This paper details the mechanical and electronic design of a modular snake robot, the Little Red (LR). 3-D printing technology is applied to shorten the manufacturing cycle. With power, sensing, communication and control electronic circuit integrated, each rotation module is independent and full-featured. Additionally, the control system based on Internet of Things (IoT) is more intelligent. The establishment of ZigBee wireless networking can realize reliable wireless data transmission at low power consumption. Experiments are conducted to show the effectiveness of the mechanical and electronic design and the reliability of the control system.