turtle as an observer

local version = 20240209.0800

--[[
    https://pastebin.com/sfY74BVX

    To install from turtle use:
        pastebin get sfY74BVX startup.lua

    OR copy this source code and save as startup.lua

    startup script for turtle used as an observer.
    No tools, no fuel required
    Modem placed behind with network cable to remote computer/turtle
    Transmits "waiting" until block detected below, in front, to right or left
    Message changes to "complete"
]]

local modemPosition = "back"    -- change as required for alternative positions "front", "top", "bottom", "right", "left"

local function clear()
    term.clear()            -- clear display
    term.setCursorPos(1,1)  -- reset cursor
end

local function wait()
    -- wait for bamboo to grow approx 10 - 15 mins for full growth to level 10
    -- wall / piston mechanism pushes dirt block upwards OR turtle/modem
    local time = 0
    local waitTime = 5
    local message = "waiting"

    while true do
        clear()
        -- following code for display purposes only so min/mins and sec/secs is correct
        print("Message broadcast: "..message)
        local mins = math.floor(time / 60)
        local secs = time % 60
        local output = "Waiting for bamboo growth:\n"..time.." seconds ("..mins.." minute"

        if mins ~= 1 then  output = output.."s" end
        output = output..", "..secs.." second"
        if secs ~= 1 then  output = output.."s" end
        output = output..")"
        print(output)
        sleep(waitTime)         -- sleep for 5 secs
        message = "waiting"
        if turtle.detect() or turtle.detectDown() then
            message = "complete"
        else
            turtle.turnLeft()
            if turtle.detect() then
                message = "complete"
            end

            turtle.turnRight()
            turtle.turnRight()
            if turtle.detect() then
                message = "complete"
                time = 0    -- reset timer
            end
            turtle.turnLeft()
        end
        rednet.broadcast(message)

        time = time + waitTime
    end
end

local function main()
    rednet.open(modemPosition)
    print("modem opened on '"..modemPosition.."'")

    wait()
end

main()