startup

t=term
side="left"
term.clear()
x,y=t.getSize()
text="Use the arrow keys to change the radio's volume!"
t.setCursorPos(math.ceil((x-string.len(text))/2), 1)
t.write(text)
t.setCursorPos(math.ceil((x-string.len("Volume Level"))/2),2)
t.write("Volume Level")
HalfX=math.floor(x/2)
for i=1,16 do
  term.setCursorPos(HalfX-1,i+2)
  term.write("[ ]")
end
term.setCursorPos(HalfX,11)
term.write("-")
Selection=7
rs.setAnalogOutput(side, 7)
while true do
  event, Key=os.pullEvent("key")
  if Key==200 then
    if Selection~=15 then
      Selection=Selection+1
    end
  elseif Key==208 then
    if Selection~=0 then
      Selection=Selection-1
    end
  end
  rs.setAnalogOutput(side, Selection)
  t.setCursorPos(HalfX, 19-Selection)
  t.write(" ")
  if Selection~=15 then
    t.setCursorPos(HalfX, 17-Selection)
    t.write(" ")
  end
  t.setCursorPos(HalfX, 18-Selection)
  t.write("-")
end