--codeExampleStart 1 -----------------------------------------------------------
-- setupI2C() - sets up the specified port to handle an I2C sensor

function setupI2C(port)
  nxt.InputSetType(port,2)
  nxt.InputSetDir(port,1,1)
  nxt.InputSetState(port,1,1)

  nxt.I2CInitPins(port)
end

-- Now put the standard I2C messages into the nxt table

nxt.I2Cversion = { [2] = string.char( 0x02, 0x00 ),
                   [4] = string.char( 0x04, 0x00 ) }

nxt.I2Cproduct = { [2] = string.char( 0x02, 0x08 ),
                   [4] = string.char( 0x04, 0x08 ) }

nxt.I2Ctype    = { [2] = string.char( 0x02, 0x10 ),
                   [4] = string.char( 0x04, 0x10 ) }

nxt.I2Cdata    = { [2] = string.char( 0x02, 0x42 ),
                   [4] = string.char( 0x04, 0x42 ) }

-- waitI2C() - sits in a tight loop until the I2C system goes idle

function waitI2C( port )
  while( 0 ~= nxt.I2CGetStatus( port ) ) do
  end
end

-- Put it all together in a function that prints out a report of which
-- sensor is connected to a port

function checkI2C(port, address)
  setupI2C(port)

  nxt.I2CSendData( port, nxt.I2Cversion[address], 8 )
  waitI2C( port )
  print( "Version    -> " .. nxt.I2CRecvData( port, 8 ) )

  nxt.I2CSendData( port, nxt.I2Cproduct[address], 8 )
  waitI2C( port )
  print( "Product ID -> " .. nxt.I2CRecvData( port, 8 ) )

  nxt.I2CSendData( port, nxt.I2Ctype[address], 8 )
  waitI2C( port )
  print( "SensorType -> " .. nxt.I2CRecvData( port, 8 ) )
end
--codeExampleEnd 1

--codeExampleStart n -----------------------------------------------------------
--codeExampleEnd n