Ricki Septiando Sinaga, Beni Satria, and Hamdani Hamdani. “IoT Heart Beat Monitoring Based on Nodemcu ESP32”. INFOKUM 13, no. 05 (August 20, 2025): 1770-1783. Accessed September 13, 2025. http://seaninstitute.org/infor/index.php/infokum/article/view/3006.