How about blind spot monitor

The reverse camera used on the Prius has a very wide angle lens. If there's a car in your blind spot, when it's activated, it will show a portion of that car. The idea is to use turn signal to activate the rear camera to show blind spots while changing lanes.

Killing 2 birds with 1 stone. In addition to use the rear camera as blind spot monitor, I've also added the "http://priuschat.com/forums/gen-iii...enable-rear-camera-display-while-driving.html" function.
The switch I used is a 3 position ON-OFF-ON DPDT rocker switch.
ON - [Blind spot monitor Active] activates rear camera when left or right turn signal is activated. Activating hazard lights will not activate rear camera. When neither turn signals are activated, the reverse will activate the rear camera. Intelligent Parking Assist functions as usual as long as you're in Reverse.
Off- [Blind spot monitor Off] Operates like normal. Only Reverse will activate the rear camera. IPA functions as usual.
ON- [Enable rear camera while driving] Displays rear camera while driving forward. This reeks havoc on GPS map because it moves backwards. Turn off will resume correct GPS location in a few seconds.

Now on to the wiring.
You'll need 2x 3.3k mf caps 15v or higher, 3x SPDT relays, a 3 position DPDT rocker switch.
locate the turn signal wires at either front or rear turn signals or in the kickpanel http://priuschat.com/forums/gen-iii...bo-lights-signal-parking-courtesy-lights.html convert pulse to steady using this diagram Special Applications with SPDT Relays, Diagrams for both left and right. In addition to that diagram, ground 87a for both. The left and right turn signal now rest at ground. When either side is on, it will create a + and -. This is needed to activate the relay to activate the rear camera.
Connect both steady outputs of the left and right to the top terminals of the 3 position rocker switch. The bottom terminals goes to power and ground. The middle terminals goes to the 3rd relay's 85 and 86 terminal. The 3rd relay's 87 goes to +12v (this activates the rear camera) 30 goes to the radio side of the reverse signal wire. 87a goes to the car side of the reverse signal wire. The reverse signal wire is the pink wire on pin 5 of the gray plug behind the nav screen.
Enjoy and have fun. Questions and comments are welcome.

 

Of course that's the still safest thing to do. I'm a creative installer so I like to do stuff that others haven't thought of..

 

traditionally, the passenger blind spot is easier to see but the driver side is harder. luckily for the NA the camera is on the left side of the license plate. I got a chance to really try it out today. it shows 3/4 of the vehicle in the driver blind spot and half of the vehicle on the passenger side. overall I love this mod. it only took an hour to do using parts laying around my garage. I have a bad habbit of not using the turn signal for anything. With this mod, i use the turn signal every chance i get.

 

You can use 1 DPDT relays for each camera and the turn signal will automatically switch on the correct camera. I already prewired mine to do this. Since I didnt use aftermarket cameras, I had both activating the rear camera instead.

My original plan was to install 5 cameras; 1 in the front to show what's immediately in front of the car. This gets activated when the vehicle speed drops below 10mph. 1 in each of the front corner to monitor front cross traffic and blind spots. This is possible with 120 degree wide angle lens. They are activated by the turn signal. 1 in each of the rear corner to monitor rear cross traffic when backing out of a parking spot. Rear corner cameras are activated by reverse gear and activating the corresponding turn signal. When no signal is activated, only the rear camera works and IPA also works.
Due to me being lazy and lack of funding and time, I took the shortcut.

I had the caps, relays and the switch from previous projects so this was done at no cost to me. However, I did spend $20 on those components on the previous project a couple of years ago. The rear camera takes about a second to switch on after activating the turn signal. It takes about 2 seconds for the camera to turn off after deactivating the turn signal. This is about as close as you can get to a blind spot monitor without spending large amount of money. In fact, I'm not sure if there is such a thing available aftermarket besides custom build it out of reverse cameras.

 

I suck at graphics but I'll do my best but it'll have to be in a day or 2. I'm taking a 250 mile trip today. It'll be the first time I can truly test it out.

My initial test shows that you don't need a steady signal to trigger the camera. A pulse signal would also trigger the camera. However, the relay clicking on and off would drive me crazy. Also with pulse signal, it could confuse the nav screen and possibly lock it up. I doubt it though. Using a diode from each side of the signal will not disable hazard light triggering the camera. So, if you want hazard lights to trigger the camera, you can use diodes from both sides of the turn signal and feed both pulse signals to 1 cap/relay.

The reason why hazard lights on my setup don't trigger camera is because when both signals are flashing, the pulse to steady will convert both sides to +. The 3rd relay's coil terminals will both get + and won't trigger the coil. Remember my instruction "convert pulse to steady using this diagram Special Applications with SPDT Relays, Diagrams for both left and right. In addition to that diagram, ground 87a for both." The 3rd relay's coil terminals are resting at ground. When 1 signal is activated, it turns 1 side + and triggers the 3rd relay. when both sides are activated like the hazard lights, the relay's coil is resting at +12v and won't trigger the coil. I know I'm keep repeating myself but I'm trying to explain it the best I can.

 

Yes I have, read post #7

 

What you are trying to accomplish? activating the camera when you hit the brakes? I'm the opposite. I love working with 12v DC and hate 110v AC. I just don't like getting shocked. With DC, you don't get shock. The only thing you'll fry when hooked up wrong is the component.