Microcontroller › 8051 › Monitoring a slow pulsing input bit, pulse every 1 sec or 3 sec, Ideas? › You can use 74HC590 8-bit
You can use 74HC590 8-bit binary counter, i tried it on arduino mega it worked fine. It can detect pulses in any pattern and length. Additionally you can use 74HC595 to reduce pin count that binary counters need.