Wireless battery-powered daylight sensor

A method of transmitting a digital message in response to a total light intensity in a space, the method comprising:

• measuring the total light intensity in the space;
• generating a light intensity control signal in response to the total light intensity in the space;
• periodically sampling the light intensity control signal;
• storing sampled light intensity values in memory;
• analyzing the sampled light intensity values stored in the memory to determine a rate of change of the total light intensity in the space;
• and
• transmitting digital messages using a variable transmission rate that is dependent upon an amount of change of the total light intensity in the space and the rate of change of the total light intensity in the space, each digital message including a value representative of the total light intensity.

A method of transmitting a digital message in response to a total light intensity in a space, the method comprising:

• measuring the total light intensity in the space;
• generating a light intensity control signal in response to the total light intensity in the space;
• determining a new light intensity for the lighting load in response to the light intensity control signal;
• and
• wirelessly transmitting digital messages if the new light intensity differs from a present light intensity of the lighting load by a predetermined increment, such that the digital messages are transmitted using a variable transmission rate that is dependent upon the total light intensity in the space, each digital message including a command to control a lighting load in response to the total light intensity.

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, the controller operable to periodically sample the light intensity control signal, the wireless signals comprising digital messages, each digital message including a value representative of the total light intensity;
• a memory coupled to the controller for storing sampled light intensity values;
• and
• a battery for powering the photosensitive circuit, the wireless transmitter, and the controller;
• wherein the controller is operable to analyze the samples stored in the memory to determine a rate of change of the total light intensity in the space, the controller operable to transmit the wireless signals using a variable transmission rate that is dependent upon the rate of change of the total light intensity in the space.

A load control system for controlling the power delivered from an AC power source to an electrical load located in a space of a building, the load control system comprising:

• a load control device coupled in series electrical connection between the source and the load for controlling the power delivered to the load;
• and
• a wireless battery-powered daylight sensor for measuring a light intensity in the space, the sensor operable to wirelessly transmit digital messages to the load control device in response to the light intensity control signal, each digital message including a value representative of the light intensity in the space, such that the load control device controls the power delivered to the load in response to the light intensity in the space, a controller operable to transmit the digital messages using a variable transmission rate that is dependent upon an amount of change of the light intensity in the space;
• wherein the controller does not transmit a digital message if a data is misbehaving.

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, the controller operable to transmit wireless signals using a variable transmission rate that is dependent upon the total light intensity in the space;
• and
• a battery for powering the photosensitive circuit, the wireless transmitter, and the controller;
• wherein the controller is operable to enable the photosensitive circuit and subsequently sample the light intensity control signal at a sampling period, the controller further operable to disable the photosensitive circuit after the light intensity control signal has been sampled, such that the photosensitive circuit only draws current from the battery for a small time period during each sampling period.

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, the controller operable to transmit wireless signals using a variable transmission rate that is dependent upon the total light intensity in the space;
• and
• a battery for powering the photosensitive circuit, the wireless transmitter, and the controller;
• wherein the controller is operable to disable the photosensitive circuit, such that the photosensitive circuit does not draw current from the battery when the wireless transmitter is not transmitting a wireless signal.

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 a wireless signal in response to the light intensity control signal;
• a battery for powering the photosensitive circuit, the wireless transmitter, and the controller;
• wherein the controller is operable to disable the photosensitive circuit, such that the photosensitive circuit does not draw current from the battery.

A wireless battery-powered daylight sensor for measuring a total light intensity in a space, the daylight sensor operates as part of a lighting control system that comprises a dimmer switch for controlling the amount of power delivered to a lighting load, 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 determine, in response to the light intensity control signal, a new light intensity to which the dimmer switch should control the intensity of the lighting load;
• a battery for powering the photosensitive circuit, the wireless transmitter, and the controller;
• wherein the controller is operable to enable the wireless transmitter and to transmit to the dimmer switch a wireless signal including a command that includes the new light intensity for the lighting load if the new light intensity differs from a present light intensity of the lighting load by a predetermined increment.

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 transceiver for transmitting and receiving wireless signals;
• a laser pointer circuit adapted to be exposed to light from a laser pointer;
• a controller coupled to the photosensitive circuit, the wireless transceiver, and the laser pointer circuit, the controller operable to transmit a wireless signal in response to the light intensity control signal;
• a battery for powering the photosensitive circuit, the wireless transceiver, and the controller;
• wherein the controller is operable to enable the wireless transceiver in response to light from a laser pointer shining on the laser pointer circuit, and to subsequently receive a wireless signal.

A load control system for controlling the power delivered from an AC power source to an electrical load located in a space of a building, the load control system comprising:

• a load control device coupled in series electrical connection between the source and the load for controlling the power delivered to the load;
• and
• a wireless battery-powered daylight sensor for measuring a light intensity in the space, the sensor operable to wirelessly transmit digital messages to the load control device in response to the light intensity control signal, each digital message including a value representative of the light intensity in the space, such that the load control device controls the power delivered to the load in response to the light intensity in the space, a controller operable to transmit the digital messages using a variable transmission rate that is dependent upon an amount of change of the light intensity in the space and a rate of change of the light intensity in the space;
• wherein the controller transmits a digital message if the rate of change of the total light intensity is within predetermined limits.

A load control system for controlling the power delivered from an AC power source to an electrical load located in a space of a building, the load control system comprising:

• a load control device coupled in series electrical connection between the source and the load for controlling the power delivered to the load;
• and
• a wireless battery-powered daylight sensor for measuring a light intensity in the space, the sensor operable to wirelessly transmit digital messages to the load control device in response to the light intensity control signal, each digital message including a value representative of the light intensity in the space, such that the load control device controls the power delivered to the load in response to the light intensity in the space, a controller operable to transmit the digital messages using a variable transmission rate that is dependent upon an amount of change of the light intensity in the space;
• wherein the daylight sensor only transmits a digital message to the load control device if the light intensity in the space has changed by a predetermined amount.

A load control system for controlling the power delivered from an AC power source to a lighting load located in a space of a building, the load control system comprising:

• a dimmer switch coupled in series electrical connection between the source and the lighting load for controlling the power delivered to the lighting load;
• and
• a wireless battery-powered daylight sensor for measuring a light intensity in the space, the sensor operable to wirelessly transmit digital messages to the dimmer switch in response to the light intensity control signal, each digital message including a value representative of the light intensity in the space, such that the dimmer switch controls the power delivered to the lighting load in response to the light intensity in the space, a controller operable to transmit the digital messages using a variable transmission rate that is dependent upon the light intensity in the space;
• A wherein the daylight sensor is operable to determine a new light intensity for the lighting load in response to the light intensity in the space, the daylight sensor operable to transmit a digital signal to the dimmer switch if the new light intensity differs from a present light intensity of the lighting load by a predetermined increment.

A method of transmitting a digital message in response to a total light intensity in a space, the method comprising:

• measuring the total light intensity in the space;
• generating a light intensity control signal in response to the total light intensity in the space;
• periodically sampling the light intensity control signal;
• storing sampled light intensity values in memory;
• analyzing the sampled light intensity values stored in the memory to determine an amount of change of the total light intensity in the space;
• and by a controller
• transmitting digital messages by a controller using a variable transmission rate that is dependent upon the amount of change of the total light intensity in the space, each digital message including a value representative of the total light intensity.