Methods and apparatus for performing timed functions in battery-powered, wireless electronic devices, such as sensors or control modules. Such electronic devices comprise a main processor and a co-processor. When the main processor enters a quiescent state in order to preserve battery life, one or more timed functions are transferred from the main processor to the co-processor just before the main processor enters the quiescent state. When the co-processor determines that it is time to perform the timed function, the co-processor wakes the main processor in order for the main processor to perform the timed function.