A wireless battery-powered daylight sensor for measuring a total light intensity in a space, the sensor comprising: a photosensitive circuit operable to generate a light intensity control signal in response to the total light intensity in the space; a wireless transmitter for transmitting wireless signals; a controller coupled to the photosensitive circuit and the wireless transmitter, the controller operable to transmit wireless signals in response to the light intensity control signal; and a battery for powering the photosensitive circuit, the wireless transmitter, and the controller, characterised in that; the controller is operable to sample the light intensity control signal to collect a first plurality of samples during a first time interval, and a second plurality of samples during a second, subsequent time interval, the first and second time intervals being non-overlapping, determine a minimum sample among the first plurality of samples, determine a minimum sample among the second plurality of samples; determine a maximum sample among the second plurality of samples, calculate a first adjustment percentage based on a difference between the minimum sample among the first plurality of samples and the minimum sample among the second plurality of samples, calculate a second adjustment percentage based on a difference between the minimum sample among the second plurality of samples and the maximum sample among the second plurality of samples, and transmit a digital message if the first adjustment percentage is greater than a first predetermined amount, and the second adjustment percentage is less than a second predetermined amount. a photosensitive circuit operable to generate a light intensity control signal in response to the total light intensity in the space; a wireless transmitter for transmitting wireless signals; a controller coupled to the photosensitive circuit and the wireless transmitter, the controller operable to transmit wireless signals in response to the light intensity control signal; and a battery for powering the photosensitive circuit, the wireless transmitter, and the controller, characterised in that; the controller is operable to sample the light intensity control signal to collect a first plurality of samples during a first time interval, and a second plurality of samples during a second, subsequent time interval, the first and second time intervals being non-overlapping, determine a minimum sample among the first plurality of samples, determine a minimum sample among the second plurality of samples; determine a maximum sample among the second plurality of samples, calculate a first adjustment percentage based on a difference between the minimum sample among the first plurality of samples and the minimum sample among the second plurality of samples, calculate a second adjustment percentage based on a difference between the minimum sample among the second plurality of samples and the maximum sample among the second plurality of samples, and transmit a digital message if the first adjustment percentage is greater than a first predetermined amount, and the second adjustment percentage is less than a second predetermined amount. sample the light intensity control signal to collect a first plurality of samples during a first time interval, and a second plurality of samples during a second, subsequent time interval, the first and second time intervals being non-overlapping, determine a minimum sample among the first plurality of samples, determine a minimum sample among the second plurality of samples; determine a maximum sample among the second plurality of samples, calculate a first adjustment percentage based on a difference between the minimum sample among the first plurality of samples and the minimum sample among the second plurality of samples, calculate a second adjustment percentage based on a difference between the minimum sample among the second plurality of samples and the maximum sample among the second plurality of samples, and transmit a digital message if the first adjustment percentage is greater than a first predetermined amount, and the second adjustment percentage is less than a second predetermined amount.