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I want to detect when a Scalextric car passes a certain point on the track
I've seen this dome with a light source above the track and something set into the track to detect when the car passes
I understand this is done using a light sensitive transistor set into the track and connected to the joystick port.
My questions:
Is a light sensitive transistor called something else because I can't track any down?
How does it connect to the joystick port?
Thanks
I don't think it's a small little box you just buy in a general store.
The joystick port is also a midi port and can thus receive data from any device that can send data (and apps listening to the midi/game port can act on it).
How it's connected to the midi port or lpt/com. I dunno. If you want to try such a project you might first want to go and buy the parts required (and a soldering iron) as you would probably have to put it all together yourself.
Pin layout and such is important and it's either documented by the company making the PCB/Sensor units or you'll have to figure it out yourself and develop your own communication application to communicate via those pin layouts (RX/TX/etc)
I've got one of those light sensor things somewhere, but I've forgotten what it's called too :)
AFAIK, light shining on it produces a current. Hence, it would need to connect to some sort of device, which then could connect to any port you wanted.
Do you have one, or looking for one?
OK, so I now know that it's called a phototransistor :thumb:
I have also tracked down a description of the joystick port
Actually a phototransistor changes resistance... and you have to use it with a transistor, kinda like this:Quote:
Originally Posted by penagate