xmpp with otr chat server and client

Question

I have a lab for class and I am suppose to implement a chat app that implements otr. There are a lot of tutorials that show how to add a otr plugin to give a current chat client otr functionality. However I would like to create as much of it from scratch as possible. I want to use a raspberry pi as a xmpp server and connect clients to that server. I am going to use a library like JSQMessagesViewController(iOS) or Applozic-Android-SDK(android) to create the chat framework. But I want to be able to use otr to encrypt and authentication.
How is the best way to implement this? Can someone please point me in the right direction.
Thanks