span.lua

--- emulating Three Sisters' SPAN control

-- input 1 == frequency
-- input 2 == span

-- output (1,2,3) == low, centre, high

function init()
  input[1].mode( 'stream', 0.01 )
  for i=1,3 do output[i].slew = 0.01 end
end

input[1].stream = function( v )
  local span = input[2].volts
  output[1].volts = v-span
  output[2].volts = v
  output[3].volts = v+span
end