Tangible Computer Networking

How do you networking small inexpensive devices?

Wait for networking to get cheaper?

• Wired
  • USB
    • Already common in cameras and cell phones
    • Requires a four-wire cable
    • Supplies five volts
    • Pretty complex protocol
    • Well documented
• X-Base T
  • Seems a bit much
• Wireless
  • Bluetooth
    • Already common in audio for cell phones
    • Designed for personal area networks
    • Generally devices are paired
    • Extremely complex protocol
    • Documented by the Bluetooth Special Interest Group
    • Named after Harald I, king of Denmark
  • Wi-Fi and IEEE 802.11
    • The way to connect your computer or video game console
    • Designed for local area networks
    • Security protocols just as WPA
    • Controlled by the Wi-Fi Alliance

A lost of cheaper solutions

• wired
  • RS-232
    • DTE -- Data Terminal Equipment
    • DCE -- Data Circuit-terminating circuit
    • DB connectors
    • Handshaking: RTS/DTS and XON/XOFF
    • Bits: Start, data, parity, and stop
    • 3-wire RS232: transmit, send, and ground
  • I²C
  • SPI
  • 1-Wire
  • CAN
• wireless
  • CIR
  • IrDA
  • ZigBee

An off-the-shelf compromise

Lantronix servers allow simple communication protocols to implement the more complex protocols. Many other devices such as GPS modules or XBee modules also support a RS232 interace. These are controlled by extensions of the ancient Hayes command set.