PID Control of 6V DC Motor
Microcontrollers have become ubiquitous in the world of modern electronics. Typically designed to accomplish a dedicated function with an embedded system, microcontrollers are found in a wide variety of technologies. This repository presents the design and implementation of a basic traction control system using a Cortex-M4 microcontroller (MCU), a 32-bit Arm-based processor docked in a Nucleo-64 development board (STM32F446RETx). The motor utilized in this system was a fairly simplistic brushed DC motor (3777 "TT Motor"). The system is equipped with a Hitachi liquid-crystal display (LDC) operated in 4-bit mode, a transmissive photointerrupter to detect the rotational speed of a wheel (GP1A57HRJ00F photodiode pair), and a motor driver (L293X Quadruple Half-H).
C programming is used to accomplish speed control of a brushed DC motor using closed-loop control feedback based on proportional-integral-derivative (PID) control theory and pulse-width modulation (PWM). Utilizing the STM32’s nested vector interrupt controller (NVIC), low-latency exception and (external) interrupt handling was shown to be a feasible and tractable solution to processing mode switching.
While dynamic control was achieved in the context of “mode switching”, further improvements to the posited design could be made in terms of a more realistic implementation of cruise control; future work includes noise reduction, utilization of prioritized interrupts, and more realistic physical prototyping.
[1] Mazidi, Muhammad Ali, et. al., ARM Assembly Language Programming & Architecture. MicroDigitalEd, 2016.
[2] Mazidi, Muhammad Ali, et. al., STM32 ARM Programming for Embedded Systems Using C Language with STM32 Nucleo. MicroDigitalEd, 2016.
[3] RM0390 Reference Manual: STM32F446xx advanced Arm-based 32-bit MCUs, 6th ed. STMicroelectronics., Geneva, Switzerland, 2021.