{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,16]],"date-time":"2026-06-16T09:55:02Z","timestamp":1781603702948,"version":"3.54.5"},"reference-count":23,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2021,12,7]],"date-time":"2021-12-07T00:00:00Z","timestamp":1638835200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Ministry of Science and Technology of the Republic of China","award":["MOST 110-2622-B-212-003"],"award-info":[{"award-number":["MOST 110-2622-B-212-003"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Water temperature, pH, dissolved oxygen (DO), electrical conductivity (EC), and salinity levels are the critical cultivation factors for freshwater aquaculture. This paper proposes a novel wireless multi-sensor system by integrating the temperature, pH, DO, and EC sensors with an ESP 32 Wi-Fi module for monitoring the water quality of freshwater aquaculture, which acquires the sensing data and salinity information directly derived from the EC level. The information of water temperature, pH, DO, EC, and salinity levels was displayed in the ThingSpeak IoT platform and was visualized in a user-friendly manner by ThingView APP. Firstly, these sensors were integrated with an ESP32 Wi-Fi platform. The observations of sensors and the estimated salinity from the EC level were then transmitted by a Wi-Fi network to an on-site Wi-Fi access point (AP). The acquired information was further transmitted to the ThingSpeak IoT and displayed in the form of a web-based monitoring system which can be directly visualized by online browsing or the ThingView APP. Through the complete processes of pre-calibration, in situ measurement, and post-calibration, the results illustrate that the proposed wireless multi-sensor IoT system has sufficient accuracy, reliable confidence, and a good tolerance for monitoring the water quality of freshwater aquaculture.<\/jats:p>","DOI":"10.3390\/s21248179","type":"journal-article","created":{"date-parts":[[2021,12,7]],"date-time":"2021-12-07T20:23:21Z","timestamp":1638908601000},"page":"8179","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":71,"title":["An Integrated Wireless Multi-Sensor System for Monitoring the Water Quality of Aquaculture"],"prefix":"10.3390","volume":"21","author":[{"given":"Jen-Yung","family":"Lin","sequence":"first","affiliation":[{"name":"Department of Computer Science and Information Engineering, Da-Yeh University, Changhua 515006, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0177-633X","authenticated-orcid":false,"given":"Huan-Liang","family":"Tsai","sequence":"additional","affiliation":[{"name":"Department of Computer Science and Information Engineering, Da-Yeh University, Changhua 515006, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wei-Hong","family":"Lyu","sequence":"additional","affiliation":[{"name":"Department of Computer Science and Information Engineering, Da-Yeh University, Changhua 515006, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,12,7]]},"reference":[{"key":"ref_1","unstructured":"Food and Agriculture Organization of the United Nations (FAO) (2020). 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Available online: https:\/\/media.digikey.com\/pdf\/Data%20Sheets\/DFRobot%20PDFs\/SEN0161-V2_Web.pdf."},{"key":"ref_12","unstructured":"Environmental Protection Administration (EPA) United States (2021, July 07). Chesapeake Bay Total Maximum Daily Load for Nitrogen, Phosphorus and Sediment. 29 December 2010, pp. 3\u20139, 3\u201310, Available online: https:\/\/www.epa.gov\/sites\/default\/files\/2014-12\/documents\/cbay_final_tmdl_exec_sum_section_1_through_3_final_0.pdf."},{"key":"ref_13","unstructured":"DFRobot (2021, March 21). Analog Dissolved Oxygen Sensor\/Meter Kit for Arduino. Available online: https:\/\/media.digikey.com\/pdf\/Data%20Sheets\/DFRobot%20PDFs\/SEN0237-A_Web.pdf."},{"key":"ref_14","unstructured":"Fondriest Environmental, Inc (2021, July 07). \u201cMeasuring Dissolved Oxygen.\u201d Fundamentals of Environmental Measurements. 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A Fish Farmer\u2019s Guide to Understanding Water Quality. Available online: https:\/\/southcenters.osu.edu\/sites\/southc\/files\/site-library\/site-images\/FishFarmersGuideToWaterQuality.pdf."},{"key":"ref_19","unstructured":"Espressif Systems (2021, May 14). ESP32 Series Datasheet, Ver. 3.7. Available online: https:\/\/www.espressif.com\/sites\/default\/files\/documentation\/esp32_datasheet_en.pdf."},{"key":"ref_20","unstructured":"(2021, May 14). ThingSpeak. Available online: https:\/\/thingspeak.com\/channels\/1408273."},{"key":"ref_21","unstructured":"Honeywell (2021, May 14). Thin Film Platinum RTDs: HEL-700 Series. Available online: https:\/\/sensing.honeywell.com\/honeywell-sensing-hel-700-series-thin-film-platinum-rtd-productsheet-009080-1-en.pdf."},{"key":"ref_22","unstructured":"FOPTOD (2021, May 14). FOPTOD Optical Dissolved Oxygen. Available online: http:\/\/www.jetec.com.tw\/pdf\/6\/english\/FOPTOD_E_data.pdf."},{"key":"ref_23","unstructured":"Vernier (2021, May 14). Salinity Sensor. Available online: https:\/\/www.vernier.com\/files\/manuals\/sal-bta\/sal-bta.pdf."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/24\/8179\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:42:50Z","timestamp":1760168570000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/24\/8179"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,12,7]]},"references-count":23,"journal-issue":{"issue":"24","published-online":{"date-parts":[[2021,12]]}},"alternative-id":["s21248179"],"URL":"https:\/\/doi.org\/10.3390\/s21248179","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,12,7]]}}}