Sorry for the lack of updates lately, life gets busy.
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I switched to a different camera, I have no idea what brand it is or where to get it, there is no markings on the PCB or case.
But this camera has something the others did not, it uses a SHARP chipset which has a pin on the PCB that if driven high will mirror the image inside the camera. No software or other tricks needed. It also has a VERY wide field of view. Unfortunately it sucks at night.
I made the bracket out of aluminum stock, and powdercoated it with my DIY powercoat gun.
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Here is the Composite to VGA converter.
I had to add a second ground loop isolator before the converter as it was adding noise before the Amp.
I added a second 3.5mm jack in the back to relocate the IR receiver, and another jack to re-route the power button.
The actual converter is hidden in the dash, everything is done by remote.
The converter stays in VGA mode anytime it is off, and turns on to the previous source when it is powered up. So I just turn it on to see the reverse camera.
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This is the circuit that drives the power button on the VGA converter.
What this circuit does is automatically press the Power Button on my Composite to VGA converter twice: Once when I change into reverse, and a second time when I go back into drive. This changes my LCD monitor over to the rear-view camera (Composite), and then back over to my CarPC (VGA) automatically.
The circuit is basically two very simple Resistor/Capacitor (RC) timers.
Each circuit works on the property that as the charge in a capacitor increases the DC resistance and current decreases.
This circuit is simple and the components don't have to be exact. It is cheap, simple to build, and doesn't require any regulators or integrated circuits.
I do not have values filled in, as I usually just experiment with values until I find some that work well.
But, the larger the capacitor the longer it takes to charge and the longer the pulse output. Since the switch on my VGA converter is momentary, only a brief pulse is needed. Somewhere in the neighborhood of 150uF capacitors, and 1K resistors. The drain resistors can be very small, 100ohms or so.
Circuit design: I choose not to use any complicated microprocessors or timers in the circuit for a few reasons: This circuit is super easy to build, has minimal parts that may fail, and doesn't require a PCB. The circuit is designed as two self-reseting timers. Each timer sends out a single pulse to activate the power switch on the VGA converter.
Initial Circuit operation:
When the circuit is first installed, +12v Battery charges up the C1 capacitor, though R1.
Once C1 charges up fully the current across it will drop to nearly zero and it will remain trickle charged by the car battery. Unless your capacitor is defective there is no risk of draining your car battery using this technique.
Normal operation:
When you change the car into reverse, power is sent to the Reverse lights on your car.
This voltage will two two things when it passes into the circuit: First, it will energize both relays. This will discharge circuit C1 through R3, effectively resetting this part of the circuit.
The second process is that C2 will begin to charge up through R2 and RLY2.
This will makes RLY3 close until C2 is fully charged. This effectively presses the button on the VGA converter, switching it over to the rear view camera signal. Once C2 is fully charged RLY3 will reset back to a open position.
When you switch from Reverse back into Drive, C1 will begin to charge up again. This trips RLY3 a second time, switching the convector back over to the VGA signal.
Once there is no longer power from +12v Reverse Lights: C2 will discharge though R4. This will reset this part of the circuit and things can start over the next time you switch into reverse.
Sorry for the overly detailed explanation but it may help some users.
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Currently my only problem is that my car briefly flashes the reverse lights when you move the shifter from Park through Reverse to Drive.
The VGA converter is not fast enough to switch on and off this quickly, so it sometimes gets stuck in Reverse camera mode.
I am trying to figure out a good way around this.
Right now my best idea is just to add a simple button on the dash, that will let me just switch between the camera and normal operation at will.
Linear Mode
