Inverted Redstone signal

OmegaVest, on 07 April 2013 - 12:26 PM said:

Spoiler

local on = false  -- So we'll know whether to fire the pulse or not.'

local function doTime  -- The pulse
  rs.setOutput("right", true)
  sleep(0.2)
  rs.setOutput("right", false)
end

while true do
  local tmr = os.startTimer(2.0)  -- Make a timer for 2 seconds

  local evt, arg1, arg2 = os.pullEvent()  -- Catch-all for our functions
  if evt == "redstone" then
	if rs.getInput("left") then  -- If left is on
	  on = true
	else  -- Or not.
	  on = false
	end
  elseif evt == "timer" and arg1 == tmr and on then
	doTime()
  end
end

And I did that in about a minute, give or take typing speed.

• BUG: you forgot the () on the function declaration
• IMPROVEMENT: the lines

if rs.getInput('left') then
  on = true
else
  on = false
end

that function returns true or false, why put it in an if statement to then just assign true/false to the variable, just assign the function call to the variable, even of you want to invert it you can do this by using 'not'
• BUG: I could have this never pulse by spamming other events (like key press) and your timer is always being overridden, so when it comes time to see if the timer has finished it will never validate because there is a new timer id in the variable… to fix this you should always start a timer before a loop, and then restart the timer once it has fired and you detect it.
• NOT MEETING REQUIREMENTS: the if statement to check to pulse the redstone says; if the event was a timer finishing, and the first argument was our timer, and the redstone signal on the left is ON, then pulse, OP clearly states they want it to pulse when there is no signal, so it needed to be 'not on'
• BUG: The on variable at the start should have been assigned based on the redstone signal on the left, just incase it was on when the program started up

local outputSide = 'right'
local inputSide = 'left'
local disable = rs.getInput(inputSide) -- 'so we know whether to fire the pulse or not.'

local function pulseSpawner()
  rs.setOutput(outputSide, true)
  sleep(0.2)
  rs.setOutput(outputSide, false)
end

local timeout = os.startTimer(2) -- 'make a timer for 2 seconds'

while true do
  local event, timer = os.pullEventRaw()

  if event == 'redstone' then
	disable = rs.getInput(inputSide)
	if not disable then
	  timeout = os.startTimer(2) -- 'restart our timer, we dont know how long it has been disabled for'
	end
  elseif event == 'timer' and timer == timeout and not disabled then
	pulseSpawner()
	timeout = os.startTimer(2) -- 'restart our timer'
  end
end