Ok here it goes...
I have a projector remote that is dying, and i cannot buy a replacement. Is there a way to build a arduino circuit to capture, store the existing codes from the dying remote. Then replay them?
Yes that is possible. However it would be a whole lot easier if you could find out what codes the remote uses so you don't have to have the code learning/recording process to deal with. There are lots of remote IR codes published on the web, perhaps if you stated the manufature and model number of the projector someone might have a link to a database of remote IR commands for it.