by marc2203 @ importhack.wordpress.com:
I’m not going to explain in detail what is ESP8266 because if you have found this post I’m sure you already know it. But just in case, it is an awesome cheap board (less than 4$) with built-in wifi communication (802.11 b/g/n), and SPI, UART. You can also use its processor to run your code.
How to use ESP8266 ESP-01 as a SENSOR web client - [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]
BITalino is designed for anyone interested in building self-tracking applications based on information from your body.
BITalino is a low-cost, purpose-built, all-in-one hardware and software toolkit designed for quick and easy creation of cool projects with body signals, development of quantified self wearable devices or apps, and/or learning how to build medical devices. Comparative professional-grade tools for this purpose can easily cost in excess of $10,000; our vision is to make them available for anyone, and harness the power and creative thinking of the open-source movement to boost innovation in biosignal-based applications in unprecedented ways.
BITalino (r)evolution - [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]
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]
The most legendary PIN-diode which is also used as a nuclear radiation detector is the BPW34. It is available from several semiconductor manufacturers in different variants and was originally designed for visible and invisible wavelength up to the IR wavelength region. Since such a diode is sensitive to light the use as a nuclear radiation detector requires proper shielded against light. The cost of a BW34 diode is generally below 1 Euro.
Do-it-yourself PIN-diode counter - [Link]
Freescale Semiconductor today introduced the FXTH87 tire pressure monitoring system (TPMS) family, which is the smallest integrated package TPMS solution available at an extremely light weight of 0.3 grams. The FXTH87 family is 50 percent smaller than competing products, helping designers reduce overall bill of materials costs. Freescale’s newest TPMS system-in-package solution provides low power consumption combined with the highest level of functional integration in one package, featuring a dual-axis accelerometer architecture, pressure and temperature sensor, integrated MCU, RF transmitter and low frequency receiver.
Freescale introduces world’s smallest integrated tire pressure monitoring system - [Link]
An app note on Gamma-photon radiation detector (PDF) by Maxim:
A PIN photodiode, four low-noise op amps and a comparator are used to detect individual photons of gamma radiation. The schematic, design considerations and component selection are discussed.
Gamma-photon radiation detector - [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]