Riki&Dolphin: real time data transmission from the bottom of a cave to a website

Authors

• Luca Tringali, G.S. Talpe del Carso - J.K. Kraski Krti, ItalyFollow
• Giacomo Canciani Dr., G.S. Talpe del Carso - J.K. Kraski Krti, ItalyFollow
• Tecla Tripari, G.S. Talpe del Carso - J.K. Kraski Krti, Italy
• Alexander Debenjak, G.S. Talpe del Carso - J.K. Kraski Krti, Italy
• Caterina Bearzotti, G.S. Talpe del Carso - J.K. Kraski Krti, Italy

Highlights

• Dolphin sensors can be placed hundreds of meters deep in a cave
• Riki board can be placed outdoor, powering Dolphin with a 12 V battery for months 
• Main maintenance can be performed only on Riki and Dragino (outside the cave) 
• Data transmission through LoRaWAN, optional datalogging on a SD card placed outdoor 
• Modular customizable design, with support for analog, digital, I2C, serial sensors

Abstract

Coming from over 10 years of experience in cave monitoring in northeast Italy, Gruppo Speleologico Talpe del Carso, has designed Riki and Dolphin: customizable, low cost, and easy to assemble tools for getting real time data transmission from the bottom of a cave, even underwater, to a webserver. Their use has been tested to monitor air temperature inside the Abisso Bonetti Cave (Classical Karst, Italy), proving for the first time that a cave in Gorizian Karst can systematically be colder than the outdoor temperature even in winter, recording an internal temperature even lower than 0°C. The Dolphin device can be installed hundreds of meters deep inside a cave, transmitting data with standard Modbus protocol over an Ethernet cable to Riki, the external ground station, which also supplies power to the entire system with a battery that lasts many months. Riki then sends data through the LoRaWAN network (with a Dragino transmitter) straight to a webserver for data collection and visualization in real time (using Grafana). This allows cavers to enter the cave once and then get data every few minutes ideally forever. The Riki-Dolphin-Dragino-Grafana is a fully integrated solution, where each step is documented and released as Free Open-Source hardware and software.

DOI

https://doi.org/10.5038/1827-806X.ijs2603

Creative Commons License

This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License.

Recommended Citation

Tringali, L., Canciani, G., Bearzotti, C., Debenjak, A., Tripari, T., 2026. Riki&Dolphin: Real time data transmission from the bottom of a cave to a website. International Journal of Speleology, 52(2), ijs2603. https://doi.org/10.5038/1827-806X.ijs2603