Devices, methods, and systems for a self-testing fire sensing device are described herein. One device includes an adjustable particle generator and a variable airflow generator configured to generate an aerosol density level, an optical scatter chamber configured to measure a rate at which the aerosol density level decreases after the aerosol density level has been generated, and a controller configured to compare the measured rate at which the aerosol density level decreases with a baseline rate, and determine whether the self-testing fire sensing device requires maintenance based on the comparison of the measured rate at which the aerosol density level decreases and the baseline rate.

Devices, methods, and systems for a self-testing fire sensing device are described herein. One device includes an adjustable particle generator and a variable airflow generator configured to generate an aerosol density level, an optical scatter chamber configured to measure a rate at which the aerosol density level decreases after the aerosol density level has been generated, and a controller configured to compare the measured rate at which the aerosol density level decreases with a baseline rate, and determine whether the self-testing fire sensing device requires maintenance based on the comparison of the measured rate at which the aerosol density level decreases and the baseline rate.

Methods and systems including computer programs encoded on a computer storage medium, for receiving, for a multi-tenant dwelling unit (MDU), a map of the MDU, where the map includes locations corresponding to multiple sensors at the MDU and defines multiple sub-areas of the MDU, receiving sensor data from one or more sensors of the plurality of sensors, where the sensor data is indicative of a fire event at the MDU, determining, from the sensor data, one or more sub-areas of the multiple sub-areas included in the fire event, generating, based on the sensor data, a targeted fire event response for the one or more sub-areas of the multiple sub-areas of the MDU, and providing, to the one or more sub-areas of the multiple sub-areas, the targeted fire event response.

A cover to temporarily deactivate a smoke detector. The cover is placed over a smoke detector to temporarily prevent smoke detection and removed when the smoke producing activity has been completed.

A cover to temporarily deactivate a smoke detector. The cover is placed over a smoke detector to temporarily prevent smoke detection and removed when the smoke producing activity has been completed.

Systems and methods for using multi-criteria state machines to manage alarming states and pre-alarming states of a hazard detection system are described herein. The multi-criteria state machines can include one or more sensor state machines that can control the alarming states and one or more system state machines that can control the pre-alarming states. Each state machine can transition among any one of its states based on sensor data values, hush events, and transition conditions. The transition conditions can define how a state machine transitions from one state to another. The hazard detection system can use a dual processor arrangement to execute the multi-criteria state machines according to various embodiments. The dual processor arrangement can enable the hazard detection system to manage the alarming and pre-alarming states in a manner that promotes minimal power usage while simultaneously promoting reliability in hazard detection and alarming functionality.

Systems and methods for using multi-criteria state machines to manage alarming states and pre-alarming states of a hazard detection system are described herein. The multi-criteria state machines can include one or more sensor state machines that can control the alarming states and one or more system state machines that can control the pre-alarming states. Each state machine can transition among any one of its states based on sensor data values, hush events, and transition conditions. The transition conditions can define how a state machine transitions from one state to another. The hazard detection system can use a dual processor arrangement to execute the multi-criteria state machines according to various embodiments. The dual processor arrangement can enable the hazard detection system to manage the alarming and pre-alarming states in a manner that promotes minimal power usage while simultaneously promoting reliability in hazard detection and alarming functionality.

According to one embodiment, a multi-sensing hazard detector for detecting potential dangers may include a back plate and a front casing that is coupled with the back plate to define a housing. A circuit board and a plurality of components may be positioned within the housing. The circuit board may be communicatively coupled with the components. The components may include, among other components, an alarm device, an occupancy sensor, and a smoke chamber. The alarm device may be activatable upon the detection of a potential hazard to warn an occupant of a potential danger, the occupancy sensor may be configured to detect the presence and/or movement of objects external to the hazard detector, and the smoke chamber may be configured to detect the presence of smoke to cause a triggering of the alarm device. The housing may comprise a volume of less than 1024 cubic centimeters.

According to one embodiment, a multi-sensing hazard detector for detecting potential dangers may include a back plate and a front casing that is coupled with the back plate to define a housing. A circuit board and a plurality of components may be positioned within the housing. The circuit board may be communicatively coupled with the components. The components may include, among other components, an alarm device, an occupancy sensor, and a smoke chamber. The alarm device may be activatable upon the detection of a potential hazard to warn an occupant of a potential danger, the occupancy sensor may be configured to detect the presence and/or movement of objects external to the hazard detector, and the smoke chamber may be configured to detect the presence of smoke to cause a triggering of the alarm device. The housing may comprise a volume of less than 1024 cubic centimeters.

This application is directed to a home monitoring and control system including a doorbell installed at a door of a home. The doorbell has a button configured to, upon being touched, depressed or activated, wirelessly initiate a first communication to indicate presence of a person at the door. The doorbell also has a camera configured to capture video data within a field of view, and a processor configured to cause a communication component to enable the first communication and wirelessly stream via a remote server the video data captured by the camera to a monitoring device associated with an occupant of the home. A rechargeable battery is coupled to a housing wire and configured to be charged via the housing wire, and the doorbell is configured to charge and discharge the rechargeable battery based on power usage of the doorbell.