Zoltan Kiss - Export Director - Endrich Bauelemente Vertriebs GmbH
Indoor Lighting-Powered Smart Sensors Forming an IoT Network
12 February 2025
Summary :
This year we continue presenting the intelligent IoT devices, equipment, and advanced technologies developed by Endrich and its collaborative partners. In this issue, we report on a significant innovation: we have developed and are preparing to showcase at EmbeddedWorld 2025 in Nuremberg a smart sensor family concept that stands out from competitors not only through its ultra-thin design and compact dimensions, but also through the multitude of cutting-edge technological solutions it incorporates. Since Endrich's development engineers firmly believe in the power of collaboration, we have conceived a device family whose realization is based on a truly pan-European project with the assistance of international partners. The newly developed E-zeroBatteryZone® wireless smart sensors integrate organically into the E-IoT ecosystem, working excellently alongside battery-powered counterparts and conventional E-IoT internet gateways, achieving this solely through energy harvesting without batteries. Endrich's innovation is empowered by several key partners: Denmark's NeoCortec company providing low-power radio modules (present from the first design concept), Sweden's Ligna Energy AB contributing specialized ultra-thin environmentally-friendly supercapacitors, and France's Dracula Technologies supplying special photovoltaic cells capable of harvesting light energy even under low indoor illumination conditions, making the system both powerful and sustainable.
Low-Power Wireless IoT Sensor Networks – Supported by NeoCortec's Neo.Mesh Solution
When deploying a relatively large number of smart sensors in a concentrated area with data routing to cloud services through a single point, we typically employ a low-power ad-hoc local sensor network solution, such as the NeoCortec Neo.Mesh wireless radio protocol. Numerous intelligent sensors can connect to a local network with ultra-low energy consumption, where a single internet-connected data concentrator/gateway ensures data delivery to the cloud database via mobile networks using protocols like LTE-M or NB-IoT cellular standards. Our engineering team has developed a modular sensor network infrastructure—previously detailed in this magazine—offering multi-point wireless communication through local mesh networking, while providing single-point internet access to the cloud via LPLAN-LPWAN gateways. Through the complete E-IoT ecosystem consisting of intelligent sensor networks, cloud databases, and visualization/data processing systems, our company can provide excellent solutions for transforming traditional devices into connected "SMART" devices, supporting applications such as predictive maintenance.
Neo.Mesh, our chosen Wireless Mesh Networking Protocol, represents a paradigm shift compared to traditional network architectures. Unlike conventional solutions that use a central network manager to control inter-node communication, this protocol employs autonomous intelligent nodes. Individual nodes function as independent entities, facilitating direct inter-node communication without central authorization. The result is a unified network that operates seamlessly, regardless of its size or complexity. As more and more nodes join the network smoothly, they connect ad-hoc to existing nodes, forming vast interconnected communication meshes. This adaptability and scalability are particularly valuable as E-IoT platform extensions when deployed in areas requiring coverage by hundreds or thousands of sensors.
One of the protocol's most impressive features is its patented routing mechanism, ensuring seamless data flow across the network even when RF path obstacles exist or nodes within the network are mobile. Traditional networks often struggle with performance issues when nodes are blocked or dynamically change position. However, the Neo.Mesh Networking Protocol eliminates such concerns, guaranteeing reliable data transmission at all times. Practically, this means network performance remains unaffected by environmental factors or dynamic changes within the network. Whether nodes are added, removed, or relocated, the network remains robust and fully operational, ensuring uninterrupted connectivity for all devices and users. It's remarkable how the protocol handles real-world network vulnerabilities—adding an additional node with proper network credentials seamlessly integrates into the existing network, supporting its coverage and enhancing performance.
At the core of Neo.Mesh technology lies a robust protocol suite with integrated security and reliability features. A key element of this security package is AES128 encryption for wireless communication between nodes. Through this encryption implementation, payload data and network communication remain impenetrable and unobservable to unauthorized and unreliable entities.
The E-IoT with Neo.Mesh local sensor network extension operates on sub-gigahertz frequencies to eliminate the issues faced by competing protocols in harsh industrial environments. Comparing sub-GHz networks to WiFi and Bluetooth using identical antennas and transmission power, it becomes evident that sub-GHz networks provide greater range. The extended range results from lower radio frequency waves being less readily absorbed by physical materials compared to the 2.4 GHz signals used by WiFi and Bluetooth.
These capabilities of the Neo.Mesh protocol provide ideal solutions for intelligent sensors deployed in large-scale industrial complexes such as factories, buildings, properties, and retail establishments.
Ultra-Low Power Architecture
The system is optimized for long-term battery operation with extremely low energy consumption, allowing batteries to last for multiple years. The Neo.Mesh network follows a time-synchronized protocol where each node spends most of its time in sleep mode. This architectural approach provides highly predictable energy consumption patterns for every node in the network. Consequently, all nodes consume nearly identical amounts of energy, enabling every network node to operate efficiently for many years.
While nodes experience higher power demand during the initial tens of seconds after activation, once synchronized to the network, average consumption drops to tens of µA magnitude.
Such solutions are fundamentally designed for battery-powered, long-term, multi-year operation, providing satisfactory solutions for sustainability and operational perspectives in most industrial applications. However, the question arises: could we design sensor nodes capable of operating indefinitely by eliminating battery replacement and associated operational costs while utilizing available environmental energy? Naturally, this requires optimizing sensor quantities and eliminating all other consumers—essentially requiring serious energy auditing and reduction.
Furthermore, in industrial environments, we can primarily rely on energy harvested from indoor lighting. We must handle its collection, temporary storage, and rapid delivery to circuits (primarily communication modules) when needed, all while maintaining the smallest possible environmental footprint.
Energy Harvesting System Architecture
For E-zeroBatteryZone® wireless smart sensors integrating into the E-IoT system, we wanted to use photovoltaic cells capable of generating energy even under low indoor illumination conditions. Energy harvesting is managed by a commercially available integrated circuit, while innovative energy storage relies on specialized supercapacitors whose geometric dimensions enable ultra-thin smart sensor designs using environmentally-friendly materials. The system block diagram is detailed in Figure 5.
Node architecture remains very similar across various low-power analog and digital sensors, consisting of: the NeoCortec communication module, sensors connected to the internal ARM-Cortex M0+ microcontroller's ADC pins or I2C channels, and the energy generation unit. The latter's main components include photovoltaic cells operating even under low indoor illumination, the energy harvesting IC, and specialized supercapacitor cells.
Light energy utilization efficiency in the applied photovoltaic cells is such that at 200 lux, >20 µA maximum charging current becomes available. Since the employed supercapacitors feature 2.7 V terminal voltage, we connected two such devices in series, enabling rapid energy discharge when communication devices activate.
Ligna Supercapacitors
A supercapacitor, also known as an ultracapacitor or Electric Double-Layer Capacitor (EDLC), is an energy storage device bridging traditional capacitors and batteries. Unlike batteries that store energy chemically, supercapacitors store it electrostatically, enabling rapid charging—ideal for applications requiring quick energy replenishment. However, their energy density is typically lower than batteries, limiting their use for long-term energy storage.
Ligna's supercapacitors are developed to meet growing demand for sustainable energy storage in wireless electronics. They offer the same advantages as traditional supercapacitors but with improved safety and reduced environmental footprint in compact form. The S-Power series is specifically designed to perfectly complement energy harvesters, providing environmentally-friendly supercapacitors for wireless electronics. Thanks to their excellent cyclic and performance capabilities, they are well-suited for applications requiring repeated rapid discharge and charging cycles.
Key Features:
- EDLC/supercapacitor technology
- Non-toxic, environmentally friendly
- Compact and thin profile
- Low leakage current
- Mountable on curved surfaces
Ligna supercapacitors maintain their rated capacity represented at 20°C relatively well across the -20…60°C operating temperature range, with only approximately 10% loss even at negative temperatures. The device features 1.2 F capacitance and 2.7 V terminal voltage, distinguished by impressively small mechanical dimensions (0.6 g weight, <0.5 mm thickness) alongside remarkable flexibility. They provide ideal energy storage for our E-zeroBatteryZone® devices.
Dracula Indoor Photovoltaic Cells
Dracula Technologies utilizes ambient lighting for energy generation through specialized, highly efficient organic materials capable of absorbing both natural and artificial light. Under low-light conditions, their OPV devices achieve high energy conversion efficiency—hence the fitting company name: like Count Dracula as an excellent vampire, the solar cell brand named after him performs effectively even under poor dawn-light conditions.
Beyond the Neo.Mesh-based device, the E-zeroBatteryZone® device family will expand in coming weeks with a new member: the LoRaMesh-based sensor module, implementing the Neo.Mesh protocol's LoRa modulation communication variant. We at Endrich are pleased to complement the E-IoT sensor family with such widely applicable, large-scale, local wireless networking solutions using energy-harvesting, battery-free technology. We will report on this device soon, and meanwhile warmly welcome dear readers to visit our stand at the Nuremberg EmbeddedWorld25 exhibition, where we will have complimentary copies of our book about the Endrich "E-IoT" concept, published at the end of last year.
References
This article has been published on the following locations:
| # | Media | Link |
|---|---|---|
| 1 | Magyar Elektronika 2025/1-2 | Beltéri világítás energiájával működő okosszenzorok alkotta IoT hálózat |
| 2 | Magyar Elektronika online | Beltéri világítás energiájával működő okosszenzorok alkotta IoT hálózat |
| 3 | Localized versions | Hungarian |