Wheelchair Navigation Aid Technical Content Review By Rob Riel

Overview Planned Workflow Top Level System Design Hardware Design Software Design Mechanical Design

Planned Workflow Design hardware devboard, use for testing, work out any gremlins Re-spin devboard once for connectors for final product Develop Software after dev board obtained Software Design Hardware Design Final Re-spin Debug Hardware

Top Level System Design System processes data from range finding sensors User is alerted visually and via sound of object encroachment. Product contains LCD screen which displays useful information Product also lights path of wheelchair with high power LED lighting

Top Level Design cont.

Hardware Design Hardware incorporates proven design practices such as: UART-> FTDI -> USB Total board breakout connectors for access to all pins. (great for debugging and development) Stable 8Mhz operation Over engineered power traces to prevent burnouts Onboard Temp monitoring

Hardware Design cont.

Hardware Layout

Rendered Product Electronics

Software Design Software incorporates maximum efficiency by using: ISRs whenever possible Lightweight LCD drivers designed in house DSP instructions which take 1 clk vs normal 4 clks. Because drivers are designed in house complete control is maintained over data flow, decreasing time to market due to debugging

Structure Definitions Overall Code Diagram Variable And Structure Definitions System And Peripheral Setup Run Time Routines and Data Processing

Variable and Structures Define Constants Define Sensor Struct Define Macros For Screen Define Screen Struct Define Loop Vars Define UART Struct

System and Peripheral Setup Setup Oscillator Setup ADC Regs Setup Watchdog Setup Interrupts Setup Pin State (TRIS) Setup UART Init Regs Set Initial Pin Output Initialize Screen

Run Time Routines & Data Processing Fetch & Store Sensor Data ISR For Change Mode Compare Sensor Data to Thresholds Update State Machine, Store to Screen Structure Calculate Bat Remaining ISR For Sending Data Via UART Update Screen

Mechanical Design Control Box

Mech Design LCD Box