Elsevier

HardwareX

Volume 10, October 2021, e00213
HardwareX

Hypnos board: A low-cost all-in-one solution for environment sensor power management, data storage, and task scheduling

https://doi.org/10.1016/j.ohx.2021.e00213Get rights and content
Under a Creative Commons license
open access

Abstract

Open source in-situ environmental sensor hardware continues to expand across the globe for a variety of applications. Sensor-management systems typically perform three fundamental tasks: sample sensors at a specified time or period, save data onto retrievable media, and switch power to components on and off in between sample cycles to conserve battery energy and increase field operation time. These tasks are commonly accomplished through integrating separate off-the-shelf components into the desired system such as: power relays, SD card hardware, Real-Time Clocks (RTCs), and coin cell batteries. To enable faster prototyping, the Openly Published Environmental Sensing Lab abstracted all of these requirements into a single printed circuit board (PCB), Hypnos, that can be included in any project to achieve these commonly-required capabilities: powering on and off connected sensors on a schedule and logging collected data to the removable SD card. The hardware is laid out in a “Feather” form factor, a popular configuration in the open-source hardware community, to easily mate with other industry standard products. The onboard RTC acts as an alarm clock that wakes a user-attached microprocessor from low-power sleep modes in between sample cycles. By integrating all these components into a single PCB, we save cost while significantly reducing physical system size. The design as well as a suite of code functions that enable the user to configure all the Hypnos board features are detailed.

Keywords

Open source hardware
Environmental sensing
Low-power state
Data logging
Real-time clock
Relay

Cited by (0)

Bao Nguyen: Senior student in electrical engineering at OSU. He has been associated with the lab for most of his time at OSU. Bao enjoys his work by creating environmental sensing systems that collect data in remote locations.

Bryson Goto: An undergraduate student at Oregon State University (OSU) majoring in electrical and computer engineering and minoring in computer science. He is associated with the Openly Published Environmental Sensing (OPEnS) lab on OSU's campus and is associated with other environmental sensing projects through the lab.

John S Selker: Principle investigator for the OPEnS lab, OSU distinguished professor of Biological and Ecological Engineering, and co-Director of both CTEMPs and TAHMO.org. His areas of expertise include soil hydrology, environmental monitoring, mechanical, analog and digital electronic design. Dr. Selker has been a professor in the department of Biological and Ecological Engineering at Oregon State University for 26 years focused on Water Resources Engineering, publishing more than 175 peer-reviewed articles.

Chet Udell: Director of the OPEnS Lab and OSU assistant professor of Biological and Ecological Engineering. He received his PhD from the University of Florida in Music Composition and Electrical Engineering. He is inventor of U.S. and international patents on wireless sensor technology and data protocols and CEO of a technology startup company.