Tag Archives: electronic design

Tyre pressure monitoring system using Bluetooth Low Energy

A tyre pressure monitoring system (TPMS) aims to monitor air pressure on various automotive systems. The most common TPMS sensors mainly use sub-GHz radio standards to transfer information to the vehicle’s computer. There are two different types: direct (dTPMS) and indirect (iTPMS). The use of bluetooth low energy (BLE) connectivity makes it possible offering a high performance. All information will be displayed in real-time by simple user interface with low power consumption. With low power consumption, applications can run on a small battery for many years. As result, it’s actually extremely positive when talking about M2M communication and automotive systems.

TPMS helps to avoid the tyre wear and improves road safety.  Due to the advantages of a longer battery life and connectivity, DA14585 is suitable for IoT applications in various industries. The figure 1 show a typical block diagram for a TPMS system.

block diagram of TMPS general system
Figure 1: block diagram of a TPMS. The block of transmission (transmit data) can implement the bluetooth low energy protocol.

Bluetooth low energy for automotive industry

Connectivity, Intelligence and energy saving are the main features for the new generation of IoT devices. Luckily, SmartBond can achieve all these features. Especially relevant is one of the series, DA14585 SoC. It offers all benefits, such as, full support of all bluetooth standards, including version 5. Moreover, it is suitable  for many applications, as remote controls, proximity tags, headlights, connected medical devices, smart home and smart automotive (Figure 2). The figure 2 shown the block diagram of DA14585, where is visualized the ARM M0 core and other peripherals.

block diagramm of DA14585 for bluetooth low energy applications
Figure 2: block diagramm of DA14585

With 96 kB of RAM and retention capability, DA14585 offers a wider memory than its predecessor in order to fully utilize standard features. Moreover, it also includes an integrated microphone interface for low-cost voice support. DA1485 supports a wide range of power supply voltages from 0.9 to 3.6 V. This range offers a wider choice of energy sources with a great design performance.

As a result, DA14585 represents the ideal solution to add bluetooth low energy technology to various applications. It supports Data Packet Length Extension, Link Layer Privacy v1.2, Secure Connections, Bluetooth Low Power Mesh and Efficient Connectable Advertising. Dialog Semiconductor has started contacting with the automotive industry for the construction of first TPMS devices with BLE. The goal is to manage the entire measurement process with the addition of sensors for measuring temperature and pressure. All powered by a simple battery.

The initial adoption of BLE technology for TPMS is a great opportunity for the automotive market and for new TPMS devices. As a result, the advent of BLE connectivity in automotive systems will open many connectivity scenarios for the smart automotive market.

Ultralow Power Transistors Function for Years Without Batteries

Researchers at Cambridge University have just achieved a spectacular breakthrough in electronics design. They have developed new ultralow power transistors that could function for months or even years without a battery. These transistors look for energy from the environment around, thus reducing the amount of power used.

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Dr Sungsik Lee, one of the researchers at the Department of Engineering says, “if we were to draw energy from a typical AA battery based on this design, it would last for a billion years.” The new design could be produced in low temperatures and they are versatile enough to be printed on materials like glass, paper, and plastic.

Basically, transistors are semiconductor devices that function like a faucet. Turn a transistor on and the electricity flows,  turn it off and the flow stops. When a transistor is off however, some electric current could still flow through, just like a leaky faucet. This current, which is called a near-off-state, was exploited by the engineers to power the new transistors.

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schematicThe researchers developed a thin-film transistor (TFT) from In-Ga-Zn-O (indium-gallium-zinc-oxide) thin films. To make the material less conductive, the films were fabricated to avoid oxygen vacancies. Eventually, they achieved a new design that operates in near the OFF state at low supply voltages (<1 volt) and ultralow power (<1 nanowatt).

The transistor’s design also utilizes a ‘non-desirable’ characteristic, namely the ‘Schottky barrier’ to create smaller transistors. Transistors today cannot be manufactured into smaller sizes since the smaller a transistor gets, the more its electrodes influence each other, causing a non-functioning transistor.The use of the Schottky barrier in the new design creates seal between the electrodes that make them work independently from each other.

“We’re challenging conventional perception of how a transistor should be,” said Professor Arokia Nathan of Cambridge’s Department of Engineering, the paper’s co-author. “We’ve found that these Schottky barriers, which most engineers try to avoid, actually have the ideal characteristics for the type of ultralow power applications we’re looking at, such as wearable or implantable electronics for health monitoring.”

According to Arokia Nathan of Cambridge’s Department of Engineering, the second author of the paper, this new design can see use in various sensor interfaces and wearable devices that require only a low amount of power to run. Professor Gehan Amaratunga, Head of the Electronics, Power and Energy Conversion Group at Cambridge’s Engineering Department sees its use in more autonomous electronics that can harness energy from their environments similar to a bacteria.

As electronic devices become more compact and powerful, conventional methods for manufacturing electrical components simply won’t do. This unconventional way will not only consume minimum power but it also will open up new avenues for system design for the Internet of Things and ultralow power applications.

This research was introduced as a research paper in Science magazine on October 2016. More details are available here  “Subthreshold Schottky-barrier thin-film transistors with ultralow power and high intrinsic gain”.