Wireless control system for angular positioning applications

In this paper is presented an angular positioning system based on stepper motors and remotely controlled using a wireless communication link. The wireless control system is intended to be used in a wide range of applications including the robotic arm positioning, automatic orientation of photovoltaic panels, video cameras or antennas. The proposed design is compose by two modules (transmission/reception) which can communicate wireless in 2.4 GHz frequency bandwidth using direct sequence spread spectrum transmission technique (DSSS) for achieving high immunity to noises and jamming. Both modules are implemented around two PIC 16F887 microcontrollers. The radio system is based on dedicated module XTR VF 2.4 LP which is connected to the microcontroller using serial peripheral interface bus (SPI). The system uses two stepper motors for obtaining two degree of freedom in angular positioning. The accuracy of the stepper motors is of 0.9 degrees. The user interface of the system consists in a display and a small size keyboard for introducing the positioning parameters. Compared with other implementations, the novelty of the proposed system consists in a reliable hardware design, based on performing communication modules and versatile microcontrollers running complex software application that allows accurate control, without operation errors.