Self-Sustaining Solar-Powered Remote Climate Monitoring Node

Project Overview

This project involves the development of an advanced environmental monitoring device built around the Nordic Semiconductor nRF9151 chipset. The goal is to create a self-sustaining system capable of gathering environmental data in remote and off-grid locations, where traditional network infrastructure like WiFi may be unavailable or unreliable. The device will utilize various environmental sensors to collect data on parameters such as carbon dioxide (CO2) levels, atmospheric pressure and other key environmental metrics. Sensor connectivity is facilitated through QWIIC connectors, providing flexibility for sensor integration. While no sensors are currently integrated, the design includes four QWIIC connectors—two essential and two additional for future expansion.

The device is equipped with LTE connectivity and SIM connector, enabling seamless data transmission over cellular networks. This capability ensures that environmental data collected from the sensors can be sent to a central base station, even in areas with limited or no WiFi connectivity. This makes the system ideal for environmental research applications in remote regions.

One of the standout features of this device is its ability to determine its geographical location using a Global Navigation Satellite System (GNSS) sensor. The GNSS sensor provides precise location data, ensuring that the environmental readings can be geo-tagged, which is crucial for applications that require spatial awareness.

The device is designed to be self-sustaining, meaning it can operate autonomously without the need for external power sources or frequent maintenance. It is powered by a dual-source system that includes both a Type-C input for powering from a DC power adapter and a solar panel. The solar panel is used to charge the device's onboard battery, ensuring that it remains operational even in areas where there is no access to conventional power sources. The solar energy harvesting system is integrated with an efficient power management solution using the Nordic nPM1300, which handles battery charging, monitoring, and overall power distribution. The nPM1300 ensures optimal battery charging from both the solar panel and Type-C input, maintaining uninterrupted operation even when one power source is unavailable. Dual power input functionality is achieved through external circuitry, providing seamless switching and enhanced system reliability. While the device is equipped with a Type-C input for occasional charging, it is primarily designed to operate autonomously, drawing power from the integrated solar panel. This ensures the system's self-sustaining capability, allowing it to function independently without the need for continuous external power sources

To optimize power consumption, the system utilizes a hibernate power mode, allowing the device to enter an ultra-low-power state during periods of inactivity. This is especially useful in scenarios where sensor data transmission is periodic, reducing overall energy consumption and extending battery life. Additionally, solar panel health monitoring is implemented using a shunt resistor placed between two analog pins, enabling continuous tracking of power generation efficiency and system performance..

Data collection from the environmental sensors is performed at regular intervals, with all sensor data being transmitted over the LTE network to a central base station for further analysis. In addition to the environmental data, the system also transmits health metrics, such as solar panel health, battery status, and charge levels, to the base. This allows for real-time monitoring of the system’s performance, as well as early detection of any potential issues with the power system or sensors.

The self-sustaining nature of the device, combined with its remote connectivity and real-time data transmission, makes it an ideal solution for applications in areas where traditional power infrastructure is absent or unreliable. It enables continuous, real-time environmental monitoring in even the most remote or harsh environments.

Key Advantages Over Existing Solutions

While there are various environmental monitoring systems available today, the self-sustaining and remote capabilities of this device set it apart from traditional solutions in several key ways:

• Self-Sustaining Power System: Most existing environmental monitoring devices rely on fixed power sources, such as AC/DC adapters, requiring regular maintenance or being dependent on nearby electrical infrastructure. This system, however, utilizes a dual power input system: Type-C for charging via a DC adapter and a solar panel to continuously charge the battery, enabling the device to operate autonomously in off-grid locations. The inclusion of a solar panel significantly reduces maintenance needs, as it eliminates the need for frequent battery replacements or manual charging, which is often a limitation in existing solutions.
• Use of LTE Connectivity for Data Transmission: Traditional environmental sensors often rely on WiFi or Bluetooth for data transmission, which limits their usability in remote areas where WiFi infrastructure may be unavailable. This system stands out by incorporating an external LTE module and SIM connector, enabling the device to send real-time data over cellular networks. This feature ensures that data can be transmitted even in areas with little to no WiFi coverage, making it highly adaptable for remote or harsh environments.
• Remote Monitoring of Power Health: Unlike many existing devices that simply collect and transmit environmental data, this system also includes real-time monitoring of its power sources. The nPM1300 power management system not only controls battery charging but also tracks the health the battery. Data on battery status, other parameters monitoring and overall system power status is transmitted to the base station, allowing for proactive maintenance and ensuring the device remains operational even in cases of power-related issues. Similarly the data on solar panel power health are also transmitted ensuring the remote monitoring of the device health.
• Geographical Location Awareness with GNSS: Many environmental monitoring devices fail to incorporate location tracking, which can be a crucial feature for applications that require precise geo-tagging of the collected data. This system addresses this by integrating a GNSS sensor, which allows the device to accurately determine its geographical location. This feature is essential for tracking environmental conditions in various locations, particularly for applications like agricultural monitoring, wildlife tracking, and research in diverse environments.
• Autonomous and Continuous Operation: Most current solutions require periodic human intervention for charging, maintenance, or data retrieval. This system, however, is designed for continuous, autonomous operation. It collects environmental data at regular intervals and transmits it over LTE without requiring manual intervention. The combination of solar charging, LTE data transmission, and power management ensures that the device remains operational in a completely autonomous manner, reducing operational costs and human oversight.
• Long-Term Deployment in Harsh Environments: Existing solutions often struggle with long-term deployment in remote or harsh conditions due to limited power sources and the need for frequent servicing. The integration of solar energy and the robust power management features of this system enable long-term deployment with minimal maintenance. It is particularly well-suited for environmental monitoring in regions with limited access to electricity or frequent power outages.
• Scalability and Flexibility: The nRF9151-based self-sustaining environmental sensor device is designed for flexible and scalable deployment, adapting to diverse network requirements. With support for NB-IoT, LTE, Bluetooth (BLE), Zigbee, and Mesh, and future NTN integration, the system can be deployed in various environments with optimal connectivity choices.In scenarios where long-range communication is essential, LTE or NB-IoT ensures seamless data transmission. However, for short-range applications, BLE can be utilized, significantly reducing power consumption and network dependency. When deploying multiple devices within a localized area, Mesh networking can interconnect sensors, allowing efficient data relaying without relying on direct LTE connections. This approach optimizes power usage, reduces costs, and enhances network reliability by distributing communication loads effectively.With this adaptive connectivity strategy, the system remains highly scalable, making it suitable for small-scale environmental monitoring as well as large-scale sensor deployments in remote or urban locations.The ability to add more environmental sensors (through additional QWIIC connectors) and manage power effectively through the solar panel and Type-C input ensures that this device can be adapted to a variety of use cases, from small-scale monitoring in isolated areas to large-scale environmental networks.