Tag Archives: accelerometer

Bosch BMA400 – Did you thought accelerometers couldn’t get any better?

Accelerometers are used in almost all fields, and they have been growing in popularity in IoT and wearables. Nowadays, those devices require a of energy, and because of this, they need to be constantly charged or batteries need to be constantly changed which causes users to lose interest, or to be limited by this problem. Size might be a problem too because some MEMs (micromechanical systems) acceleration sensors are too big to be implemented in everyday portable objects. In June 2018, Bosch will unveil their BMA400, a sensor that extends battery life and has a huge range of capabilities in a small size.

BMA400 is capable of measuring tilt, orientation, tap/double tap, and step counting (with activity recognition) using a low- noise measurement of accelerations in three perpendicular axes. Additionally, the device only uses 10% of the energy current comparable devices use which makes it useful for applications where charging is impossible. For example, this device could be used for package tracking over long distances, saving power by putting itself on sleep mode until something happens (the package is mishandled) which could compromise the quality of the product inside the package.

Other applications include home automation (automatic air conditioning that considers status (open or closed) of windows and doors), security (burglar detection), and sports. The BMA400 includes an activity detection function that can differentiate between walking, running, and standing. All this could be applied into wearables, and because of its size it could be a game changer in hybrid smartwatches (traditional watch with added smarts in a discrete way).

BMA400 measure only 2 mm x 2 mm x 0.95 mm, and device data can be retrieved over longer intervals (FIFO buffer of 1kB). Other specifications include:

  • 12-bit digital resolution
  • Output data rate (ODR) of 12.5 Hz to 800 Hz
  • Supply voltage of 1.71 V up to 3.6 V

Complete list of specifications can be found in the official website.

This improvements in an already widely used technology could result in advances in thousands of different devices, and in the implementation of this sensor in devices where it couldn’t be fitted before. Improving battery means improving product usability which results in happy users who can now use their device for longer periods of time. Also, makers and hobbyists could now apply this technology to new devices using the increased battery life as an advantage.

 

[Source]

SODAQ ONE board – GPS + LoRa + Solar charger

This is the third generation of our succesful SODAQ ONE board. It is equipped with a solar charge controller and runs on a LiPo or a permanent battery. It has the Ublox Eva 8M GPS module which is not only miniature but with it’s assisted GPS feature it can get a fix within seconds. We’ve now added an extremely low power Accelerometer/Magnetometer. This gives the board a nifty feature where it can stay in (deep) sleep mode until it moves. An essential feature for developing low power devices.

Let’s imagine you want to develop a bicycle tracker using the SODAQ ONE. You would like to track the position of the bike, but only when it has moved. This is possible if you keep the device in deep sleep until it detects motion. If the motion continues for a while, the bicycle may have changed position so only then the GPS will switch on to get a new reading and send this location over the LoRa network. Efficient right? This system will allow you make most efficient use of your battery capacity by only using the GPS when really needed, essentially increasing the battery life of your system.

SODAQ ONE board – GPS + Solar charger board – [Link]

Iota V2 – Gyroscope Sensor in tiny dimensions

De Martin Cote @ kickstarter.com designed v2 of his gyroscope sensor that is able to track movement on 3-axis. The new board is smaller, lighter, cheaper and has PPM output to connect on your RC remote control. He writes:

Here is the evolution of my successful Gyroscope Sensor. Now smaller, lighter, cheaper and with optional PPM output.

Even more perfect for FPV head tracking, robotics, movement control and why not video games. Based on ATmega328P microcontroller, the 3 axis motion sensor gyroscope allows you to track the movement of the head or arm and replicate it to servos. For Do It Yourself (DIY) home project lover who dreams of doing a head tracking system FPV themselves cheaply.

This system has been specially designed for DIY in electronics or robotics for students to explore electronics or who want their own system, but are less comfortable with advanced programming of accelerometers. You can use one or more axes (X, Y, Z) independently. According to your needs.

Iota V2 – Gyroscope Sensor in tiny dimensions – [Link]

Using an MMA7455 accelerometer with an ESP32 board

by shedboy71 @ microproducts.net discuss how to use MMA7455 accelerometer with ESP32 board. He writes:

The MMA7455L is a Digital Output (I2C/SPI), low power, low profile capacitive micromachined accelerometer featuring signal conditioning, a low pass filter, temperature compensation, self-test, configurable to detect 0g through interrupt pins (INT1 or INT2), and pulse detect for quick motion detection. 0g offset and sensitivity are factory set and require no external devices. The 0g offset can be customer calibrated using assigned 0g registers and g-Select which allows for command selection for 3 acceleration ranges (2g/4g/8g). The MMA7455L includes a Standby Mode that makes it ideal for handheld battery powered electronics.

Using an MMA7455 accelerometer with an ESP32 board – [Link]

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.

Flight controller unit evaluation board for drones

The STEVAL-FCU001V1 board from ST is designed to support quadcopter drone designers with the latest solutions for motor control, sensors and and microcontroller.

A complete sample FW project allows the designer to begin flying small and medium size quadcopters (with brushed or brushless DC motors) immediately and evaluate the performance of the IMU sensors under real flight conditions. The FCU can be controlled by a standard external remote controller (PWM input interface) or by a smartphone or tablet through the Bluetooth low energy module present on board (CE, FCC, ARIB, BQE certified). Magnetometer and pressure sensors are also embedded to support 3D navigation applications. SWD, I²C and USART connectors are available for FW development and debugging, and to support additional external sensors or RF modules.

Key Features

  • Compact Flight Controller Unit evaluation board complete with sample firmware to a small and medium size quadcopter
  • Lipo 1-cell battery charger on-board
  • Possibility to drive directly 4 DC brushed motors through low voltage on-board MOSFET or alternatively use external ESC for DC brushless motor configuration
  • Main components:
    • STM32F401 – 32-bit MCU with ARM® Cortex®
    • LSM6DSL – iNEMO intertial module: 3D accelerometer and 3D gyroscope
    • LIS2MDL – High performance 3D Magnetometer
    • LPS22HD – MEMS pressure sensor: 260-1260hPa absolute digital output barometer
    • SPBTLE-RF – Very low power module for Bluetooth Smart v4.1
    • STL6N3LLH6 – N-channel 30 V, 6 A STripFET H6 Power MOSFET
    • STC4054 – 800 mA Standalone linear Li-Ion battery charger
  • RoHS compliant

MEMS — A 22-billion-dollar-worth industry by 2018

Thanks to Micro-Electro-Mechanical-Systems MEMS technology, which will be a 22-billion-dollar-worth industry by 2018, our mobile phones are equipped with accelerometers and gyroscopes so they know the direction and rotate our mobile screen as needed. The applications of MEMS had expanded a lot in various fields like: energy harvesting using piezoelectric effect, microphones, gyroscopes, pressure sensors, accelerometers and many more. Moreover, this micro-level technology is going to be nano-level with Nano-Electro-Mechanical-Systems NEMS.

Image is adapted from HowToMechatronics.com YouTube channel

The basic idea behind MEMS is about having moving parts inside the silicon chip. Accelerometers for example, one of the most famous applications of MEMS, sense the acceleration by measuring the change of the capacitance C1, C2 between a moving part/mass and fixed plates. So when acceleration is applied in a particular direction it can be detected and measured.

Image is adapted from engineerguy YouTube channel

The amazing “How a smartphone knows up from down” video presented by Bill Hammack (engineerguy) can demonstrate in a clear way the principle of MEMS.

Last but not least, MEMS has applications in medical and health related technologies like Lab-On-Chip. LOCs can integrate a laboratory function in a single chip. So MEMS may not only solve technical problems, but they may also play an important role in solving problems in human health field.

“Genotyper” device. via NIAID

Tri-axis sensor embeds pedometer

Susan Nordyk @ edn.com discuss about the Kionix’s accelerometer with integrated pedometer.

The K126 16-bit tri-axis digital accelerometer from Kionix integrates a step detector and step counter, yet minimizes power consumption. Housed in a tiny 2×2×0.9-mm LGA package, the K126 offers user-selectable g ranges of ±2 g, ±4 g, and ±8 g and output data rates of up to 25.6 kHz.

Tri-axis sensor embeds pedometer – [Link]

Accelerometers for vibration measurements & wireless condition monitoring

Graham Prophet @ eedesignnewseurope.com discuss about two new MEMS accelerometers from Analog Devices:

Analog Devices (ADI) has added two devices to its low noise, low drift, low power, three-axis MEMS accelerometers. The low noise performance over high frequencies provided by the ADXL356 and ADXL357 MEMS accelerometers delivers high resolution vibration measurements that enable the early detection of machine failure in condition monitoring applications.

Accelerometers for vibration measurements & wireless condition monitoring – [Link]

3-axis accelerometer performs wake-up in consumer designs


Kionix (Ithaca, New York), part of the Rohm Group, has added the KXTJ3 3-axis low-cost accelerometer that offers the performance of a more expensive accelerometer in a 2 x 2 x 0.9 mm form factor. By Graham Prophet @ eedesignnewseurope.com

The company presents the device as a high performance and reliable accelerometer in a package that is sized and priced to be embedded in anything and everything, from toys, wearables, remote controls to the SmartHome and IoT.

3-axis accelerometer performs wake-up in consumer designs – [Link]