send

local component = require("component")
local modem = component.modem
local event = require("event")
local sides = require("sides")
local redstone = component.redstone
modem.open(78)
perc = 90
while true do
  event.pull("redstone")
  if redstone.getInput(sides.back) == true then
    perc = perc + 1
  elseif redstone.getInput(sides.left)
    perc = perc - 1
  end
  sleep(0.5)
end