Greetings FPGA innovators! Stepper motors can be an integral part of projects that have a dimension of mobility to them. Be it rovers, robots, drones or claw machines, controlling stepper motors with joysticks is an integral part and FPGAs accomplish speed control easily. Today’s post is about using a FPGA and a joystick to control stepper motors.
The Hardware required for the project is a FPGA board, 2 PmodSTEP drivers, 1 PmodJSTK, 2 Stepper motors, a USB A to B micro cable and 2 12 pin PMOD cables. Since the author is only focused on the control of the stepper motors, the hardware for this project is limited. However it can be expanded based upon the scale of your endeavour.
The code structure is given by the author in step 2. The author has configured the PmodJSTK interface to receive data and not send data to the LEDs on the board. The working principle is pretty simple, where the decoder works out the signals from the Joystick and sends it to the drivers in the form of electrical signals that make the motors turn left, right, stay still or maintain course. The FPGA acts as a simple interconnect between the drivers. The code has been given in a zip file by the author in step 3.
The coding language used is VHDL and the code is divided into modules. Step 4 has been dedicated to code generation and creation of the executable bit file that can be used on the FPGA. Step 5 illustrates the connections for the project.