Integrated BOM¶

UPDATED: 10-09-2010 to match rev5 hardware

Hardware¶

Using TV remote hardware - has excellent filtering to reject noise from fluorescent lights, other equipment etc.

• Permits us to interact with other IR hardware
  • Control a TV (Scout as a portable remote)
  • Use a universal remote as a joystick
  • IrDA data transfer from computers and PDAs

Driver code on ATMega128RFA1.

Transmitter¶

• TSAL6200 - recommended
  • Supply Current: 100mA
  • Viewing Angle: +/-17 deg (angle of half intensity)
  • Peak Wavelength: 940nm
  • Radiant Intensity = 500 mW/sr
  • Recommended in receiver datasheet

Receiver¶

• TSOP1138 - what we are using
  • Supply Current: 0.45mA
  • Transmission Range: 45m
  • Peak Wavelength: 950nm
  • Directivity: +/-45deg

• TSOP4838 - what we currently have on the electronics shelf
  • Supply Current: 1.1mA
  • Transmission Range: 45m
  • Peak Wavelength: 950nm
  • Directivity: +/-45degrees

Central Concepts¶

• Build the BOM into the board to free up physical space above the robot
• Achieve communication between BOM IR sensors
  

Protocol¶

• Specialized version of the Sharp protocol @ 38kHz
  
• First 6 data bits: Robot ID (64 possible values)
• Last 2 data bits: Emitter Position (4 possible values)
• 1ms per 0 bit, 2ms per 1 bit, 13 bits per broadcast, 13-26ms per transmit cycle (per channel)
• 40ms delay between same command (we will broadcast the 4 channels round robin to conserve power @ any instant)