Asking the vendor to add an official RS485 module (an add-on daughter board) just for $10 is a good deal.
After that you can go to fleabay to buy a USB-RS485 dongle.
<< DIY Adding PC control to RJ10-10638 board >>
Use post #1, the linked picture as the reference:
On its top side, you'll find Rx and Gnd contact points.
Use my earlier thread as the reference http://www.cloudynig...-for-5-buttons/
1. Solder a 3.3K ohm resistor to Rx lead. The other side of 3.3K resistor goes to to TTL_Serial side of the dongle.
2. Solder a second wire on Gnd which will connect to TTL_Serial dongle's Ground.
Please note this board has different revisions and the soldering pad arrangements can be different than what I've described.
Just pick RX and GND for this purpose.
BTW, RJ10 is also known as EOSHD 802D, the AD converter used in that cam is also a 10-bit AD9943, like LN300's.
Edited by ccs_hello, 20 January 2015 - 10:06 PM.