to measure temperatures in various parts of the house. I already have the wiring in place for an extensive RS-485 network, so the installation of the individual sensors will be easy. I’m currently working on a wireless version for my hot tub, and for an unattached workshop/garage.
This design is based on the PIC 16F648A processor, the MAX485 RS-485 interface IC, and the TC77 integrated temp. sensor. Each board has a (software) programmable network address, and network biasing (if required).
RS-485 network temperature sensor – [Link]
Joe writes: TI have announced a tiny (1.6mm sq), low power and low cost (~$2) IR temperature sensor [via]
Enables contactless temperature measurement in portable and consumer electronic applications
Developed through TI’s expertise in MEMS technology, the TMP006 is the first of a new class of ultra-small, low power, and low cost passive infrared temperature sensors. It has 90% lower power consumption and is more than 95% smaller than existing solutions, making contactless temperature measurement possible in completely new markets and applications.
Single-chip digital IR temperature sensor - [Link]
A thermistor is a thermal resistor – a resistor that changes its resistance with temperature. Technically, all resistors are thermistors – their resistance changes slightly with temperature – but the change is usually very very small and difficult to measure. Thermistors are made so that the resistance changes drastically with temperature so that it can be 100 ohms or more of change per degree! [via]
Sensor tutorials – Thermistor – [Link]