Thread: light sensor, etc -> game port inputs

Yep. You can use the gameport or a gamepad for just about any basic input, but I wouldn't suggest it for output of any kind or an accurate analog input. It's quite susceptible to RFI. For 12V detection I use a resistor and transistor, and for buttons it's just direct. I wouldn't use a photo resistor for dimming the screen, but all you need to do is calibrate by holding your finger over it and shining a light at it to get a good range. For dimming, what I have is a connection to the instrument panel dimmer that came off the HU connector. Here's a pic of what it looked like at first. Jjust think of it as a normally closed relay because it's kinda backward, and that white thing is a 2-pin connector to the dimmer line. Without power to the relay, the backlight inverter is powered by the lilliput, and when the lights are on they power the backlight through the 33 ohm resistor.

Hello.
Sorry but I was out these days.
I wasn't talking on using direct conections. For the dimming I could use a photo resistor but whith its own circuit trigering a relay, that would make grider to activate 'gama control'.
All the conections can be made through relay's.
But, of course, it would be easier to simply conect it to the instrument panel dimmer.

Thanks

I am thinking about pretty same. Have you guys considered using LPT port for ON-OFF like events?

The hard-wired backlight thing keeps the dark colors from looking grey and lighting up the inside of the car at night so I like part of it. Dark and somewhat adjustable.

I've been playing with voltage comparators recently and saw a good circuit for using a photodiode here on page 16 I think. R2 should be variable though, and using an LM311 you can reverse the output easier because it has a built in output transistor.

mpattonm, I don't have an LPT port, but I hear it's hard to read it on XP.

yeah, but we dont need a Lpt port. we can do it all with a joystick port.
with one axis we can use for the steering well or other remote like sony, and with the other axis we can put diferent resistors in paralel each one with a mini relay to act like a input port. that's what I was talking about.

Alex.

It's actually real easy to do all this without relays. The first circuit is a photoresistor, variable resistor, and a comparator (LM339). The joystick button goes on or off when the photoresistor's resistance goes above or below the variable one. The second one goes on/off when the 12V input goes on/off.

yes, thats a good option, but that is for a button connection.
I think it has to be with a relay if I want to use it with an x axis or a y axis (using grider with the joypad plugin) because I need to put several inputs on a single axis (the other will be used for the sony remote that acts also like a variable resistance on key press).

For the inputs conection I will need 2 120K resistors. Connecting those between 5V and the X and Y input (even without the sony stick) will supply somewhere around 2.5V to X and Y and act as a basic joystick to make the windows driver see a valid 2 axis joystick connected and centered (sort of) so it will load. Then with the sony stick connected and a button pressed it's like the 120K + another resistor in parallel lowering the resistance (each button is a different value and no press = open or 120K).

Right. But if you connect a relay and resistor to the X input and that's the same as the steering wheel, it would change that value and all the steering wheel values would be offset at night (or day, depending). I don't know if the plugins handle it, but having button on or off for light/dark would be simpler.