Digi-Brush Software Narrative Presenter: Caleb Ayew-ew Team Members: Josh Long Katie Schremser

Software Design Considerations Two Major Devices to be Programmed – Freescale MC9S12DP512MPVE Handles Color Changing, Touch Screen, and Force Resistor ATD conversions “Debounces” Save and Clear buttons Generates I2C packets for Brush’s LED Driver SPI communication with FPGA – Cyclone II FPGA Process SPI from Micro – Generates Analog VGA signal for VDAC – Saves image to SD card via SPI

Flow Main() Start Initialize Peripherals and Registers getTouchScreen() updateDisplay() getColorPots() updateLEDDriver() save() Clear() decodeSPI() Function? Save() Clear() Update() Micro Process FPGA Comm. FPGA Process

Micro-Controller Narrative To get the touch screen information 5 ATD conversions are collected for the X coordinate and averaged, then the STDx is taken. If STDx 10 it will continue to get Y then repeats the process. After a touch is recognized a packet is formed and sent via SPI to the Cyclone II device. This packet contains the current color and coordinates just calculated. Analog inputs for the Color pots will continuously be converted and polled. When a pot is selected, the microcontroller will recognize it by determining the change in ATD value. The current color will then average with the recently pressed color to simulate mixing. The current color will be sent to the LED driver when it changes via IIC protocols. Then two GPIO pins are used as interrupts to save or clear the image. These are “debounced” in software by comparing previous values with current ones. If pressed another packet will be formed and sent to the FPGA. This packet will simply state that a save or clear request has occurred.

FPGA Narrative Once a packet is received from the Micro it decodes it. – Save will check to see if an SD card is there if so it will fetch all the information stored in the external RAM, convert to viable format(unsure which yet) then write it onto the SD card. If no SD is present, it will do nothing. – Clear will send 3FFh to all RGB pins to create a new white screen. – Update Display operates using double buffering. It will write the coords. and colors from the Micro into external RAM then when finished transfer that information from RAM into the VDAC.

Hierarchy Main() Main getTouchPanelgetColorPots changeColor updateLEDDriver frATDupdateDisplayisrVrtiSave/Clear

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