...
- Accuracy:
- Sensitivity:
- Signal Collecting Period: 2S
- Responsive to a wide scope of target gases
- Cost efficient
- Durable
- Require relatively clean air as an initial condition.
- Long time exposure to highly polluted air can significantly weaken its sensitivity.
Features- Switch
- Motion sensor
- Thief-guarding system
- Industrial automation
- Input voltage: DC 4.5~20V
- Static current: 50uA
- Output signal: 0,3V (Output high when motion detected)
- Sentry angle: 110 degree
- Sentry distance: max 7 m
- Soil moisture sensor based on soil resistivity measurement
- Easy to use
- 2.0cmX6.0cm grove module
- simple way to detect motion
- emitter side that sends out a beam of human-invisible IR light, then a receiver across the way which is sensitive to that same light
- When something passes between the two, and its not transparent to IR, then the 'beam is broken' and the receiver will let you know
- Detecting heat coming off outdoor surfaces to assess level of comfort for pedestrians
- "Loitering" detector to not just identify movement, but identify when a person is in an area for a while
- Detect febrile individuals without contaminating the sensor
- The sensor comes on a breakout board so it simply needs and Arduino and connecting wires
- The sensor detects temperature by reading IR input levels and converting them to voltage inputs which are then processed by and embedded processor
- The output is a temperature level which can be read via an Ardunio processor
- Find more information at http://www.adafruit.com/product/1296
- Rain gauge: self-emptying bucket-type rain gauge which activates a momentary button closure for each 0.011" of rain that are collected.
- Anemometer (wind speed meter): encodes the wind speed by simply closing a switch which each rotation. A wind speed of 1.492 MPH produces a switch closure once per second.
- Wind vane: reports wind direction as a voltage which is produced by the combination of resistors inside the sensor.
- Tight specification, low-distortion vertical geophone
- Extended spurious over 240 Hz, allowing full bandwidth at 2-ms sampling
- Sensitivity of 28.8 V/m/s
- Pressure Sensor (100lb but can get different ranges)
- tracing footsteps
- reconfiguring furniture when someone sits down
- measuring the weight of something
- Sensing area: (0.375 in.) diameter
- Requires: Arduino UNO or other Arduino compatible board; breadboard; M/M jumper wires; 1 MegaOhm Resistor; Arduino IDE for programming
- Basic code is provided on Sparkfun to get started
1.71V to 3.6V operation
29 μA typical run current at 16 ms sampling interval
3 μA in scan stop mode current
12 electrodes/capacitance sensing inputs in which 8 are
multifunctional for LED driving and GPIO
Integrated independent autocalibration for each electrode input
Autoconfiguration of charge current and charge time for each
electrode input
Separate touch and release trip thresholds for each electrode,
providing hysteresis and electrode independence
I2C interface, with IRQ Interrupt output to advise electrode status
changes
- -40°C to +85°C operating temperature range
- General Purpose Capacitance Detection
Switch Replacements
Touch Pads, Touch Wheel, Touch Slide Bar, Touch Screen Panel
Capacitance Near Proximity Detection
PC Peripherals
MP3 Players
Remote Controls
Mobile Phones
Lighting Controls
Chemical Sensors
- Alcohol sensor
- Input Voltage: 5V
- Working Current: 120mA
- Detectable Concentration: 20-1000ppm
- Grove Compatible connector
- Highly sensitive to alcohol.
- Fast response and resumes quickly after alcohol exposure.
- Long life.
- Compact form factor.
Misc.
- Magnetic Card (facts from Sparkfun and wikipedia)
- 30mil standard card with a low coercivity magnetic stripe.
- The stripe can contain up to 3 tracks of information.
- This card can be erased and written multiple times with a compatible writer.
- only .95 cents
- LoCo cards are much easier to erase and have a shorter lifespan
- Track 1 is written with code known as DEC SIXBIT
- his format was developed by the banking industry (ABA). This track is written with a 5-bit scheme (4 data bits + 1 parity), which allows for sixteen possible characters
- Walking, running, dancing or skipping
- Working machines
- Construction work – driving piles, demolition, drilling and excavating
- Moving loads on bridges
- Vehicle collisions
- Impact loads – falling debris
- Concussion loads – internal and external explosions
- Collapse of structural elements
- Wind loads and wind gusts
- Air blast pressure
- Loss of support because of ground failure
- Earthquakes and aftershocks
- Capacitive
- Capacitive displacement sensor
- Doppler effect (sensor based on effect)
- Eddy-current
- Inductive
- Laser rangefinder
- Magnetic, including Magnetic proximity fuse
- Passive optical (such as charge-coupled devices)
- Passive thermal infrared
- Photocell (reflective)
- Radar
- Reflection of ionising radiation
- Sonar (typically active or passive)
- Ultrasonic sensor (sonar which runs in air)
- Fiber optics sensor
- Hall effect sensor
- Light level measurements
- Acceleration sensing
- Cold chain monitoring
- Security Applications
- analog output, which duplicates the wave shape of the sensed current
- bipolar output, which duplicates the wave shape of the sensed current
- unipolar output, which is proportional to the average or RMS value of the sensed current
- unipolar, with a unipolar output, which duplicates the wave shape of the sensed current
- digital output, which switches when the sensed current exceeds a certain threshold
- How much or if the sensor is being flexed or bent
This sensor is designed for comprehensive monitor over indoor air condition. It's responsive to a wide scope of harmful gases, as carbon monixide, alcohol, acetone, thinner, formaldehyde and so on. Due to the measuring mechanism, this sensor can not output specific data to describe target gases' concentrations quantitatively. But it's still competent enough to be used in applications that require only qualitative results, like auto refresher sprayers and auto air cycling systems. This sensor does better in providing qualitative results over a wide scope of target gases. In this demo, we define 4 statuses for reference in the .cpp file. They are:
4. PIR Motion Sensor Module ($7.90 USD)
This Moisture Sensor can be used to detect the moisture of soil or judge if there is water around the sensor, let the plants in your garden reach out for human help. They can be very easy to use, just insert it into the soil and then read it. With the help of this sensor, it will be realizable to make the plant remind you : hey, i am thirsty now, please give me some water.
6. IR Breakbeam Sensors (Adafruit)
Wiring requirements
- 3.3V or 5V power
- Arduino
7. Contact-less Infrared Thermophile Sensor (Adafruit) ($9.95)
This sensor allows you to detect the temperature of an object from a distance. This occurs by detecting IR waves and using an already programmed algorithm to convert it into readable temperature.
Possible uses:
Details:
8. Weather Meter ($70)
Measures wind speed, wind direction and rainfall. Uses sealed magnetic reed switches and magnets and needs a voltage source to take measurements.
9. Liquid Level Sensor ($40)
Measures the level of a liquid. Resistive output that varies with the level of the fluid. No clunky mechanical floats, and easily interfaces with electronic control systems. The sensor’s envelope is compressed by the hydrostatic pressure of the fluid in which it is immersed. This results in a change in resistance that corresponds to the distance from the top of the sensor to the surface of the fluid. The sensor’s resistive output is inversely proportional to the height of the liquid: the lower the liquid level, the higher the output resistance; the higher the liquid level, the lower the output resistance.
Specifications
Sensor Length: 10.1" (257 mm) Thickness: 0.015" (0.381mm)
Width: 1.0" (25.4 mm)
Active Sensor Length: 8.4" (213 mm)
Resolution: < 0.01“(0.25 mm)
Actuation Depth: Nominal 1” (25.4 mm)
Reference Resistor (Rref): 1500
Connector: Crimpflex Pins
Temperature Range: 15°F - 150°F (-9°C - 65°C) Power Rating: 0.5 Watts (VMax = 10V)
10. Geophone ($60)
A geophone works by translating ground movement into voltage, which can easily be read by a microcontroller. The SM-24 geophone element is designed to offer the highest performance in seismic exploration based upon field-proven I/O Sensor technology. Low distortion, combined with excellent specifications, provide high-fidelity data. Basically, it’s a super low frequency microphone for the ground.
Features:
Microphone
A microphone, is an acoustic-to-electric transducer or sensor that converts sound in air into an electrical signal.
Features:
It produce an electrical signal from air pressure variations. sound is first converted to mechanical motion by means of a diaphragm, the motion of which is then converted to an electrical signal.
A complete microphone also includes a housing, some means of bringing the signal from the element to other equipment, and often an electronic circuit to adapt the output of the capsule to the equipment being driven. A wireless microphone contains a radio transmitter.produce an electrical signal from air pressure variations.
http://en.wikipedia.org/wiki/Microphone#Components
Hydrophone
A hydrophone is a microphone designed to be used underwater for recording or listening to underwater sound.
Features:
Most hydrophones are based on a piezoelectric transducer that generates electricity when subjected to a pressure change. Such piezoelectric materials, or transducers can convert a sound signal into an electrical signal since sound is a pressure wave.
A small single cylindrical ceramic transducer can achieve near perfect omnidirectional reception. Directional hydrophones increase sensitivity from one direction using two basic techniques: Focused transducers and Arrays.
http://en.wikipedia.org/wiki/Hydrophone
Rotary encoder
A rotary encoder, also called a shaft encoder, is an electro-mechanical device that converts the angular position or motion of a shaft or axle to an analog or digital code.
Two main types:
absolute and incremental (relative). The output of absolute encoders indicates the current position of the shaft, making them angle transducers. The output of incremental encoders provides information about the motion of the shaft, which is typically further processed elsewhere into information such as speed, distance, and position.
For absolute rotary encoder, there are following types in construction:
§Mechanical absolute encoders
A metal disc containing a set of concentric rings of openings is fixed to an insulating disc, which is rigidly fixed to the shaft. A row of sliding contacts is fixed to a stationary object so that each contact wipes against the metal disc at a different distance from the shaft. As the disc rotates with the shaft, some of the contacts touch metal, while others fall in the gaps where the metal has been cut out. The metal sheet is connected to a source of electric current, and each contact is connected to a separate electrical sensor. The metal pattern is designed so that each possible position of the axle creates a unique binary code in which some of the contacts are connected to the current source (i.e. switched on) and others are not (i.e. switched off).
Because brush-type contacts are susceptible to wear, encoders using contacts are not common; they can be found in low-speed applications such as manual volume or tuning controls in a radio receiver.
§Optical absolute encoders[edit]
The optical encoder's disc is made of glass or plastic with transparent and opaque areas. A light source and photo detector array reads the optical pattern that results from the disc's position at any one time.[5]
This code can be read by a controlling device, such as a microprocessor or microcontroller to determine the angle of the shaft.
The absolute analog type produces a unique dual analog code that can be translated into an absolute angle of the shaft.
§Magnetic absolute encoders[edit]
The magnetic encoder uses a series of magnetic poles (2 or more) to represent the encoder position to a magnetic sensor (typically magneto-resistive or Hall Effect). The magnetic sensor reads the magnetic pole positions.
This code can be read by a controlling device, such as a microprocessor or microcontroller to determine the angle of the shaft, similar to an optical encoder.
The absolute analog type produces a unique dual analog code that can be translated into an absolute angle of the shaft (by using a special algorithm).
§Capacitive absolute encoders[edit]
An asymmetrical shaped disc is rotated within the encoder. This disc will change the Capacitance between two electrodes which can be measured and calculated back to an angular value [6]
Proximity (inductive) Sensor
An proximity(inductive) sensor is an electronic proximity sensor, which detects metallic objects without touching them.
The sensor consists of an induction loop. Electric current generates a magnetic field, which collapses generating a current that falls asymptotically toward zero from its initial trans when the input electricity ceases. The inductance of the loop changes according to the material inside it and since metals are much more effective inductors than other materials the presence of metal increases the current flowing through the loop. This change can be detected by sensing circuitry, which can signal to some other device whenever metal is detected.
Elements of a simple inductive sensor.
1. Field sensor
2. Oscillator
3. Demodulator
4. Flip-flop
5. Output
Ultrasonic transducer
Ultrasonic transducers are transducers that convert ultrasound waves to electrical signals or vice versa.
Working principle:
These devices work on a principle similar to that of transducers used in radar and sonar systems, which evaluate attributes of a target by interpreting the echoes from radio or sound waves, respectively. Active ultrasonic sensors generate high frequency sound waves and evaluate the echo which is received back by the sensor, measuring the time interval between sending the signal and receiving the echo to determine the distance to an object. Passive ultrasonic sensors are basically microphones that detect ultrasonic noise that is present under certain conditions, convert it to an electrical signal, and report it to a computer.
Components:
Transducers
An ultrasonic transducer is a device that converts energy into ultrasound, or sound waves above the normal range of human hearing.
Compass
A compass is an instrument used for navigation and orientation that shows direction relative to the geographic cardinal directions, or "points".
Sun compass
A sun compass uses the position of the Sun in the sky to determine the directions of the cardinal points, making allowance for the local latitude and longitude, time of day, equation of time, and so on.
Pressure Sensors
Possible uses:
Key Facts:
Water flow sensor consists of a plastic valve body, a water rotor, and a hall-effect sensor. When water flows through the rotor, rotor rolls. Its speed changes with different rate of flow. The hall-effect sensor outputs the corresponding pulse Signal.
You will need Seeeduino / Arduino ,Water Flow Sensor,10K resistor,a breadboard and some jumper wires.
Wiring up the Water Flow Sensor is pretty simple. There are 3 wires: Black, Red, and Yellow. Black to the Seeeduino's ground pin Red to Seeeduino's 5v pin The yellow wire will need to be connected to a 10k pull up resistor.and then to pin 2 on the Seeeduino.
3. Proximity Capacitive Touch Sensor Controller
These keypads function by measuring the capacitance of twelve electrode points. When an object comes close to the electrode connector, the measured capacitance changes. This signals the MPR121 that something has touched a ‘button’. The board also has four mounting holes allowing it to be used as an input system in place of traditional buttons.
Features
Implementations
Typical Applications
Grove - Alcohol Sensor is a complete alcohol sensor module for Arduino or Seeeduino. It is built with MQ303Asemiconductor alcohol sensor. It has good sensitivity and fast response to alcohol. It is suitable for making Breathalyzer. This Grove implements all the necessary circuitry for MQ303A like power conditioning and heater power supply. This sensor outputs a voltage inversely proportional to the alcohol concentration in air.
OTHER
Designed to hold the hundreds to thousands of short data strings that are so commonly used when logging sensor data. Read/Write/Erase operations are done using simple one character commands in asynchronous serial format. A full 128 byte character string is written to memory in just 3 milliseconds.
Features
• 32Mb flash memory
• No drivers required
• Specifically designed to hold strings of up to 128 characters long • Read/ Write/Erase 32,760 individual strings
• Fast operation read/write a 128 byte string in just 3ms
• Write to memory confirmation
• Two different organized read back methods
• 20 year data retention
• Up to 3,276,000,000 program/erase cycles
• Simple asynchronous serial connectivity (voltage swing 0-VCC)
• Simple instruction set consisting of only 7 commands
• Debugging LED’s
• 3.3 volt operation
• Low power consumption
• Well suited for airborne applications weighing only 1.53 grams
Existing Sensor Wiki:
http://www.sensorwiki.org/doku.php/sensors/introduction
Accelerometer
Accelerometers can measure static, or dynamic acceleration forces. Static forces are measures like gravity which is constantly pulling, while dynamic forces are measured by movement or vibration of the sensor. It can also measure tilt based on the relative force to the ground. These are useful for monitoring or sensing the movement of an object. There are multiple ways to make accelerometers. The two most common are using crystals that when accelerated move closer and create an electric charge, or sensing in capacitance and converting that to a charge.
Measures
Proximity Sensors
A proximity sensor is a sensor able to detect the presence of nearby objects without any physical contact. A proximity sensor often emits an electromagnetic field or a beam of electromagnetic radiation (infrared, for instance), and looks for changes in the field or return signal. The object being sensed is often referred to as the proximity sensor's target. Different proximity sensor targets demand different sensors. For example, a capacitive or photoelectric sensor might be suitable for a plastic target; an inductive proximity sensor always requires a metal target. The maximum distance that this sensor can detect is defined "nominal range". Some sensors have adjustments of the nominal range or means to report a graduated detection distance. Proximity sensors can have a high reliability and long functional life because of the absence of mechanical parts and lack of physical contact between sensor and the sensed object. Proximity sensors are commonly used on smartphones to detect (and skip) accidental touchscreen taps when held to the ear during a call.[1] They are also used in machine vibration monitoring to measure the variation in distance between a shaft and its support bearing. This is common in large steam turbines, compressors, and motors that use sleeve-type bearings.
Types:
Applications:
Parking sensors, systems mounted on car bumpers that sense distance to nearby cars for parking
Ground proximity warning system for aviation safety
Vibration measurements of rotating shafts in machinery [2]
Top dead centre (TDC)/camshaft sensor in reciprocating engines.
Sheet break sensing in paper machine.
Anti-aircraft warfare
Roller coasters
Conveyor systems
Beverage and food can making lines[3]\
Improvised Explosive Devices or IEDs
Mobile devices
Light Sensor
Two Modes: Light Mode and Dark Mode. Light mode sends a higher signal based on more light,
And dark mode sends a higher signal based on the darker it is.
Wireless ID Sensor
An RFID device that supports sensing and computing: a microcontroller powered by radio-frequency energy.[1] That is, like a passive RFID tag, WISP is powered and read by a standard off-the-shelf RFID reader, harvesting the power it uses from the reader's emitted radio signals. To an RFID reader, a WISP is just a normal EPC gen1 or gen2 tag; but inside the WISP, the harvested energy is operating a 16-bit general purpose microcontroller. The microcontroller can perform a variety of computing tasks, including sampling sensors, and reporting that sensor data back to the RFID reader. WISPs have been built with light sensors, temperature sensors, and strain gauges. Some contain accelerometers.
Applications:
Occupancy/Motion Light Sensors
Turn lights on and off based on Motion Detection.
Inertial Measurement Units
Measures Velocity, Orientation, and Gravitational forces using a combination of accelerometers, gyroscopes, and sometimes magnetometers. Mostly used for navigation systems.
Current Sensor
Current sensors measure electric current in a wire and creates a proportional signal from it. The signal can be either analog or digital. The resulting signal can be used for a variety of purposes ranging from being utilized in a control system, analyzed in a data set, or display active current flows.
Alternating Currents:
Direct Currents:
Gyroscope
Measures and maintains orientation through preserving angular momentum.
Uses
Flex Sensor
Flex sensors are passive resistive devices that can be used to detect bending or flexing. The flex sensor shown in this article is a bi-directional flex sensor that decreases its resistance in proportion to the amount it is bent in either direction.
Measures
Vibration/Motion sensor - $2.95
• What does it do/measure – a film moves back and forth when impacted, or movement occurs that disrupts its flow. This type of sensor can be used for Vibration Sensing in devices like Washing Machines, or sensitive components that can shut down before being damaged by movement, Car Alarms, Body Movement and Security Systems
• What components are needed - piezoelectric PVDF polymer film with screen-printed Ag-ink electrodes, laminated to a 0.125 mm polyester substrate, and fitted with two crimped contacts. Using resistors, capacitors, transistors, regulators, relays and a transformer one can connect the film to create the sensor.
• What are the inputs, both generally and technically? Piezoelectricity, Greek for "pressure" electricity, allows vibration to be detected. An early use was the development of underwater sonar. Inputs are voltage to create surface detection and force to trigger the sensor at predetermined frequencies.
• How does it measure the input? How does it convert what’s being measured to bits? Bending of the polymer film creates very high strain within the piezopolymer and therefore high voltages are generated. When the assembly is deflected by direct contact, the device acts as a flexible "switch", and the generated output is sufficient to trigger MOSFET or CMOS stages
• What is the output, both generally and technically? Information about movement, sensitivity can be changed for different circumstances, cut off capabilities at various frequencies.
• Where can one find more information? http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/ForceFlex/LDT_Series.pdf
https://www.sparkfun.com/datasheets/Sensors/Flex/MSI-techman.pdf
http://www.jameco.com/Jameco/PressRoom/proximity.html
Indoor Positioning System
A solution to locate objects or people inside a building using radio waves, magnetic fields, acoustic signals, or other sensory information collected by mobile devices.
Instead of using satellites, IPS solutions rely on different technologies, including distance measurement to nearby anchor nodes (nodes with known positions, e.g., WiFi access points), magnetic positioning, dead reckoning. They either actively locate mobile devices and tags or provide ambient location or environmental context for devices to get sensed.
Wifi: The localization technique used for positioning with wireless access points is based on measuring the intensity of the received signal (received signal strength in English RSS) and the method of "fingerprinting".
(Before mobile devices) So called asset tags were designed to track and monitor things, like shipping containers, medical assets, or even tag-toting people. The tags periodically collect AP signal data and report to a network-side server that does the calculating and tracking using RSSI (received signal strength indicator)-based localization and/or a previous RF fingerprint (a walkabout calibration). The server displays tag location on a map to help the end-user find something/someone. Or, geo-fencing concepts are used to trigger alerts when specific conditions are met (e.g. a tagged asset exits the building). Despite being relatively easy to overlay on existing Wi-Fi infrastructures, asset-tracking solutions require network-side servers, and have not seen any major overhaul in the past few years.
For the consumer world, mobile devices are displacing tags as the “thing” to locate.
Bluetooth (iBeacon): Bluetooth is all about proximity, not about exact location. Bluetooth was not intended to offer a pinned location like GPS, however is known as a geo-fence or micro-fence solution which makes it an indoor proximity solution, not an indoor positioning solution. Micromapping and indoor mapping[25] has been linked to Bluetooth[26] and to the Bluetooth LE based iBeacon promoted by Apple Inc.. Large-scale indoor positioning system based on iBeacons has been implemented and applied in practice.
Grid concepts: Instead of long range measurement, a dense network of low-range receivers may be arranged, e.g. in a grid pattern for economy, throughout the space being observed. Due to the low range, a tagged entity will be identified by only a few close, networked receivers. An identified tag must be within range of the identifying reader, allowing a rough approximation of the tag location. Advanced systems combine visual coverage with a camera grid with the wireless coverage for the rough location.
'Triangulation' methods of Angle of arrival, Timing of arrival: Angle of arrival (AoA) is the angle from which a signal arrives at a receiver. AoA is usually determined by measuring the time difference of arrival (TDOA) between multiple antennas in a sensor array. In other receivers, it is determined by an array of highly directional sensors—the angle can be determined by which sensor received the signal. AoA is usually used with triangulation and a known base line to find the location relative to two anchor transmitters.
Time of arrival (ToA, also time of flight) is the amount of time a signal takes to propagate from transmitter to receiver. Because the signal propagation rate is constant and known (ignoring differences in mediums) the travel time of a signal can be used to directly calculate distance. Multiple measurements can be combined with trilateration and multilateration to find a location. This is the technique used by GPS. Systems which use ToA, generally require a complicated synchronization mechanism to maintain a reliable source of time for sensors (though this can be avoided in carefully designed systems by using repeaters to establish coupling). The accuracy of the TOA based methods often suffers from massive multipath conditions in indoor localization, which is caused by the reflection and diffraction of the RF signal from objects (e.g., interior wall, doors or furniture) in the environment. However, it is possible to reduce the effect of multipath by applying temporal or spatial sparsity based techniques.