by Michael Mayes @ edn.com:
Although temperature is a fundamental aspect of our lives, it is difficult to measure accurately. Before the era of modern electronics, Galileo invented a rudimentary thermometer capable of detecting temperature changes. Two hundred years later, Seebeck discovered the thermocouple, a device capable of generating a voltage as a function of temperature gradients in dissimilar metals. Today, thermocouples as well as temperature dependent resistance elements (RTDs and thermistors) and semiconductor elements (diodes) are commonly used to electrically measure temperature. While methods for extracting temperature from these elements are well known, accurately measuring temperatures to better than 0.5ºC or 0.1ºC accuracy is challenging (see Figure 1).
Temperature-to-Bits converter helps solve challenges in sensor measurement - [Link]
by Nick Lavars:
While the stench of rotting food would cause you to stop from chowing down, chances are it became unfit for consumption some time before those funky aromas wafted through your nostrils. Chemists at MIT have been working on a wireless, inexpensive sensor that, among other things, identifies spoiled food early by detecting gases in the air. It then shares its data with a smartphone, potentially alerting users to that soon-to-be moldy fruit in the bottom of the fridge.
Wireless sensor alerts your smartphone as food begins to spoil - [Link]
praveen @ circuitstoday.com:
This article is about interfacing gyroscope to arduino. Gyroscope is a device used for measuring the angular velocity in the three axes. It works under the concepts of angular momentum and can be used to determine the orientation of an object. Typical applications of gyroscope includes missile guidance, flight control, smart phones, game station joy sticks etc. Mechanical gyroscopes, MEMS gyroscope, optic fiber gyroscope, ring laser gyroscope.
Interfacing gyroscope to arduino - [Link]
by noelportugal @ instructables.com:
The day I read that a new $5 wifi module was available, I order a few of them to test. Now, a few weeks later I want to share my experience.
This is a very simple demo using the ESP8266 and Arduino to update a remote server (https://thingspeak.com/) using a digital temperature sensor.
ESP8266 Wifi Temperature Logger - [Link]
The LTC2983 measures a wide variety of temperature sensors and digitally outputs the result, in °C or °F, with 0.1°C accuracy and 0.001°C resolution. The LTC2983 can measure the temperature of virtually all standard (type B, E, J, K, N, S, R, T) or custom thermocouples, automatically compensate for cold junction temperatures and linearize the results. The device can also measure temperature with standard 2-, 3-, or 4-wire RTDs, thermistors, and diodes. It has 20 reconfigurable analog inputs enabling many sensor connections and configuration options. The LTC2983 includes excitation current sources and fault detection circuitry appropriate for each type of temperature sensor. The LTC2983 allows direct interfacing to ground referenced sensors without the need for level shifters, negative supply voltages, or external amplifiers. All signals are buffered and simultaneously digitized with three high accuracy, 24-bit ΔΣ ADC’s, driven by an internal 10ppm/°C (maximum) reference.
LTC2983 – Multi-Sensor High Accuracy Digital Temperature Measurement System - [Link]
Linear Technology Corporation has announced the LTC2983 high performance digital temperature measurement IC. The IC is a single chip solution to temperature sensor interfacing; it has 20 input channels for sensor connection and each input can be assigned the characteristics appropriate to the sensor used. This includes 8 standard thermocouple types, 8 RTDs, 8 thermister profiles and an external diode; if you are using a custom sensor you can also specify a custom table.
In addition to the impressive sensor capability the IC measures temperature with an accuracy of 0.1°C and a resolution of 0.001°C. The LTC2983 allows direct interfacing to ground referenced sensors without the need for level shifters, negative supply voltages, or external amplifiers. All signals are buffered and simultaneously digitized with three high-accuracy, 24-bit ΔΣ ADC’s, driven by an internal 10 ppm/°C (maximum) reference.
High Accuracy Universal Temperature Sensor IC - [Link]
by willseph @ imgur.com:
The web interface allows me to change the settings on my thermostat remotely, such as the set temperature range compressor and fan modes, as well as view any warning messages that may be reported.
It’s not exactly beautiful, but I’m a function-over-fashion person. The Raspberry Pi is in the middle, white power cable running down and a GPIO rainbow ribbon cord heading up to the relay module under the real thermostat.
Homemade Raspberry Pi smart thermostat - [Link]
I recently got my hands on a pair of Flir Lepton thermal imaging sensors and have spent the last week bringing them online in my spare time. These are absolutely incredible devices that I believe will pave the way to consumer devices incorporating thermal imaging cameras. The footprint of the camera module (and optical assembly) is about the size of a dime. The resolution is 80×60 at 14bpp which is remarkable despite sounding low.
Flir Lepton Thermal Imaging Sensor + Gameduino 2 - [Link]
by praveen @ circuitstoday.com:
A simple LPG sensor using arduino is shown in this article. This circuit indicates the amount of LPG in the air. The circuit sounds an alarm and trips a relay when the concentration is above a predetermined level. MQ2 is the gas sensor used in this project. MQ2 is an SnO2 based gas sensor which can sense gases like methane, propane, butane, alcohol, smoke, hydrogen etc. Since LPG primarily contains propane and butane, MQ2 sensor can be used for sensing LPG. The figure below shows the schematic and arrangement of an MQ2 gas sensor.
LPG sensor using arduino - [Link]
TI’s new HDC1000 integrated humidity and temperature sensor provides high accuracy and low power in a small, dust-resistant package.
Designers of building control equipment can implement accurate, energy-saving climate control in small spaces, while designers of home appliances and consumer goods can easily add humidity-sensing capabilities to their products.
High accuracy, low power
The HDC1000 consumes only 1.2 µA average current when measuring relative humidity and temperature at 11-bit resolution, once per second, extending battery life in remote applications.
HDC1000 – Low Power, High Accuracy Humidity Sensor with Integrated Digital Temperature Sensor - [Link]