Project Help: sensor to control when screen turns on/off

Please scroll down to see an update/better explanation of my project.

Thank you!

I wonder about the use of an IR sensor. If that's supposed to be triggered by the screen, you need to ask how much IR does the screen emit? Most lcd screens are doing their best to run at low power, and they are probably designed to emit only in the visible light range. Why don't you place a photoresistor near the screen (situated so that it doesn't see ambient light) and use that to detect screen on/off?

Hello,

Project Goal Concept: Speedometer hits zero --> Trips sensor --> Turns on screen attached somewhere in the car I am trying to determine if I can set up some type of sensor in my car to turn on a screen ONLY when the speedometer hits zero. Anything other than zero will cause the screen to be off.

Project Goal Ideally: I would like a sensor to "wake" the screen on a tablet ONLY when the speedometer in my car hits zero. I feel like this will present a larger hurdle, so I am open to solving the concept first.

Right now I feel that I should be able to complete this task with an IR sensor, but I am open to other ideas/other sensors.

Also, I am open to any suggestions for "waking' the screen of a tablet based off of the sensor being tripped.

Any suggestions are greatly appreciated!

Thank you

It's possible to edit a post after it has been made. It's against the forum rules to start two threads on the same topic.

DuaneDegn: It's possible to edit a post after it has been made. It's against the forum rules to start two threads on the same topic.

Thanks.

Do you have any suggestions though?

Well, you need to tap into the speedometer line on your car, or install your own. A hall effect or prox sensor near any metal part of the driveline will work.

A downward-pointing sensor looking at the road, like a big version of a computer mouse, would work fine, until a speck of mud hits the lens.

Perhaps a GPS-based solution might be easier to detect the car's actual motion.

MorganS: Well, you need to tap into the speedometer line on your car, or install your own. A hall effect or prox sensor near any metal part of the driveline will work.

A downward-pointing sensor looking at the road, like a big version of a computer mouse, would work fine, until a speck of mud hits the lens.

Perhaps a GPS-based solution might be easier to detect the car's actual motion.

I really like this, I think i can utilize the hall effect for the purpose of my project.

I am willing to determine success of this project if it is built outside of a car as well, so we don't have to worry about mud just yet.

But does this mean you don't believe an IR sensor will work if I set it up so that it trips the beam as the arm hits zero?

You want to have a sensor sit behind the face of the speedometer watching the needle? Sounds like a fun project but not the way I'd do it. Good luck with that.

After thinking this through, I think the GPS is the easiest way to do it.