Zitat Zitat von Willa
... wäre zur zeit des interrupts der Pegel doch genau bei 2.5V ...
Das Problem hatte ich auch mal gewälzt. Und dann gelesen:
Zitat Zitat von ATM[size=1
[/size]EL-doc 8161D–AVR–10/09]The External Interrupt 0 is activated by the external pin INT0 if the SREG I-flag and the corresponding interrupt mask are set. The level and edges on the external INT0 pin that activate the interrupt are defined in Table 12-2. The value on the INT0 pin is sampled before detecting edges. If edge or toggle interrupt is selected, pulses that last longer than one clock period will generate an interrupt. Shorter pulses are not guaranteed to generate an interrupt. If low level interrupt is selected, the low level must be held until the completion of the currently executing instruction to generate an interrupt.
Und dieses Sample untersucht dann jemand . . . nehme ich an.