Category Archives: Biometric and Human Activity

Human Presence Sensor

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Each channel within the sensor has a different field of view, so not only can it detect a human, but it can also tell which direction the person is moving.

Technical Description

The onboard AK9753(sensor name) is a digital sensor giving you a 16-bit digital value over I2C. Each of the four sensors outputs the IR current in pico-amps. A PIR reading can vary from roughly -200 (no human present) to 1500 when a human is detected standing in front of a given channel, but it varies due to environmental factors and other heat sources in view.

Limitations/Features

  1. Voltage: 1.7V to 3.3V
  2. Extremely low current: 100µA

Skill

3- Competent

Links

https://github.com/sparkfun/Qwiic_Human_Presence_Sensor_Breakout_AK9753

https://www.sparkfun.com/products/14349

Examples

https://github.com/sparkfun/SparkFun_AK975x_Arduino_Library/tree/master/examples

Open Camera

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The OpenMV M7 Camera is a small, low-power microcontroller board that allows you to easily implement applications using machine vision in the real world. The best part about the OpenMV is that it is not only capable of image capture, but also face detection, color tracking, QR code reading and plenty more. If you are looking for an economical camera module boasting multiple high-end features, look no further than the OpenMV M7!

Technical Description

The OpenMV can be programmed in high-level Python scripts (courtesy of the MicroPython Operating System) instead of C/C++. This makes it easier to deal with the complex outputs of machine vision algorithms and working with high-level data structures. You still have total control over your OpenMV M7 and its I/O pins in Python. We can easily trigger taking pictures and video on external events or execute machine vision algorithms to figure out how to control your I/O pins.

Parts

  1. 1x OpenMV M7 Camera
  2. 2x 8-pin Male Header
  3. 2x 8-pin Female Stackable Header

Limitations/Features

  1. Three I/O pins for servo control.
  2. Interrupts and PWM on all I/O pins (there are 10 I/O pins on the board).
  3. RGB LED and two high-power 850nm IR LEDs.
  4. A full-speed USB (12Mbs) interface to your computer; your OpenMV Cam will appear as a virtual COM port and a USB flash drive when plugged in.
  5. A μSD card socket capable of 100Mbs reads/writes, which allows your OpenMV Cam to record video and easily pull machine vision assets off of the μSD card.
  6. An SPI Bus that can run up to 54Mbs, allowing you to easily stream image data off the system to either the LCD shield, the WiFi shield or another microcontroller.

Skill

4-Experienced

Links

https://cdn.sparkfun.com/datasheets/Sensors/LightImaging/STM32F765VI.pdf

https://www.sparkfun.com/products/14985

 

Stereo Camera

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Technical Description

The EX8029 Stereo Camera from eYs3D is a depth-map imager controller and patterned IR illuminator capable of both color and point map output modes. Thanks to its dual cameras, this Stereo Camera is ideally used in applications involving motion and gesture control, field mapping, and 3D scanning. The best part about this module is the fact that it has been designed to be as straight forward and easy to use as possible for a stereo camera. Simply plug in the included USB 3.0 cable download the required files and start seeing things through the eyes of your new camera.

Limitation/Features

  1. IR pattern Illuminator Wavelength: 850nm +/-10 nm
  2. IR pattern Illuminator Number of Features: >10,000
  3. Lens: 1LS1022G by AOET
  4. Image Sensor: OV9714 by OVT
  5. USB Bus Power: 5V/900mA by USB3.0; 5V/500mA by USB2.0
  6. PC Connection: USB3.0 & USB2.0
  7. Power Voltage: 5V
  8. Operating Current With Patterned IR Illuminator: ≦350mA
  9. Operating Current Without Patterned IR Illuminator: ≦280mA
  10. Suspend Current: ≦15mA

Skill

4-Experienced

Links

https://www.sparkfun.com/products/14726

 

Magnetic Imaging Tile

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Cost 149.95$

Technical Description

The Magnetic Imaging Tile uses an array of 64 hall effect sensors to convert magnetic fields to the visual spectrum. This allows the user to see magnetic fields in real time. As is to be expected, there are caveats: the magnetic sensors used on the tile are some of the most sensitive on the market but being within 1 to 2 centimeters of the tile is required to get a good image.

Limitation/Features

  1. Powered with 3.3V to 5V
  2. Uses approximately 150mA during sensing at 3.3V
  3. Size: 52x34mm
  4. Boards can be tiled next to each other to increase field size with a one ‘pixel’ gap between boards.

Skill

4-Experienced

Links

https://www.sparkfun.com/products/14652

https://github.com/sparkfunX/Magnetic_Imaging_Tile

RFID Button

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Technical Description

This is a simple, thumbnail-size RFID tag. These tags are great for sensing the presence, identification, etc., and they’re small so they can be easily sewn into clothing or inserted into enclosures. Each tag comes with a unique 32-bit ID code and is not reprogrammable. The carrier frequency of this tag is 125kHz, so it works great with our ID-2, ID-12, and ID-20 RFID readers.When this was tested this RFID tag with one of our ID-12 readers and measured a maximum read distance of about 32mm.

Limitation/Features

  1. 32-bit unique ID – non-reprogrammable
  2. 125kHz read frequency
  3. EM4001 ISO based RFID IC
  4. Manchester encoding
  5. Diameter: 16mm
  6. Thickness: 1.85mm

Skill

2-Rookie

Links

https://www.sparkfun.com/products/9417

 

GPS Receiver

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Technical Description

The GP-20U7 is a compact GPS receiver with a built-in high performances all-in-one GPS chipset. The GP-20U7 accurately provides position, velocity, and time readings as well as possessing high sensitivity and tracking capabilities.

Limitation

The following are the features

  1. 56-Channel Receiver (22 Channel All-in-View)
  2. Sensitivity : -162dBm
  3. 2.5m Positional Accuracy
  4. Cold Start: 29s (Open Sky)
  5. 40mA @ 3.3V

Skill

2-Rookie

 

Links

https://www.sparkfun.com/products/13740

Infrared Array Breakout

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“It’s like having a thermal camera, just in a lower resolution. To make it even easier to get your low-resolution infrared image, all communication is enacted exclusively via I2C, utilizing our handy Qwiic system”

Cost: $40.95

Technical Description

The on-board AMG8833 Grid-EYE possesses an accuracy rate of ±2.5°C (±4.5°F) with a temperature range of 0°C to 80°C (32°F to 176°F). Additionally, this IR “camera” board can detect human body heat at about 7 meters or less (that’s about 23 feet) and has a frame rate of 10 frames a second to one frame a second. It is important to point out that while this version of the Grid-EYE is the high-performance type with a high gain, it is only 3.3V tolerant. IE: Don’t try to operate it at 5V (you won’t have a very good time).

Applications

Can detect human body heat at about 7 meters

Limitations

It has very specific features which are the following :

  1. Operating Voltage(Startup): 1.6V – 3.6V
  2. Operating Voltage(Timekeeping): 1.5V – 3.6V
  3. Current Consumption: 4.5 mA
  4. 8×8 Thermopile Array
  5. Temperature Range: 0°C to 80°C (32°F to 176°F)
  6. Accuracy Rate: ±2.5°C (±4.5°F)
  7. Human Detection Distance: 7m or less (22.966ft)

Skill

3-Competent

Links

https://www.sparkfun.com/products/14607

https://github.com/sparkfun/Qwiic_GRIDEye

Sample

https://github.com/sparkfun/SparkFun_GridEYE_Arduino_Library

Infrared (IR) break-beam sensor

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Infrared (IR) break-beam sensors are a simple way to detect motion. They work by having an 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.

Technical Description: 

Compared to PIR sensors, breakbeams are faster and allow better control of where you want to detect the motion. Compared to Sonar modules, they’re less expensive. However, you do need both emitter and receiver on opposite sides of the area you want to monitor.

Limitations:
The 5mm IR version works up to 50cm / 20″, so we need a lot of them to measure open space.

Skill:
Easy

Sample Sensor:
IR Break Beam Sensor:
https://www.adafruit.com/product/2167

Sample Exercise:

https://learn.adafruit.com/ir-breakbeam-sensors

 

Pressure mats

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Pressure sensor pads are electronic devices that capture physical force contact to generate some sort of a response. There is a truly endless amount of applications for pressure sensor pads, ranging from an input mechanism in a human-machine interface (HMI), a method to capture intruders in a force-sensitive security system, and beyond.

Technical Description: 

They have a force range of 0-222 N (0-50 lb), specified with Tekscan electronics. The model is linear through a much lower range of 0-22N (0-5 lb), and is capable of measuring loads up to 44,482 N (10,000 lb).*

The dynamic range of this square force sensor can be modified by changing the drive voltage and adjusting the resistance of the feedback resistor

Limitations:
Expensive

Skill:
Easy

Sample Sensor:
FlexiForce A502 Sensor:
https://www.tekscan.com/products-solutions/force-sensors/a502

Sample Exercise:
https://www.tekscan.com/blog/flexiforce/how-create-pressure-sensor-pad

 

BioSensor – DNA Sensor

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A DNA biosensor is a sensing device that converts the presence of a target DNA into a detectable electrical signal. It consists of two parts, one is the identification component, the DNA probe, and the other is the transducer. The protagonist of the recognition component is used to sense whether the sample contains the target DNA to be tested; the transducer converts the signal perceived by the recognition component to observe the recorded signal. Usually, a single-stranded DNA is solidified on a transducer, and hybridized by DNA molecules to identify another DNA containing a complementary sequence to form a stable double-stranded DNA, and the target DNA is subjected to conversion by sound, light, and electric signals. Detection. The principle of DNA biosensor is that a double-stranded DNA formed by hybridization of a single-stranded DNA molecule with a known nucleotide sequence immobilized on the surface of a sensor or transducer probe to another complementary ss-DNA molecule will exhibit a certain The physical signal is finally reflected by the transducer. However, DNA molecules are very small and fragile

Application:

  1. Environmental: water environment monitoring and atmospheric environment monitoring.
  2. Military medicine: effective measure against biological weapons, monitor a variety of bacteria, viruses and their toxins, such as Bacillus anthracis, Yersinia pestis.
  3. Forensic science: DNA identification, paternity testing, etc.

One Example:

Illustration of graphene-based SNP detection chip wirelessly transmitting signal to a smartphone.

BioSensor chip that can detect a type of genetic mutation known as a single nucleotide polymorphism (SNP) and send the results in real time to an electronic device.

 

Skill level required for electronics and coding: Expert