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]
The Company AMS AG has introduced the non-contact AS5601 Hall-based rotary magnetic position encoding chip. It works by sensing changes in the magnetic field components perpendicular to the surface of the chip and converts field changes into voltages to produce incremental A/B outputs and absolute position information that can be read over an I²C bus. Analog signals from the built-in Hall sensors are amplified and filtered before conversion to binary values. A hardwired CORDIC block (Coordinate Rotation Digital Computer) calculates the angle and magnitude of the magnetic field vector. Magnetic field intensity is used by the automatic gain control (AGC) to adjust the amplification level which compensates for temperature and magnetic field variations.
New Rotary Encoder - [Link]
by ohneschuh @ instructables.com:
Capacitive sensors are an elegant way to control an Arduino using the Capacitive Sensing Library. But the sensitivity and error tolerance depend strongly on the hardware (sensor) design. I found a design guideline here and tested different setups which mostly work well if the Arduino was powered by battery. But the sensor signal changes dramatically if I connect the Arduino to a power supply.
Actually I found a design for five (and more) sensors which works well powered with battery and power supply.
Capacitive Sensor Design - [Link]
Proximity sensors working on an induction principle are able to detect ferrous and non-ferrous metals very reliably.
For those of you, who already work in this field, there´s everything clear for you probably and you know well, that induction sensors are literally one of the keystones for an industrial automation. For all of you, who´re not familiar with these important components yet, we bring this short description.
Induction sensors use the fact, that metal parts placed near an oscillator coil are able to change condition in a given oscillating circuit. Such a change (stopping of oscillations) can be reliably evaluated and to gain a confirmation about a presence of a metal subject in the sensor´s range. Induction sensors typically work on a frequency of hundreds of Hz up to a few kHz.The bigger the size of a coil (and also a sensor), usually the higher is the resulting sensitivity of a sensor (sensing range). But at the same time a bigger sensor usually works on a lower frequency, that´s why even a maximum sensing frequency is lower. From this reason it´s usually better to use a smaller type to detect fast moving objects.
Omron, as a top class producer of industrial sensors has in its portfolio a lot of series of induction proximity sensors, in numerous versions. A typical representative of well-known widely used sensors is the Omron E2A series. E2A has increased detection range and it´s encapsulated in a body from a nickel pated brass (M12-M30) or a stainless steel (M8). A lot of versions and diameters can be found here (M8/M12/M18/M30), versions with connectors or wire leads and also shielded and unshielded versions.
„Shielded” means, that a metal sensor body reaches up to the front (sensing) portion of a sensor. In case of non-shielded versions the metal package is shorter, i.e. the plastic part seems to stand out of the sensor body. The result is that a non-shielded version is more sensitive even to sides (x), what can be advantageous in some applications. On the other hand, shielded versions provide possibility of a very close assembly of sensors next to each other. Series E2A has a high resistance to dust and water (IP67/ IP69k), shocks, vibrations, heat as well as electromagnetic interference.
E2A series is primarily intended for ferrous metals, but with a smaller sensitivity it´s also usable for non-ferrous metals. However in the Omron offer can be found series specially intended for aluminium and other non-ferrous metals and even types which are non-sensitive to ferrous metals.
A typical output of an induction sensor is a transistor (open collector) – PNP or NPN with protection components (diode + transil). Output transistor can be used to connect to an intelligent control unit, or for direct switching of circuits, or switching of relays.
Overview of Omron offer and hints for usage can be found in the Omron induction sensors application guide. Detailed description of the E2A brings the Omron E2A datasheet. Answers to many questions can be found on the Omron proximity sensors FAQs webpage.
Induction sensors don’t need a touch, they’re satisfied by proximity - [Link]
by Jordan Dimitrov @ edn.com:
While most carbon dioxide sensors use IR technology, electrochemical sensors are a serious competitor because of their high sensitivity, wide measurement range, and low price. As a rule, electrochemical sensors connect to a microcontroller through a buffer amplifier with an extremely low bias current (<1pA). The micro is needed to linearize the logarithmic response of the sensor. A good example of this approach is the SEN-000007 module from Sandbox Electronics, which uses an MG-811 CO2 sensor from Hanwei Electronics. Reference 1 reveals the circuits and the code, but does not specify accuracy.
Antilog converter linearizes carbon dioxide sensor - [Link]
Ioannis Kedros writes:
It’s been a long time since I’ve post a new hobby project of mine! I decided that is time to upload a new one! Like my Sensor Stick module this project will be about sensors as well.
You can find multiple modules out there with various sensing ICs that almost all of them look exactly the same! They are ugly and without properly markings on their surface.
For example, some of those don’t have the input voltage range on the PCB or the pin out names or even the sensor address (in the case of a digital I2C sensors for example). In order to find that info, you have to download files, unzip them, look the schematics of the module then the datasheet of the sensor etc. A time consuming method especially for a quick and dirty prototype!
embeddedday.com – Sensor Modules - [Link]