Dependant on what you want the carpenter to make and how many you need just use dark cable on the export bus and place a level emitter nearby. I used that system to auto craft impregnated sticks for frames for bees. You get an excess of sticks every crafting cycle but these are eventually used up before the next cycle kicks in.
The problem with dark cable is that when it changes it reset the entire craftingline. Its better to put level-emitter on the export bus.