Hi guys. I just had another project i just thought up and was wondering if anyone would know what i need to make it work.

first i want to trigger a DBC battle cuircit with a IR motion sensing Trigger for the lack of knowing what the term would be.
Second I want the Battle cuircit to continue firing every 3-5 seconds until it is either disabled or the target moves out of a fixed field of fire.
I have the 21st Century /german halftrack with the Pak 40 and I have just the Pak 40 by it slf.
I want it to work completely on its own. Thus needing a Triggering system.
Can anyone help me figure out what i need and how to go about it.
I plan on using just a basic simple DBC, but agian it needs to be triggered by IR motion.