function redstonePulse(side)
    local status = redstone.getOutput(side);
    redstone.setOutput(side, not status);
    os.sleep(0.05);
    redstone.setOutput(side, status);
end

local readyChestSide = "top";
local beltInvertorSide = "back";
local seedInputSide = "bottom";

local grownCrystalName = "appliedenergistics2:purified_certus_quartz_crystal";

--local monitor = peripheral.wrap('right');
local belt = peripheral.wrap('right');
local items
--monitor.setCursorPos(1,1);
--monitor.setTextScale(0.5);
redstone.setOutput(beltInvertorSide, false)
--monitor.write('Detecting...');
redstone.setOutput(readyChestSide, true);
redstone.setOutput(seedInputSide, true);
local ticksWithoutItem = 0;
print('Detecting')
while true do
    items = belt.list();
    if #items > 0 then
        ticksWithoutItem = 0;
        --monitor.clear();
        local item = belt.getItemDetail(1);
        if (item.name ~= grownCrystalName) then
            print("Crystal is not ready, another iteration");
            redstone.setOutput(beltInvertorSide, true);
            os.sleep(4);
            redstone.setOutput(beltInvertorSide, false)
        else
            print("Crystal is ready!");
            redstonePulse(readyChestSide);
            redstonePulse(seedInputSide);
        end
    else
        ticksWithoutItem=ticksWithoutItem+1;
        if (ticksWithoutItem > 600) then
            print("No items detected on the belt for 600 ticks, requesting another item");
            redstonePulse(seedInputSide);
            ticksWithoutItem = 0;
        end
    end
    os.sleep(0.1);
end