Tag Archives: camera

MediaTek Sensio, is a 6-in-1 biosensor module for smartphones

Smartphones in recent times have contributed to the growth of the medical sensing industries with a major success in the usage of a smartphone camera and flash to detect heart rate. Specialized Apps installed on the phone can use the phone inbuilt camera and flash to read an individual heart rate with high accuracy but nothing else in the space of health monitoring. Sensio is a biosensor that will allow smartphones to track six different health metrics, a big game changer in the smartphone and medical industry.

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The Taiwan-based mobile chipset maker MediaTek has recently introduced MediaTek Sensio, the Industry’s first 6-in-1 biosensor that will turn smartphones into a personal health companion. Sensio will come as an embedded module for smartphones which make it possible to easily check and monitor one’s physical wellness.

The MediaTek Sensio MT6381 will allow smartphones to track a user’s heart rate, blood-pressure, heart-rate variability, peripheral capillary oxygen saturation, ECG (Electrocardiography) and photoplethysmography (PPG). It works using an integration of hardware and software in order to measure all these health data in about 60 seconds, as claimed by MediaTek. The company will have an app that can track all of this data and have it accessible to the user and also stored in the cloud.

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The MediaTek Sensio module uses a combination of LEDs (light emitting diodes) and a light-sensitive sensor to measure the variations in red and infrared light from the user’s fingertips. The module is able to measure the ECG and PPG levels by creating a closed loop between the user’s heart and the biosensor which is made possible when the user touches the electrical sensors and electrodes on the device.

The following are the features of the MediaTek Sensio:

  • Heart Rate – Measures heart beats per minute.
  • Heart Rate Variability – Measures variation in the time between heartbeats.
  • Blood Pressure Trends – Measures blood pressure trends to help users see data over a period of time.
  • Peripheral Oxygen Saturation (SpO2) – Measures the amount of oxygen in the blood.
  • Electrocardiography (ECG) – Measures the electrical activity of the heart over a period of time and displays it in graph form.
  • Photoplethysmography (PPG) – Measures the change in volume of blood.

The MediaTek Sensio module includes the following:

  • Integrated R and IR LEDs for reflective PPG measurement + 1 -channel ECG analog front -end.
  • Compact 6.8 mm x 4.93 mm x 1.2 mm OLGA 22-pin package.
  • Total External BOM: 4caps + 2 electrodes
  • I2C / SPI digital interface.

“Giving people the power to access their health information with a smartphone is a major step in making the world a healthier place,” said Dr Yenchi Lee, Sr. Director of Product Marketing for MediaTek’s wireless business. The MediaTek Sensio is expected to be available beginning in early 2018.

L20G20IS Gyroscope: The secret behind the perfect picture

STMelectronics introduces a super tiny two-axis gyroscope (L20G20IS), a Micro-Electro-Mechanical system (MEMS) designed for the optical image stabilization for Smartphones with less energy consumption compared to its predecessor (L2G2IS).

A gyroscope, or gyro for short, adds an additional dimension to the information supplied from the accelerometer by tracking rotation or twist. An accelerometer measures linear acceleration of movement, while a gyro on the other hand measures the angular rotational velocity.

The gyro and the accelerometer work together to detect the rotation of phone and other features like tilting of phone while playing racing games, enhancing the overall gaming experience or in this case, achieving optical image stabilization.

The L20G20IS ultra-compact square gyro uses 25% less surface to shrink camera module size, simplify circuit design and allowing development of thinner devices. The gyro fixes the thin substrates deformations resulted by smartphone moves to ensure consistent measurements for image stabilization.

Features:

  • ±100 dps / ±200 dps full-scale range
  • 5 degree phase delay · 3.8 mdps/√(Hz) rate noise density
  • Wide supply voltage range: 1.7 V to 3.6 V
  • Low-voltage compatible IOs
  • 3- and 4-wire SPI digital interface
  • Embedded temperature sensor
  • Embedded self-test
  • Integrated low-pass filters with user-selectable bandwidth
  • Power-down and sleep modes for smart power saving
  • ECOPACK®, RoHS and “Green” compliant
  • Volume (2.0 x 2.0 x 0.7)mm
  • Zero-rate Level: 0.03dps/°C (range: -20°C to 75°C)

Also L20G20IS includes a sensing element and an IC interface capable of providing the measured angular rate to the application through an SPI digital interface. It is compatible with single- or dual-camera modules and is available now in the 12-lead 2mm x 2mm LGA package.

Zero-rate level: This value indicates “the deviation of an actual output signal from the ideal output signal if no acceleration is present”, or more clearly the output value that will be generated when there is no movement on the device. This is very important for the phone, it needs to know when it is not moving to be able to stabilize the images with the appropriate values.

Results

Smaller but more efficient gyroscope! The L20G20IS boots 30% faster (in less than 70ms) consuming just 1.4mA (50% less of current than usually). Although, the temperature can affect the sensitivity and the zero-rate level of the gyro, producing wrong measurements for image stabilization by the phone. However, the L20G20IS device has a integrated temperature sensor to guarantee sharper images to the users even with long exposure times.

The smart-camera software saves even more battery with the power-down and sleep modes. Another improve is the  suppression ratio of 6dB, it gives outstanding optical correction to banish camera shake from smartphone photography.

Source:  Micro-Electro-Mechanical Systems (MEMS). ST is a world leader in MEMS devices for mobile applications, with more than 900 MEMS-related patents and patent applications worldwide.

Apertus AXIOM Professional Digital Cinema Camera is open source

Apertus AXIOM Beta is a professional digital cinema camera built around free open source software and hardware. AXIOM Beta is the latest version powered by MicroZed development board based on Xilinx Zynq 7020 ARM + FPGA SoC, and running Arch Linux ARM. The camera will run Arch Linux ARM on MicroZed board, support common network protocols (SSH/FTP/SCP/etc), and be configurable via a web interface. It has many interesting specification as listed below, however audio recording is not currently supported. Many more software and hardware details can be found in their Wiki.

AXIOM Beta developer kit hardware specifications:

  • “Linux” Board – Xilinx Zynq 7020 based MicroZed board
  • Beta Main Board – Hosts two external medium-speed shield connectors and two high-speed plugin module slot connectors.
  • Image Sensor – 12MP CMV12000 (Used for research and development) via CMV12K ZIF Sensor Board
  • Lens Mount Passive E-mount
  • Ports – USB / USB UART / JTAG / Gigabit Ethernet
  • Modules and Shields
    • Single HDMI Full HD (4:4:4) output at up to 60 FPS
    • Dual 6G SDI output (in development)
    • 3x PMOD debug module
    • LED matrix debug module
    • Genlock, Trigger, Timecode, LANC shields (in development)
    • 4K Displayport/HDMI (in development)
  • Power Supply – 5V/5A via power adapter board; Other voltages provided via Beta Power Board
  • Dimensions -111.76 x 74 x 65.1 mm (devkit)
  • Weight – 319 grams (devkit)

A Compact Camera Using Raspberry Pi A+ And Adafruit TFT Display

PiJuice at instructables.com designed an interesting compact camera project with raspberry pi. Raspberry Pi A+ is used in this project as it is the cheapest and smallest available Raspberry Pi. The real challenge in this kind of portable Pi projects is powering the Raspberry Pi. This issue is solved using PiJuice—an all in one battery module for the Raspberry Pi.

Required Parts

Required parts to make Raspberry Pi compact camera
Required parts to make Raspberry Pi compact camera

Set Up The Raspberry Pi

Download the latest version of the Raspbian image from the Raspberry Pi Website and burn it on your blank SD card. You can use win32DiskImager or your favorite software to get the job done. Now, you need to install the drivers for the TFT screen by running the DIY installer script, explained on the Adafruit page. Connect the TFT to the Raspberry Pi, attach the PiJuice with a charged battery, and switch it on. Your screen now should display boot up messages.

Connect The Camera

Insert the ribbon cable of your camera module properly ensuring that the blue side of the ribbon is facing away from the HDMI port. Now, go to the terminal and type the following command,

sudo raspi-config

Enable the camera in the menu and then reboot the Pi. The camera should work properly after a successful reboot. To test the camera, enter the following command:

raspistill -o pic.jpg

This will take a snap and save it in the /home/pi directory.

Connect A Push Button

You need a push button to simulate a shutter action. Locate the pin 17 on the GPIO breakout on the top of the TFT screen. Now, solder two wires to the terminals of the push button. You can either solder a right angle header to the pin 17 or you can directly solder one wire from push button to that pin. There is a pad labeled WP on the board. It is actually connected to the ground. Solder another wire from the push button to this pad.

Install And Test The PiCam Software

To install the software, the Raspberry Pi must be connected to the internet. Enter the commands given below to download and install PiCam.

sudo apt-get install git-core
sudo mkdir PiCam
cd /PiCam
git clone git://github.com/pijuice/PiCam.git

Once the software has been downloaded, navigate to the PiCam directory using the command:

cd /picam

You can run it by typing the command:

sudo python picam.py

Now, you can take pictures by simply pressing the push button. Once the button is pressed the picture will be taken. Once the captured image gets loaded, your photograph will be displayed.

Taking photograph with Raspberry Pi compact camera
Taking photograph with Raspberry Pi compact camera

Conclusion

Your Raspberry Pi camera is ready now. If you want to make it even more compact as well as portable, grab the official laser-cut compact camera case from the Kickstarter page by pre-ordering a Maker Kit. You can also build your own simple chassis for housing the camera.

Pi Desktop Case – include peripherals too

The ‘Pi Desktop’ kit from element14 offers some great features like Wi-Fi, Bluetooth, a real-time clock, an interface for an mSATA-SSD hard drive, an optional camera, heat sink, a neat power switch and of course the sleek black case. [via]

The Raspberry Pi is a well designed, powerful and inexpensive board, but not a complete computer. Some distributors know you need more than just a plastic case and a mains-adapter power supply (or USB cable). The ‘Pi Desktop’ kit from element14 contains everything you need and more, turning your RPi into a fully fledged computer.

Pi Desktop Case – include peripherals too – [Link]

Fast Single-Pixel Camera

Compressed sensing is an new computational technique to extract large amounts of information from a signal. Researchers from Rice University, for example, have built a camera that can generate 2D-images using only a single light sensor (‘pixel’) instead of the millions of pixels in the sensor of a conventional camera.

This compressed sensing technology is rather inefficient for forming images: such a single-pixel camera needs to take thousands of pictures to produce a single, reasonably sharp image. Researchers from the MIT Media Lab however, have developed a new technique that makes image acquisition using compressed sensing fifty times more efficient. In the example of the single-pixel camera that means that the number of exposures can be reduces to several tens.

One intriguing aspect of compressed sensing is that no lens is required – again in contrast with a conventional camera. That makes this technique also particularly interesting for applications at wavelengths outside of the visible spectrum.

In compressed sensing, use is made of the time differences between the reflected light waves from the object to be imaged. In addition, the light that strikes the sensor has a pattern – as if it passed through a checkerboard with irregular positioned transparent and opaque fields. This could be obtained with a filter or using a micro-mirror array where some mirrors are directed towards the sensor and others are not.

The sensor each time measures only the cumulative intensity of the incoming light. But when this measurement is repeated often enough, each time with a different pattern, then the software can derive the intensity of the light that is reflected from different points of the subject.

Source: Elektor

Raspberry Pi Security System

MWAGNER @ hackmypi.com build a security camera based on Raspberry Pi:

A family member asked me to put a camera in our garage recently, and immediately I decided to use a Pi Zero. Back when I was interviewing for my current job, I was dabbling with the idea of making a wireless, battery powered IP camera that I was going to attach to my dog, and get some cool footage of my dog running around.

Raspberry Pi Security System – [Link]

Building A Tiny Portable Time-lapse Camera

Using a mini spy camera module, Ruiz Brothers had built a tiny portable camera that is used to take time-lapse videos and for all sorts of photo based projects.

This project consists of these parts with an estimated cost of $39:

The mini spy camera module has an integrated driver and is easy to use without an Arduino or Raspberry Pi. The camera sensor can take 1280×960 photos and captures video at 480p. The module uses a microSD card to store data and it has a maximum support of 32GB. For a higher image quality and adjustable settings, you can use other camera modules such as the Wearable Raspberry Pi Zero Camera.

To take a time-lapse, an intervalometer remote control is needed to trigger the camera for capturing a photo within a constant interval. The Adafruit Trinket microcontroller is used here, and you can also make your own following this guide.

The circuit will be powered by a 3.7V 100mAh Lithium Ion battery via JST connection. The battery plugs directly into the Trinket Backpack, which allows the recharging over the microUSB port on the Trinket.

The circuit is connected as shown in the diagram; the slide switch to Lipoly backpack, VCC from camera to 5V on Trinket, GND from camera to GND on Trinket, BAT from Lipo backpack to BAT on Trinket, G from Lipo backpack to GND on Trinket, and 5V from Lipo backpack to USB.

The code is very simple and can be uploaded to the controller using the Arduino IDE. The setup loop will initialize the pins, and the loop will turn on and off the trigger with a chosen delay.

int trig = 0;
int led = 1;
 
void setup() {                
  // initialize the digital pins as output.
  pinMode(led, OUTPUT);
  pinMode(trig, OUTPUT);         
 
  digitalWrite(led, HIGH);  
  digitalWrite(trig, HIGH); 
}
 
// Hold HIGH and trigger quick (<250ms) LOW to take a photo. Holding LOW and trigger HIGH starts/stops video recording
 
void loop() {
  digitalWrite(trig, LOW);   
  digitalWrite(led, HIGH);
  
  delay(50);               
 
  digitalWrite(trig, HIGH);    
  digitalWrite(led, LOW);   
  
  delay(5000);               
}

The case in 3d printed, the design with a detailed description and the full making guide is available here. This video is showing how to make this tiny camera and how it works.

facetVISION: Compound Eyes for Industry and Smartphone

Researchers at the Fraunhofer Institute for Applied Optics and Precision Engineering IOF have developed a process that makes the production of a two-millimeter flat camera possible. Similar to the eyes of insects, its lens is partitioned into 135 tiny facets. The researchers have named their mini-camera concept facetVISION, following nature’s model. This mini-camera has a thickness of only two millimeters at a resolution of 1 megapixel.

facetVISION compound eye: First prototype
facetVISION compound eye: First prototype

All 135 small, uniform lenses are positioned close together, similar to the pieces of a mosaic. Each lens receives only a small section of its surroundings. The newly developed facetVISION technology aggregates the many individual images of the lenses to a whole picture. Finally, this technology should obtain a resolution of 4 megapixels. This is certainly a higher resolution compared to latest cameras in industrial applications like robot technology or automobile production.

The compound eye technology is also suitable for integration into smartphones. The lens of a modern smartphone must be at least 5 millimeters thick in order to capture a sharp image. The manufacturers of ultrathin smartphones are facing this challenge since the camera lens is thicker than the housing of the phone. But, this new technology can reduce the thickness to around 3 millimeters without compromising picture quality. Andreas Brückner, the project manager at the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena, says:

It will be possible to place several smaller lenses next to each other in the smartphone camera. The combination of facet effect and proven injection molded lenses will enable resolutions of more than 10 megapixels in a camera requiring just a thickness of around three and a half millimeters.

The researchers also explained how this camera can be used in medical engineering as optical sensors to examine blood. The facetVISION has many other applications like checking image quality in a printing machine, parking camera in cars or in industrial robots to prevent collisions between human and machine.

Mass production of facetVISION is possible
Mass production of facetVISION is possible

Under the leadership of Andreas Brückner, the researchers have already demonstrated that facetVISION is suitable for mass production. So, keep waiting and maybe you will purchase a new smartphone equipped with a facetVISION compound eye in not so distant future.

Dintervalometer, A Custom Made Intervalometer For DSLR Cameras

If you want to take a timelapse with your camera, it may be helpful to use an intervalometer. It is an attachment or facility on a camera that operates the shutter regularly at set intervals over a period, in order to take timelapse series or take pictures after a set delay.

Daniel Knezevic had developed a custom made intervalometer for DSLR cameras. Dintervalometer (Deni’s intervalometer) enables cameras to shoot time lapses and allows shutter speeds longer than the 30s.

The Dintervalometer is built with an Atmega328P clocked at 10MHz, a PCD8544 84×48 pixel monochrome LCD display with a backlight, a 3.5mm male jack connector, and two tactile push buttons all combined together on a small PCB.

Dintervalometer Features

  • Intervalometer: It is used for time-lapse photography. It controls how often, how long and how many shots are taken.
  • Bulb mode: It allows to take time exposures longer than 30s.
  • Backlight
  • Charging via USB

The Display & Backlight

The PCD8544 LCD display can be powered using 3V3 and it draws very small amounts of power (around 200uA) making it extremely good for use in battery powered devices. It is typically used in Nokia 5110/3310 phones, and it interfaces to microcontrollers through a serial bus interface (SPI).

A custom made backlight were designed to allow using the Dintervalometer in the dark without an additional lamp. It operates like a backlight of a cell phone: it is active for 10 seconds when the user presses a button or the Dintervalometer finishes some job.

The backlight consists of these materials:

  • A sheet of white paper
  • A piece of transparent plastic
  • A double-sided tape

The first layer of the backlight is a sheet of white paper. Its main function is to reflect the light of the LEDs. Then it comes the piece of transparent plastic. The top of the plastic is sanded with a fine sandpaper to diffuse the light. Finally, the LCD comes on the top. The layers are glued together with a double-sided tape.

Powering & Charging

Dintervalometer’s circuit is powered using a LiPo battery and a very low drop 3V3 voltage regulator (TPS79933). A MAX1555 Li+ battery charger IC is used to charge the battery, which also can be powered via USB.

To prevent the over-discharge of the LiPo battery, Dintervalometer monitors and measures the battery voltage every 60 seconds. The user can always see the current status of the battery on the LCD. When the battery reaches the critical voltage, a “Low battery” notification will be shown, then the device will turn off.

The voltage measuring process is done using a voltage divider and AVRs internal 1V1 voltage reference.

The following equation is used to measure the battery voltage in mV, with the known values R2=10k, R3=3k3, Vref=1100mV, ADCres=1024.

Controlling The Camera

Using the 3.5mm male jack connector, the Dintervalometer will trigger the camera to focus and to take a picture. The jack consists of three wires: ground, focus and shutter.

To focus the camera, the focus wire has to be connected to the ground. To release the camera both wires have to be connected to the ground. Dintervalometer is tested with Canon EOS 700D. It has a jack plug for remote shuttering.

The Software

The software is written in C and compiled with avr-gcc. It is divided into 6 logical modules:

  • TIMER: Initializes Timer1 and provides an interrupt based delay function.
  • BATTERY: Initializes ADC to read the battery voltage.
  • BACKLIGHT: Functions are used to control the backlight (initialize and update).
  • GPIO: Initializes IO ports for buttons, camera output, battery charger status indication, auto cut off control output.
  • LCD: It represents the pcd8544 LCD driver, it is reusable code for other projects. The driver provides the API to initialize, control, and print text on the LCD.
  • STATE: The state machine is implemented by using function pointers. Each menu state has three basic operations; show data on LCD, wait for user input, update backlight and battery status, and handle button presses/holds.
State Machine Diagram

Dintervalometer Sources

This project is published on hackady.io. Daniel had shared all the source designs and scripts online, so you can get it on its Github repository.