Any Idea how to do? (I´m a beginner):
8 (or more) different buttons, each can be pressed a short (<0,6 sec.) or long (>= 0,6 sec) period of time. Depending on long or short press duration different outputs should be set or unset. Is it possible that more press-actions can be read (nearly) simultaneously?
Is it possible that more press-actions can be read (nearly) simultaneously?
That depends on which pins the switches are connected to. If all the pins are on the same port, you can use direct port manipulation to read all 8 pins in one operation.
http://www.arduino.cc/en/Reference/PortManipulation
Polling the pins using digitalRead, and tracking when the state changed, using millis() is not a difficult task. It simply requires the use of arrays to hold the previous switch state and the time of the last state change.
You will need to take switch bounce into consideration. Do you REALLY need such a demanding design requirement? Say a bit about what your project is for, and ideas may come your way.
See....
... for a not very good discussion of switch bounce. Or search with Google... you don't need to limit yourself to switch bounce with an Arduino, it is a general problem.
Thanks tkbyd and PaulS for your answers. I´ll try to explain my idea:
At home I´ve an installed Controll-System called LCN to control lighting and other home functions. (See http://www.issendorff.com/). Even if it is cheaper than EIB, expanding the existing system exceeds my financial potentials ;-). Therefore I´m looking for possible alternatives. And one option could be to devlop a system which is opensource (HW as well as SW).
So a lot more people could use it and a lot of more applications could be developed in the future. BTW: The LCN Systems (partly) uses Hig-Voltage (230V) I/O so that normal Lightswitches can be used within the house installation.
Please see the link above for more details and let me know how you think about this idea.