getting a handle on everything, still having trouble getting my mind around the hardware part...here's a scenario:
I want to map all the keys on the keyboard to their own light - code-wise i'm fine but i'm not sure how to do this with hardware (i have the duemilanove) - I have the 74HC595 chip, and that gives me 8 additional outputs;
what would be required to get like 100 outputs, one for each key on the keyboard? I assume i could use multiple chips or one chip that has 100 outputs, but not even sure that exists.
I want to map all the keys on the keyboard to their own light
What keyboard? And what light?
what would be required to get like 100 outputs, one for each key on the keyboard?
Aren't keyboards usually input?
is there a limit on the number of digital outputs one arduino board can handle?
The Duemilanove is physically limited to 20 outputs (18 if you skip the serial lines). The Mega is physically limited to 54. However, neither can handle much in the way of current (power).
Components like shift registers and techniques like multiplexing can extend both of those significantly.
I suspect you have some kind of keyboard (which will require a scanning matrix) and some lights (which will require multiplexing and external transistors for power).
just a standard computer keyboard, the one i have at work - any keyboard that when pressed will be able to be detected by the arduino.
standard LED lights, maybe rgb ones but not picky.
Aren't keyboards usually input?
i would like to map each key to an individual LED; 100 keys > 100 lights
The Duemilanove is physically limited to 20 outputs (18 if you skip the serial lines). The Mega is physically limited to 54. However, neither can handle much in the way of current (power). Components like shift registers and techniques like multiplexing can extend both of those significantly. I suspect you have some kind of keyboard (which will require a scanning matrix) and some lights (which will require multiplexing and external transistors for power).
Okay so I'll look into multiplexing and shift registers. Thanks for any other help!