If the Bittle board is the old board NyBoard V1_0, you can Download the Bittle basic kit course source code here:
Bittle basic kit course source code.zip
If the Bittle board is the new board NyBoard V1_1, you can Download the Bittle basic kit course source code here:
http://files.seeedstudio.com/Seeed_EDU/Course_documents/Bittle%20basic%20kit%20course%20source%20code.zip
You can Download the Bittle sensor pack course source code here:Bittle sensor pack course source code.zip