Swarminer Turtle Recovery

--Work in Progres - turtle recovery program

local function yn(A)
    if not A then return false end
    local key
    write(A.."[y/n]:")
    while true do
        _,key = os.pullEvent("key")
        if key==21 then write(keys.getName(key).."\n") sleep(0.01) return true
        elseif key==49 then write(keys.getName(key).."\n") sleep(0.01) return false
        end
    end
end

local function getpos()
        local temp={}
        while true do
                print("Enter data from F3 Screen")
                write("Please enter x coordinate:") temp.x=tonumber(read())
                write("Please enter y coordinate:") temp.y=tonumber(read())
                write("Please enter z coordinate:") temp.z=tonumber(read())
                if temp.x and temp.y and temp.z then
                        print("x:"..temp.x.." y:"..temp.y.." z:"..temp.z)
                        if yn("Are thise correct?") then break end
                end
        end
        return temp
end

local channel=15151
modem=false
for _,i in pairs(redstone.getSides()) do
    if peripheral.isPresent(i) then
        if peripheral.getType(i)=="modem" then
            if peripheral.call(i,"isWireless") then
            modem=peripheral.wrap(i)
            --modem.open(channel)
            break
            end
        end
    end
end
local function transmit(...)
if modem then modem.transmit(...) end
end

if turtle.getFuelLevel()<=2 then return false end
--print("Give me coords in front of me")
turtle.forward()
local pos={gps.locate(2,true)}
if pos[1] then
    print("x:"..pos[1].." y:"..pos[2].." z:"..pos[3])
    if not yn("Are thise correct?") then return false end
    pos={x=pos[1],y=pos[2],z=pos[3]}
else print("No gps online - Enter Scanner Position manualy") pos=getpos() end
turtle.back()
transmit(channel,4,"Pause") sleep(1) transmit(channel,6,textutils.serialize(pos))
print("Recall in progress")

turtle.select(1)
turtle.dropDown()

while true do
if turtle.detect() then
while turtle.suck() do turtle.dropDown() end
    turtle.dig()
    turtle.dropDown()
else
    sleep(1)
end
end