How to implement a maintenance-free sensor node

How to implement a maintenance-free sensor node

As a key part of the IoT ecosystem, sensors are used to sense and collect data such as temperature, humidity, distance, and liquid level, and transmit them through connection protocols such as Ethernet, Wi-Fi, Bluetooth Low Energy (BLE), ZigBee, and Sigfox. And aggregate data, and then analyze these data through special software and take action, and finally realize applications such as system automation, predictive maintenance, intelligent agriculture, intelligent medical care, and analysis of massive data in the Internet of Things world. With the rapid growth of the Internet of Things, the demand for data storage, processing, and transmission is getting higher and higher, which will become a major issue for the sustainability of the project. Consider designing ultra-low-power embedded hardware platforms, self-powered energy harvesting, intelligent system-level power management, and other solutions to address the energy challenges faced by designers.

From low power consumption to battery-free

Battery-free sensor nodes reduce costs because no battery replacement or maintenance is required, and sensor life is longer. Adopting a battery-free IoT is also conducive to sustainable development, as it reduces dependence on restricted raw materials such as cobalt, and recycling budgets. Electromagnetic switches, solar cells, and vibration energy harvesters are reliable, proven battery-free technologies that are suitable for applications such as smart buildings, home lighting control, remote control, building automation for opening doors and windows, and elevator doors for maintenance applications Counters, fire extinguisher off-hook detection for safety applications, etc.

Low-power interconnection protocols are key to achieving battery-free, such as Bluetooth low energy and Zigbee® Green Power. Bluetooth Low Energy is ubiquitous today and is a widely distributed ecosystem. Both Bluetooth Low Energy and Zigbee? Green Power have ultra-low power consumption, supporting battery-free applications through energy harvesting. Devices that support Bluetooth Low Energy or Zigbee? Green Power can be added to the Mesh network to achieve safe and secure expansion in the extended range. Many-to-many communication.

The industry's lowest power Bluetooth 5 radio system single chip (SoC) RSL10 is extremely suitable for achieving a completely battery-free solution through energy harvesting. It consumes 7 mW in receive mode and only 62.5 nW in deep sleep mode, which is the highest in the industry. EEMBC? ULPMark? Score. RSL10 system-in-package (SIP) integrates RSL10 radios, antennas, and all passive components in a 6 x 8 x 1.46 mm miniature package, simplifying system design and minimizing bill of materials (BOM), making it easy to design and import into any smart wireless In connected applications, it has passed the certification systems of the United States, Europe, Japan and other countries.

Ultra-low-power embedded hardware platform: RSL10 sensor development kit

The RSL10 sensor development kit combines the industry's lowest power RSL10 SIP and Bosch Sensortec's cutting-edge sensor technology, including more than a dozen low-power sensors including ambient light, inertial and environmental sensors to achieve power-optimized sensors with long battery life Nodes are used in smart home, smart building, asset tracking, personal internet of things and other applications. The suite is highly integrated, compact, and includes a software development environment and a cloud-connectable mobile application (App) RSL10 Sense and Control, out of the box, to simplify and accelerate development. This app reads the many sensors supporting the kit and sends the sensor data to the cloud via MQTT. It can also subscribe to actuator data from the cloud via MQTT. For example, use the RSL10 sensor development kit to quickly build, test, and deploy applications such as industrial wearables or asset monitoring for worker safety. In worker safety application use cases, falls can be detected and alarms can be quickly issued to reduce the response time to emergencies. Hazardous conditions that are harmful to high temperatures can also be detected in advance, ultimately reducing the risk of injury, reducing operating costs, and increasing production efficiency.

Energy harvesting solution: RSL10 solar cell multi-sensor platform

The new cutting-edge sensor development platform RSL10 solar cell multi-sensor platform, completely powered by solar energy, is battery-free and maintenance-free, filling the gap in energy demand. This platform is based on the industry's lowest power RSL10 SIP, combined with Bosch Sensortec's ultra-low-power smart sensors for continuous temperature, pressure and humidity detection, and transmits data to the cloud gateway for cloud interconnection through Bluetooth low energy, for climate control, workers Security and mobile health applications.

RSL10 solar cell multi-sensor platform features include:

¡ñ Provide continuous monitoring technology without battery.

¡ñ Provides the industry's lowest power Bluetooth? Low power technology through RSL10 SIP.

¡ñ 55 nw in standby mode and 10 mW at Rx and Tx at 0 dbm.

¡ñ Support beacon and telemetry transmission.

¡ñ SEGGER J-Link with Arm ™ Cortex ™ debug connector (10-pin) adapter is fully reprogrammable.

¡ñ Ultra-low leakage current.

¡ñ Adaptive duty cycle (energy available for self-test is used for transmission).

¡ñ Double solar cell interface (through-hole wire welding or ZIF interface).

¡ñ Ultra-low-power smart sensor.

¡ñ Low-voltage, high-precision temperature sensor with wide temperature range (-40 to 125 ¡ã C) (NCT203).

¡ñ Combined with digital humidity, pressure and temperature sensors (BME280).

¡ñ Intelligent 3-axis ultra-low-power accelerometer (BMA400) with integrated wake-up and sleep functions.

¡ñ Pre-flash contains interleaved Beacon firmware.

¡ñ Eddystone TLM Beacon.

¡ñ Transfer storage capacitor voltage level, temperature, time after power-on, and advertising packets after power-on.

¡ñ Compatible with Bluetooth Low Energy (BLE) Scanner application (iOS? Or Android?).

¡ñ Beacon, a customized environmental service.

¡ñ Transmission temperature, humidity and pressure.

¡ñ Software library and examples are provided in B-IDK CMSIS-Pack.

¡ñ Support a variety of lighting conditions (artificial or solar lights, as low as 180 lux).

Energy harvesting solution: Bluetooth low energy switch

ON Semiconductor's Bluetooth low-power switches work entirely with harvested energy to enable truly self-powered IoT applications. Application examples include wall and lighting control, building automation, and asset tracking. This solution combines the industry's lowest power RSL10 SIP and ZF Friedrichshafen AG's high-performance energy harvesting switch. Each press and release of the button generates 350 ¦ÌJ of energy, which is equivalent to only 0 dBm per transmitted signal. Consumes 17 microjoules (¦ÌJ). This Bluetooth low energy switch does not require buck-boost, reduces BOM by 25%, and is compatible with ON Semiconductor ¡¯s IoT Development Kit (IDK) and Bluetooth IDK (B-IDK), including sensors, connections and actuator devices. Comprehensive lineup, easy to connect to standard BLE Scanner or mobile / lighting applications (iOS? Or Android?), Complete with BoM, circuit diagram, PCB layout and Gerber files, and free use of switch-side firmware.

Energy harvesting solution: Zigbee Green Power switch

Zigbee Green Power is based on the IEEE 802.15.4 specification and targets battery-free, self-powered equipment through energy harvesting. ON Semiconductor ¡¯s Zigbee Green Power energy harvesting switch solution includes an energy harvesting switch, a NCS36510-based Zigbee Green Power module, and a Zigbee3.0 GP protocol stack. Advantages include: battery-free and maintenance-free, cost advantages, and long-distance connection , Simple installation, compatible with commercial products, local Mesh. The NCS36510 is an ultra-low-power SoC radio frequency transceiver. Its receive power and transmit power are as low as 6.7 mW and 6.0 mW, respectively. Typical applications of this solution are lighting control, automatic door / window opening, etc.
RFID technology

Radio frequency identification (RFID) tags use the power provided by the antenna to power the chip and send a return signal in the form of data. This data may be a command to unlock the door, a unique ID, sensor detection data such as temperature. RFID reading range is 10 cm high frequency, passive ultra high frequency (UHF) is about 10 m (different due to reader power, antenna design, tag design, direction), active UHF is about 100 m. ON Semiconductor's smart passive wireless sensor is a battery-free RFID sensor that provides temperature monitoring, distance detection, water leakage detection and liquid level detection. It can read hundreds of tags at the same time, which has a cost advantage. Easy to collect operating data for analysis and action, rapid deployment, no maintenance required, suitable for challenging environments such as behind walls, moving objects, etc. The reader can be mounted on a fixed ceiling, door, table, shelf or mobile Hand-held devices, robots, and drones, use cases include occupancy detection in conference rooms by period, office temperature monitoring, air quality monitoring, asset management, warehouse leak detection, factory motor temperature / vibration monitoring, electrical switchgear monitoring, and more.

Intelligent system-level power management enables 10-year battery life

IoT nodes have two typical working modes: active mode and low power mode. In most use cases, the percentage of time the device is in active mode (called the duty cycle) is small, 99% of the time it is in idle or low-power mode, requiring only very low power from the battery. Therefore, making full use of the dual-mode characteristics of IoT nodes, using sleep duty cycle technology, minimizing the time of the active mode, and extending the time of the low-power mode as much as possible, can significantly reduce system power consumption and help extend battery usage life.

Low-dropout voltage regulator (LDO) with low quiescent current for low-duty-cycle IoT applications helps to achieve 10-year battery life. For example, ON Semiconductor's dual-mode 50 nA LDO NCP171 provides up to 80 mA in active mode and quiescent current as low as 50 nA in low-power mode. NCP171's innovative dual-mode structure has excellent noise and dynamic performance required for reliable RF transmission in active mode, and extremely low noise performance required for accurate sensing, while providing ultra-low Iq to low power mode Extend battery life. These two LDO modes can be selected by switching the dedicated ECO pin. The NCP171 also has a built-in voltage offset when switching to low-power modes to further reduce system power consumption, ranging from 50 mV to 200 mV. In addition, compared to traditional buck regulators, the total cost is reduced due to fewer devices and smaller footprint.

to sum up

Sensors in IoT applications have proliferated with the rapid development of the IoT, and solutions such as ultra-low-power embedded hardware platforms, self-powered energy harvesting, and intelligent system-level power management are needed to solve the energy challenges facing designers. ON Semiconductor provides intelligent system-level power management solutions to achieve 10 years of battery life. It also combines energy harvesting and ultra-low-power wireless interconnection technologies such as Bluetooth, Zigbee Green Power, and RFID-based solutions to make battery-free, Maintained sensor nodes are possible, in line with the trend of environmental protection and energy saving, and significantly reduce the total cost of ownership.