RAINdot is a rainfall datalogger that utilizes the latest NB-IoT wireless transmission technology to measure the pulse count signal from the rain gauge. This datalogger features a sturdy, waterproof enclosure and a low power consumption design. It is powered by two 18650 lithium-ion batteries and offers long-term measurement and data upload to the dot cloud platform, with an additional 5-18 Vdc charging function. Furthermore, the built-in 32 GB Micro SD card is capable of storing over 1 million data entries. RAINdot is also compatible with various rain gauge devices, enhancing its versatility for different applications. RAINdot is suitable for rainfall monitoring in urban civil engineering projects, river and water conservancy projects, bridge engineering, and slope safety monitoring.