When we were building and testing 10 OpenROV 2.7 kits in Oslo last weekend we noticed several times that the digital feeds could get mixed up. It sounds absolutely crazy but you could see the video feed from an ROV that you weren't connected to via tether and sometimes even control it after a fashion, for a while. After ruling out wifi shenanigans we think that the tethers might be acting like antennas and the Tenda-adapter cards are finding the weak signal and tuning in on it.
When we were outside testing the completed ROVs the problems reoccurred and disturbed operation.
I think we can neutralize the confusing part of this problem by simply setting the different ROVs to different IP-numbers. That would make the cockpit-webserver-adresses unique for the different ROVs, ensuring that your computer only talks to and listens to the correct ROV. What this solution might NOT solve is that the Tenda-filters could be tuning in on the wrong signal. That could then result in lost contact with your tethered ROV, but at least you would know it! A possible workaround if that part of the problems persists could be trying to use the Pairing function on the Tenda-plugs, according to their manual that adds a encryption to the signal. But that functionality might be lost when we hack the boards. (http://www.tenda.cn/tendacn/DownLoads/show.aspx?downid=1127)
Please let us know if you have had similar experiences or ideas and I'll try to do some experiments with changing the IP next time we have an Oslo OpenROV meetup.
All thoughts are welcome :)