Tag Archives: Sensor

Smallest seismic sensor uses vibration spectral analysis

Graham Prophet @ eedesignnewseurope.com discuss about a new small seismic sensor from Omron:

Omron Electronic Components believes it has the world’s smallest class size seismic sensor, specifically designed to trigger the shutdown of potentially hazardous or easily damaged systems in the event of an earthquake.

Smallest seismic sensor uses vibration spectral analysis – [Link]

The First and Only Long-Term Stable Metal-Oxide Gas Sensor

At this year’s Sensor+Test 2017 in Nuremberg (May 30 – June 1), Sensirion AG, the expert in environmental and flow sensor solutions, introduces the SGP – the first and only long-term stable metal-oxide gas sensor.

The SGP gas sensor is based on Sensirion’s multi-pixel platform, which integrates four gas sensing elements into a very small 2.45 x 2.45 x 0.9 mm3 DFN package featuring a fully calibrated air quality output signal. The unprecedented combination of long-term stability and multi-pixel technology opens up new possibilities for environmental monitoring in smart home, appliances and Internet of Things applications. Thanks to its unique performance, the SGP allows for the first time the integration of metal-oxide gas sensors into mobile devices.

The First and Only Long-Term Stable Metal-Oxide Gas Sensor – [Link]

Increasing Battery Life With UB20M Voltage Detector

Engineers at the University of Bristol have developed a three terminal pico-power chip that can cut standby drain in sensor nodes – even compared with today’s low-power microcontrollers.

It does this by replacing the low duty-cycle sleep-wake-sleep pattern used on MCU-based sensor monitors, with ‘off’. A voltage detector powered by the sensor – there is no other power source –  starts the processor when the sensor produces a voltage.

At 5pA (20°C 1V), power draw from the sensor through the input/supply pin is so low that the chip can directly interface with high-impedance sensors such as antennas, piezo-electric accelerometers, or photodiodes. With so little current required, the chip does not collapse the sensor voltage.

“It will work from five infra-red diodes in series, powered from a TV remote control 5m away, or an un-powered accelerometer”, Bristol engineer Bernard Stark told Electronics Weekly.

Called UB20M, the only power it draws from the system is 100pA(max) leakage through its open drain output transistor. Input threshold is set at 0.6V.

Once the sensor presents greater than 0.6V to the input, the output FET turns on (RDSon~800Ω), and its low resistance can either be used to turn on a p-FET to power up a microcontroller, or can wake a microcontroller from sleep.

In an extreme application example, said the University, an earthquake detector could be held in sleep for years, until a tremor caused the chip to wake its host.

Despite its impedance and sensitivity, the device can withstand 20V on its input/supply pin, and it has ESD protection. Maximum output pin parameters are 5.5V 7mA. Output turn-on time is 0.25μs, while turn-off depends on load resistance and capacitance – typically 8μs with a 5MΩ load and 180μs with 100MΩ.

Because patents are pending, exactly how the chip works is not being disclosed. It has around 40 transistors, and is made on a 180nm CMOS process, is all Stark could say.

Samples are available – through a multi-project wafer deal with Europractice and IMEC, fabricated at AMS in Austria, and the University has created an evaluation board. Due to Europractice and IMEC going the extra mile, said Stark, samples are in SOT323-5 rather than clunky research packages.

The team cautions that anyone trying the chip will need to understand high-impedance circuits, as otherwise stray mains fields, for example, will trigger it continuously and the output transistor will remain on. Lengthy sensor connections should be avoided.

In general, the sensor has to be connected to the input/supply pin with enough parallel resistance to leak away stray charge and ensure the UB20M turns off.

“We are now working on ways of bringing other power drains such as data-capture, computation, and transmission, to within the nW-power budget of a sensor, completely eliminating batteries from sensor nodes,” said the University. “An example of this (right) is where power management with a few tens of nW quiescent is actively matching its input impedance to an 80MΩ energy harvester with 10 ms intermittent output pulses.”

UB20M data sheet and eval board details can be reached from this introductory web page, and there is an introductory video.

Source: Electronics Weekly

BMP380 – Ultra-miniature pressure sensor


Harry Baggen @ elektormagazine.com discuss about the new Bosch barometric pressure sensor BMP380.

At the CES, Bosch Sensortec unveiled the BMP380 barometric pressure sensor, the smallest and most accurate pressure sensor in their portfolio to date, with dimensions of 2x2x0.75 mm. The BMP380 is targeted at applications in drones, smartphones, tablets, wearables and other mobile devices for precise measurement of elevation changes.

BMP380 – Ultra-miniature pressure sensor – [Link]

DIY Breathalyzer Using Arduino UNO

Today I am going to discuss how to make a very simple DIY Breathalyzer using Arduino UNO and few external components. Ana Carolina designed this project as an instructable in instructables.com. This is a low-cost project and a useful one too. If you have no idea about what breathalyzer is, let me explain briefly: A breathalyzer is a device for estimating blood alcohol content (BAC) from a breath sample. Check the link given for more information.

Arduino Based Breathalyzer
Arduino Based Breathalyzer

Requirements:

  • Arduino Uno
  • MQ-3 Alcohol Sensor
  • 128×64 LCD (Liquid Crystal Display)
  • 7 × 330 Ohm Resistor
  • 7 × LEDs (1 Red, 2 Yellow, 3 Green and one other color)
  • Jumpers Wires
  • Breadboard
  • Soldering Iron (optional)
  • Solder Wire (optional)

Details:

This project is very simple. Here we are using an array of six LEDs and a 128×64 LCD to display the alcohol level. The presence of alcohol is sensed by an MQ-3 alcohol sensor and then analyzed by an Arduino board. We are using Arduino UNO in this project, but any model can do the job.

Three Green LEDs represent that alcohol level is OK and within the safe limit. Two Yellow LEDs are used to describe that safe limit is going to be reached, and you know it well why the Red LED is there. In fact, those LEDs are used just to give you a quick idea. If you want to know the exact value, the display is there for you.

You can tweak the program and re-calibrate the breathalyzer. But you must remember that breathalyzer doesn’t precisely measure your blood alcohol content, rather it estimates a value from the amount of alcohol in your breath.

Circuit:

Breathalyzer Circuit On Breadboard
Breathalyzer Circuit On Breadboard

You can make the circuit also on PCB or Veroboard. But for the prototyping purpose, the breadboard is the best choice. You can see how straight forward the connections are.

The Code:

Some part of the original code was in Portuguese. So I have translated it into English. Also, the original code shared by the author in instrucatbles.com is a buggy one. So, I recommend you to use my bug-free code instead of the original one.

Please note that you have to download and add the u8glib library in Arduino IDE beforehand. It is very important. You can either download the u8glib v1.14 library for Arduino directly or go to the site and choose what to download.

Follow the given steps to add a .zip library in your sketch: Open IDE and click on Sketch  Include Library  Add .zip Library. Now select the downloaded .zip library file. You needn’t unzip it.

When everything is done, verify and upload the code to Arduino.

Test It:

I must not recommend you to drink alcohol just for testing the breathalyzer. Rather get a towel and spray alcohol on it. Now hold the towel in front of the sensor. Move it back and forth to observe the change in reading. It may take a while for the breathalyzer to stabilize.

Consider watching the video for a better understanding:

RELATED POSTS

How to Set Up the DHT11 Humidity Sensor on an Arduino

circuitbasics.com has a new tutorial on how to interface DHT11 humidity sensor to Arduino board. Sample code is provided

Because of their low cost and small size, DHT11 humidity and temperature sensors are perfect for lots of different DIY electronics projects. Some projects where the DHT11 would be useful include remote weather stations, home environment control systems, and agricultural/garden monitoring systems.

How to Set Up the DHT11 Humidity Sensor on an Arduino – [Link]

Biometric sensor platform for wearables and IoT

A scalable development kit integrates ST SensorTile with Valencell’s Benchmark biometric sensor system to accelerate smart wearable and IoT product development. By Graham Prophet @ edn-europe.com

Valencell (Raleigh, North Carolina) is a company active in high-performance biometric data sensor technology; in a joint announcement with STMicroelectronics the two companies have disclosed an accurate and scalable development kit for biometric wearables that includes ST’s compact SensorTile turnkey multi-sensor module integrated with Valencell’s Benchmark biometric sensor system. Together, SensorTile and Benchmark comprise the most useful portfolio of sensors to support the most advanced wearable use cases, according to their designers.

Biometric sensor platform for wearables and IoT – [Link]

Ultrasonic parking sensor

An ultrasonic parking sensor project from Ch00ftech:

After electing to use the PING))) sensor exactly as directed, I needed to build the rest of my circuit.  I wanted to build something robust that would mount nicely on the wall of my dad’s garage.  Figuring that the sensor would likely need to be placed down low by the car’s bumper, I decided on a two-component design consisting of a small sensor and a large visible display that could be mounted at eye-level.

Ultrasonic parking sensor – [Link]

First Solid-State Multi-Ion Sensor for Internet-of-Things Applications By Imec & Holst Centre

At last week’s IEEE International Electron Devices Meeting (IEDM) in San Francisco (USA), imec, the world-leading research and innovation hub in nano-electronics and digital technology and Holst Centre debuted a miniaturized sensor that simultaneously determines pH and chloride (Cl-)levels in fluid. This innovation is a must have for accurate long-term measurement of ion concentrations in applications such as environmental monitoring, precision agriculture and diagnostics for personalized healthcare. The sensor is an industry first and thanks to the SoC (system on chip) integration it enables massive and cost-effective deployments in Internet-of-Things (IoT) settings. Its innovative electrode design results in a similar or better performance compared to today’s standard equipment for measuring single ion concentrations and allows for additional ion tests.

Sensors based on ion-selective membranes are considered the gold standard to measure ion concentrations in many applications, such as water quality, agriculture, and analytical chemistry. They consist of two electrodes, the ion-sensitive electrode with the membrane (ISE) and a reference electrode (RE). When these electrodes are immersed in a fluid, a potential is generated that scales with the logarithm of the ion activity in the fluid, forming a measure for the concentration. However, the precision of the sensor depends on the long-term stability of the miniaturized RE, a challenge that has now been overcome.

“The common issue with such designs is the leaching of ions from the internal electrolyte, causing the sensor to drift over time,” stated Marcel Zevenbergen, senior researcher at imec/Holst Centre. “To suppress such leaching, we designed and fabricated an RE with a microfluidic channel as junction and combined it with solid-state iridium oxide (IrOx) and silver chloride (AgCl) electrodes fabricated on a silicon substrate, respectively as indicating electrodes for pH and Cl-. Our tests demonstrated this to be a long-term stable solution with the sensor showing a sensitivity, accuracy and response time that are equal or better than existing solutions, while at the same time being much smaller and potentially less expensive.”

“We are providing groundbreaking sensing and analytics solutions for the IoT,” stated John Baekelmans, Managing Director of imec in The Netherlands. “This new multi-ion sensor is one in a series that Holst Centre is currently developing with its partners to form the senses of the IoT. For each sensor, the aim is to leapfrog the current performance of the state-of-the-art sensors in a mass-producible, wireless, energy optimized and miniaturized package.”

Source: imec

3-axis magnetic sensor claims highest sensitivity

Graham Prophet discuss about a new 3 axis magnetic sensor @ edn-europe.com:

Memsic (Andover, Massachusetts) has added the MMC5883MA 3 axis magnetic sensor. The newest member of MEMSIC’s Anisotropic Magneto Resistive (AMR) based Magnetic Sensor family, it provides the industry’s highest accuracy, lowest noise and lowest power consumption, all combined in an industry standard small LGA package, and addresses demands of industrial and drone applications.