If you want to blink an LED once every second, you could use just about any old timer circuit to create a 1 Hz signal. Or, you could go the complicated route like [Anthony Vincz] and grab 1 Hz off ...

The SKY13292-365LF, a 4 x 2 switch matrix, combines a digital decoder with the RF switching network and tone/voltage detect within a lead-free, RoHS-compliant QFN plastic package ...