Open source hardware PDA with Linux preinstalled.

Motivation Edit

  • Educational applications (e-books, CS lessons, etc)
  • People need quick access to news, weather, Web, or digital books
  • People need peer-to-peer voice or data connectivity, especially in infrastructure-poor places

Design Goals Edit

  • Small, cheap
  • Long battery life
  • Peer to peer ad-hoc wireless TCP/IP networking
  • Free software, open hardware
  • Complete software development environment on board
  • Reusable design for embedded computing (to enable TTT!)

Hardware Detail Edit

  • Open hardware and software (no big SW license fees!)
  • Simplified backplane bus using 1Mbps SPI for low cost
  • On-board power management for long battery life (50mW while decoding MP3s)
  • 128x64 pixel onboard LCD, possibly VGA or NTSC output in next version
  • Projected system cost in volume O($50), easy to integrate into a cheaper few-chip solution

Built-In Networking Edit

  • Standards-based (TCP/IP)
  • Everything peer-to-peer:
  • Wireless LAN: 900MHz, 1mW, 200Kbps peering or hub-and-spoke internet gateways
  • RS-485 wired LAN: 1Mbps multidrop. Ethernet consumes too much power, Cat-5 cable is too expensive
  • Easy transition between connected? or detached modes

Software Applications Edit

  • Software Footprint: < 1MB!!!!
  • Web browser, full TCP/IP software suite, NFS, web server, etc.
  • Native or cross-compile -- either way a full software development environment: vi, emacs, C and Scheme
  • MP3 audio and IP telephony support in hardware
  • Browse or navigate with onboard buttons and wheel; write code with external keyboard/mouse

Hardware Reuse Edit

  • Cheap embedded controller for tasks bigger than a PIC can handle
  • Embedded routers, wireless gateways, data loggers, process controls, info displays, toasters, thermostats, robotic pets, ?
  • Everybody owns all software IP through GNU Public License (hardware is ML licensed)
  • Design is scalable through Motorola ColdFire 50MIPS solutions or Verilog 68K models

PDA System Architecture Edit

Four reusable main modulesEdit

  • Processor core containing Motorola Dragonball, 8MB flash, 8MB DRAM, running Linux
  • Mothercard containing audio DSP, 200Kbit/sec TDMA/FDMA data radio, backplane bus controller, and up to 64MB removable flash
  • Removable user interface board
  • Docking station containing battery charger, serial port, keyboard port, RS-485 multidrop network

External links Edit

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