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.
Greetings inhabitants of the FPGA world! Today’s post is about a project that can be a huge part of a number of other different projects that use FPGA as their core. Be it a claw machine or a drone or a navigator robot, interfacing Joysticks with FPGA will be a fundamental part of many of your future work. This article will help you control any device on a two dimensional platform with the code for movement in the XY plane. Moving in 3D (flight in the case of drones) can be easily achieved by using two joysticks in place of one.
The Author has wrapped up her project in a set of 5 steps to keep things short and sweet. The hardware needed for this project is simply a FPGA board, a system with Xilinx Vivado installed, Digilent PmodJSTK and a USB A to B micro cable. A general idea regarding the project is given in Step 2. The Joystick uses the SPI interface to receive and transmit data from and to the FPGA board.
The code for this project has been readily supplied in step 3 as a zip file. The contents can be sorted into a number of modules which have been coded in Vivado 2015.4. So using a different version of the software will mean you need to copy paste the codes into a new project file in your system.
The code can then be converted to bit stream to programme the board. You can also programme 2 joysticks (for Drones or RC Cars) since only the top bank of the PMOD Header in the FPGA board (you may need to adapt this to your own board) has been used for 1 joystick.