Development of Mobile Vehicles with Functions of Water Quality Sensing and Underwater Photography for Aquatic Farms

In this study, a Raspberry Pi 4, model B with a single-chip host, is used as the robot upper computer to issue control commands. ESP32-WROOM-32U and Arduino Nano are used as the lower computers. A mobile vehicle powered by four sets of pumping motors was built. In the software part, Raspbian system is used as Raspberry Pi OS, and the control program is written in Python and C language as well as connect Raspberry Pi with ESP32 and Arduino Nano for communication. A PWM control signal is outputted by Arduino Nano to switch the four groups of motors to complete the forward and reverse rotation and speed control functions of DC motors. Through a QMC5883L electronic compass module to calculate changes of three-axis magnetic field to compute an azimuth angle, and the distance between itself and the pool wall is measured by GP2Y0A02YK0F infrared distance sensor. Then an attenuation strength of iBeacon signal is combined to achieve the internal positioning in an aquatic pool for mobile vehicles on water.