You can also use MirrorOp. MirrorOp
I am using it at school for presentations. The sender software is on my Note 10.1 and the FREE receiver is on the PC which is connected to the OHP. The sender is only $10 and you can get it on the Play Store. Works over WiFi.
Note: Get the Galaxy version NOT the general android version as I have tried both and the Galaxy version works much better.
Omnia I900 (Khuanchai custom ROM 21928/23016)
Omnia II (My Own JH2/23689 Lite Custom Rom)
Galaxy S III 16 GB (ZSEMI1 ROM, Siyah-s3-v1.9.1 kernel)
Galaxy Note 3 (N900) - Rooted, Unlocked, ZSUDNE3 (Custom ROM)
Galaxy Note 10.1 (2014), SM-P601 - Rooted, TWRP, ZCUCNE2 Custom ROM
If you like my work, Donations Happily Accepted.