myRIO: Replacing the Arduino for Control Applications

Abstract

National Instrument’s myRIO is a unique microcontroller that combines the flexibility of an ARM processor with the speed of a Field Programmable Gate Array (FPGA). The all-in-one package includes both analog and digital interfaces, with bipolar analog I/O, making it an ideal device for high-speed control. However, the existing tools, supplied by National Instruments, are inadequate for developing control applications. This report details an approach used to implement the control system directly onto the FPGA, allowing for high-speed control, while sending diagnostic information back through the processor to gather measurements from the controlled system. The test bed for the myRIO was Quanser Consulting’s Magnetic Levitation and Ball and Beam experiments. These experiments provided interesting control problems that required two dependent control loops. The controller was implemented both at the processor and FPGA level. For control applications where the time step is on the order of 1ms, implementing both loops on the processor produced adequate results. Moving the controller to the FPGA did not improve the controller at this timescale. Finally, this report concludes with a section detailing how one could include a myRIO into future projects. It includes diagrams and suggested structures for implementing controllers on the FPGA with minimum hassle. It also looks at the challenges that come with working with the myRIO system and what limitations exist with the device.