1. PCB Layout Design

2. PCB Layout

3. Special Layout Considerations 4 in

4. Microcontroller Layout Considerations  Headers Programming header Debugging USART header  Routing considerations Micro must connect radially to all components Limit the use of vias  External oscillator Precaution; internal 8 MHz oscillator seems sufficient

5. Power Supply Layout Considerations  Multiple voltages 7.4 V battery for motor 5.0 V regulated for micro and other components  Power lines Direct routing of power to each subsystem Difficult due to board size/shape  Passive components Decoupling and bulk capacitors

6. Things to Do  Add headers for unused port pins  Connect headers: Analog sensor header Programming header I2C header for compass  Increase thickness of power traces  Add idiot-proof connectors  Reverse voltage protection diode