Project Proposal

By Brycen Westgarth and David Mleczko


Overview:

We are going to use the STM32L476 Discovery board to create a 2D image plotter that can print digital binary image data into a physical ink drawing consisting of marker dots. The main mechanical portion of our device will be a marker mounted on a 2 axis rail system driven by stepper motors that will allow us to access each portion of our drawing medium in Cartesian coordinates. A black pixel in the image will correspond with a marker dot in the corresponding location on the paper. The marker will be mounted on a solenoid on the main movable platform which will allow us to move the marker down onto the paper. The binary image data will be limited by a max resolution of 480x640 due to machine size constraints. Because of the high current draw of the solenoid we will need to monitor its temperature throughout the print via a I2C compatible temperature sensor and pause the print whenever the solenoid gets too hot. The actions of the printer will be controlled through a UART connection to a terminal on a computer.


Peripherals:

  • 3 stepper motors

  • Stepper motor driver

  • Solenoid

  • Relay

  • Push Button

  • Temperature Sensor


Software Design:

Image Processing

We will write software for image processing that will convert our image to black and white data that can be used to control the solenoid. Data will be implicitly indexed with a 1D array in relation to the position of the marker on the paper.


Communication:

We will write code that will allow us to communicate with our serial interface modules(Temperature Sensor and UART terminal) which will be the sources of our image data. The Temperature Sensor communication will follow the I2C protocol.


Plotting:

We will write code that will allow us to drive our stepper motors and control the position of our 2D rail system holding the marker. Stepper motors will be driven to move the marker in calibrated distances corresponding to the pixels of our images in both the x and y directions.


High level control software:

We will need software that dictates proper delay and procedure when controlling the different mechanical and software components of our total machine as well as any user interface we decide to add.


Responsibilities:

Brycen - Solenoid control, Image conversion software, Image Read

David - Stepper Motor control software, Overhead control software

Both - Mechanical Construction, Calibration, Misc Testing software


Goals:

  • Accurate X-Y coordinate plotting

  • Non-distorted image

  • Mechanical reliability

  • 480x640 max image resolution

  • Reasonable drawing speed