I'm posting this thread to explain how I managed, finally, to have a rear view camera that allows me to see behind my camper while driving. I've tried a few backup camera solutions and had some unacceptable results.
My requirements were:
1. Display vehicles far behind and in neighboring lanes (not common in backup cameras I've tested, they look down from 'on high')
2. Mirrored image... for example, when looking at the screen if a passing car is on the left, I can expect it to pass on my left. This function is common on backup camera but impossible to find on an action camera, or security camera.
3. WIFI - Strong signal strength because the camera is too far away for bluetooth.
4. The rear view display must be shown on my phone, not another monitor in the cab.
5. Cheap (in this instance free!)
I had an old cellphone that's no longer used. I ordered a
suction cup mount from Amazon for $4.99. This allowed me to attach the old phone to the rear window in my camper.
On this old phone I
installed IP Web Cam (free software). When it's run, on the screen it shows the web address to view the display on another phone, tablet or PC!
This cell phone needs to connect to the internet. This can be done by:
a) instead of an old phone I use my wife's which has an active cell plan
and use that phone's HOTSPOT (it creates it's own wifi) or
b) connect to the HOTSPOT on my current phone in the truck, or
c) connect to my truck's WIFI, or
d) connect to the router in my camper
I can select any of the above methods. Hopefully, you can find at least one... then open the web address on the phone in your truck (use same WIFI). This webpage shows various settings and most importantly in section titled 'Advanced', there is the option to "MIRROR". TADA!
Free (well, the mount was $4.99) but I could have attached the phone with duck tape to the rear window.