[lua][help]Making a timer (more detail in the description)

How to make a timer that will count down if it has receive a specific message from another computer using the modem and that it will keep waiting for the same message and count down every time it received the same message. It will also be nice if the number was displayed on a monitor screen. Also if the number hits zero it will output a redstone signal.

I have been trying to figure this out for at least 2 days but i think i lack the knowledge to program such a task can you please help me. Thank you in advance. I have figured out on how to send messages using the modem but i just don't know how to do the timer.

Can you post what you have. You're probably on the right track and then we can help you from there :)/>

Do you mean something like this?

If the computer receives a message like countdown it will begin a countdown

rednet.open('right')
while true do -- infinite loop
  senderID, message = rednet.receive()
  if message == "countdown" then -- if it receives a messag econtaining 'countdown'
    for i = 10, 1, -1 do -- counts down from 10 to 1, -1 is the step
      term.setCursorPos(1, 1)
      term.clearLine()
      print(i .. (i == 1 and " second" or " seconds")) -- basically an if statement within the print function
      sleep(1)
    end
  end
end

I am using three computers. One of them is a turtle and the other two are computers.

turtle (id 14)

function down()
   rednet.open("right")
   if turtle.down() == true then
	   rednet.send(7, "down")
	   shell.run("new") -- rerun the program
   else
	   rednet.send(7, "no")
	   shell.run("new")
   end
end
rednet.open("right")
id, message = rednet.receive()
if message == "down" then
  down()
end

computer #1 (id 7) The main purpose for this computer is to control the turtle

rednet.open("right")
rednet.send(14, "down")
id, message = rednet.receive()
if message == "down" then
	print("turtle has successfully go down")
	rednet.send(9, "down")
elseif message == "no" then
	print("turtle cannot move down")
end

computer #2 or the timer (id 9)

I have no clue on how to start this one. Sorry for my noobish programming or if it's really hard to understand.

I want it to subtract a number every time it receives the message.

Oh is that what you're trying to do… mm well each time it succesfully moves down, you can
use simple math to decrease a variable by one:

times = times - 1

Also, for the turtle program, you do not need to shell.run() the program over and over,
instead use a infinite loop

-- turtle code (id 14)

rednet.open("right") -- only need to open it once.

function down()
    if turtle.down() then -- with booleans, you do not need to compare them with false or true, you can simply do this and if not turtle.down() then (false)
        return "yes"
    else
        return "no"
    end
    --[[
        A simplier way of doing this can look something like this:
        
        return turtle.down() and "yes" or "no" -- should work.
    --]]
end

while true do -- infinite loop
    id, message = rednet.receive()
    if message == "down" then
        work = down()
        rednet.send(7, work) -- will send yes or no to computer id 7
    end
end

-- computer #1 (id 7)

rednet.open("right")

-- Not sure if you want an infinite loop here
rednet.send(14, "down")
id, message = rednet.receive()
if message == "yes" then
    print("Turtle successfully moved down.")
    rednet.send(9, "down")
elseif message == "no" then
    print("Turtle failed to move down."
end

computer #2 or the timer (id 9)

-- Not sure what the code is here but when it receives 'down' then decremt a value:

times = times - 1

so for computer #2 the code will be

rednet.open("right")
local times = 4 -- example
id, message = rednet.receive()
if message == "down" then
times = times - 1
print(times)
end

but how will it keep counting down the changed value everytime it receives the same message do i have to retype it or is there a better way? I tried using a loop but it keeps printing the number and an error appears.
bios:141: Too long without yielding

This is the coding that i used that keeps making that error

rednet.open("right")
function down()
local count = 4
if message == "down" then
  count = count - 1
  print(count)
end
end
id, message = rednet.receive()
while true do
down()
end

Also thank you for teaching me some tricks or tips to make my coding a lot easier =D

ThrowTheCheeze, on 11 January 2013 - 11:53 AM said:

so for computer #2 the code will be

rednet.open("right")
local times = 4 -- example
id, message = rednet.receive()
if message == "down" then
times = times - 1
print(times)
end

but how will it keep counting down the changed value everytime it receives the same message do i have to retype it or is there a better way? I tried using a loop but it keeps printing the number and an error appears.
bios:141: Too long without yielding

To make it keep doing the code so it will never stop, use a while loop:

rednet.open("right")
local times = 4 -- example
while true do
  term.setCursorPos(1, 1) term.clearLine()
  print(times)
  id, message = rednet.receive()
  if message == "down" then
    times = times - 1
  end
end

ThrowTheCheeze, on 11 January 2013 - 11:53 AM said:

This is the coding that i used that keeps making that error

rednet.open("right")
function down()
local count = 4
if message == "down" then
  count = count - 1
  print(count)
end
end
id, message = rednet.receive()
while true do
down()
end

Also thank you for teaching me some tricks or tips to make my coding a lot easier =D

It gives this error if you do not let the program yield (pause) within 10 seconds or so.

But you should rather change your code to this:

rednet.open("right")
count = 4

while true do
  term.setCursorPos(1, 1) term.clearLine()
  print(count)
  id, message = rednet.receive() -- put the rednet.receive() within the infinite loop so it will keep listening.
  -- In this case, a function is not needed and you can simply do this
  if message == "down" then
    count = count - 1
  end
end

Thank you for your service. I really appreciate it now all i have to do is learn how to display it to monitor screen and you don't have to show it to me i wanna learn by myself but thank you for your tips it helps me a lot. :lol:/>

Haha, have fun :)/>

Mainly look at the peripheral api for this.

So this will be my code for the timer

rednet.open("back")
monitor = peripheral.wrap("top")
term.clear() term.setCursorPos(1,1)
local ylevelt = 0
local fuel = 0
term.write("Enter the fuel level of your turtle:")
fuel = read()
term.setCursorPos(1,2)
term.write("Enter the ylevel of your turtle:")
ylevelt = read()
function ylevel()
  monitor.setCursorPos(1,2)
  monitor.clearLine()
  monitor.setTextColor(colors.yellow)
  monitor.write(ylevelt)
end
function tfuel()
  monitor.setCursorPos(1,4)
  monitor.clearLine()
  monitor.setTextColor(colors.yellow)
  monitor.write(fuel)
end
function counts()
  ylevel() --to display on screen
  sleep(.5)
  tfuel()
  while true do
    id, message = rednet.receive()
    if message == "down" then
	  ylevelt = ylevelt-1
	  ylevel()
    elseif message == "fdown" then
	  fuel = fuel-1
	  tfuel()
    end
  end
end
---------Main Program
monitor.clear()
monitor.setTextScale(1)
monitor.setCursorPos(1,1)
monitor.setTextColor(colors.blue)
monitor.write("Current estimated y level:")
monitor.setCursorPos(1,3)
monitor.setTextColor(colors.blue)
monitor.clearLine()
monitor.write("Current fuel level:")
counts()

Thank you! It is finally working i tested the program so many times by now :lol:/> and it finally worked thank you for your help! I also put a script on my turtle to dig if there is a block and maybe make it more advance by asking for fuel if needed and now I will try to learn on how to make a menu on my command computer (The one that controls the turtle) Wish me luck :D/>

Good to know it's going good :P/>

With regards to a menu, I'd suggest for you to use tables with the options, even if there is only 2 options. It's much easier to work with (imo).

Goodluck and don't be shy to come back for more help :P/>