while coding yet another DCF77-Decoder, I encountered another problem with my at169V-Based butterfly. I want the DCF-Signal to fire an interrupt at my MCU each time the state changes.
For this, I connected the DCF77-signal to PortD1 (INT0). In the code, I defined a interruptvector for EXT_INT0, declared PortD1 as Input with pullups turned on, enabled the EXT_INT0-Interrupt in the EIMSK-Register and defined INT0 to fire interrupts on logical state change in the EICRA-Register, globaly enabled interrupt by setting Interrupt-flag in the Flagregister (sei) and let the code end in an infinite loop. The Interruptroutine toogels another Port-PIN previously declared as output to display interrupt-occurance.
Question: is there anything I missed, that no Interrupt is fired? Does anyone have a sample code for me to look at?