Chemical Sensors

LPG Gas Sensor - MQ-6 Description:

This is a simple-to-use liquefied petroleum gas (LPG) sensor, suitable for sensing LPG (composed of mostly propane and butane) concentrations in the air. The MQ-6 can detect gas concentrations anywhere from 200 to 10000ppm.

This sensor has a high sensitivity and fast response time. The sensor's output is an analog resistance. The drive circuit is very simple; all you need to do is power the heater coil with 5V, add a load resistance, and connect the output to an ADC.

Carbon Monoxide Sensor - MQ-7

Description: This is a simple-to-use Carbon Monoxide (CO)sensor, suitable for sensing CO concentrations in the air. The MQ-7 can detect CO concentrations anywhere from 20 to 2000ppm.

This sensor has a high sensitivity and fast response time. The sensor's output is an analog resistance. The drive circuit is very simple; all you need to do is power the heater coil with 5V, add a load resistance, and connect the output to an ADC.

This sensor comes in a package similar to our MQ-3 alcohol sensor, and can be used with the breakout board below.

Pressure (touch) Sensor

Force Sensitive Resistor - Square
sku: SEN-09376

Description: This is a force sensitive resistor with a square, 1.75x1.5", sensing area. This FSR will vary its resistance depending on how much pressure is being applied to the sensing area. The harder the force, the lower the resistance. When no pressure is being applied to the FSR its resistance will be larger than 1MΩ. This FSR can sense applied force anywhere in the range of 100g-10kg.

Two pins extend from the bottom of the sensor with 0.1" pitch making it bread board friendly. There is a peel-and-stick rubber backing on the other side of the sensing area to mount the FSR.

These sensors are simple to set up and great for sensing pressure, but they aren't incredibly accurate. Use them to sense if it's being squeezed, but you may not want to use it as a scale.

Dimensions:
Overall length: 3.5"
Overall width: 1.75"
Sensing area: 1.75x1.5"

Link: http://www.sparkfun.com/commerce/product_info.php?products_id=9376

Biometrics

Fingerprint Scanner

Description: The Nitgen RS232 serial fingerprint scanner is a powerful ADSP-BF531 Blackfin based system. This scanner is capable of gathering and storing unique finger prints. Simply hold your finger on the optical scanner, query the device over serial, and you will be issued a unique ID. Use that ID within your embedded system to determine access levels, time clocks, door locks, etc.

Unit includes master controller board, optical reader, and ribbon cable to connect read to controller. We are trying to get pigtail interface cables made but in the interim, you will need to create your own connection to the serial connector.

Features:
Serial at 9600bps
3.3V@200mA
Capture in 0.2s
Verification in 1.0s

Webcam Sensors

Any webcam can be programmed to receive data ranging from simple images, and motion detection, to receiving infrared signals. The data can be reinterpreted by a computer to produce an effect aside from the typical viewing of an image on a digital screen. The following examples look at using a webcam to control external responses that are an extension of the obvious capabilities of the camera.

Using Processing software with JMyron WebCamExtra open source programming, new functions and unique outputs can be produced via a webcam including motion detection, color tracking, glob distinction, and pixel addressing.

http://webcamxtra.sourceforge.net/ - JMyron home page including open source downloads and tutorials.

Myron is the cross-platform, cross-language, open source, video capture and computer vision plugin. One core C++ object gets cross-compiled as a handful of high level language "wrapper" libraries. The wrapper for Java and Processing is called JMyron. The wrapper for Macromedia Director is called WebCamXtra. The aim of the project is to keep computer vision free and easy for the new media education and arts community.

Arduino Intro including Digital and Analog Sensors

For an intro to Arduino & Processing, see the course server. I have removed these files to keep them internal to our course.

Sensors & Actuators incl Processing Code

Sensors and Actuators

Distance and Motion Sensors

The following sensors respond to the movement and proximity of an object/user. The sensor responds by sending data through a processor and into software that can analyze and determine a set response.

Infrared Proximity Sensor

Description: Analog infrared distance sensor has an analog output that varies from 3.1V at 10cm to 0.4V at 80cm. The sensor has a Japanese Solderless Terminal (JST) Connector. Combined with settings determined in the Arduino or Processing software receiving the input signal, a response can be determined.

Infrared Transmitter & Receiver

Piezo Vibration Sensor - Large with Mass

Description: This basic piezo sensor is often used for flex, touch, vibration and shock measurements. A small AC and large voltage (up to +/-90V) is created when the film moves back and forth. A simple resistor should get the voltage down to ADC levels. Can also be used for impact sensing or a flexible switch.

Comes with solderable crimp pins and a mass attached to the tip. This mass increases the sensitivity to motion.

Features:

• Flexible PVDF Piezo Polymer Film
• Wide dynamic range
• Laminated for higher voltage output
• 0.1" breadboard friendly leads