home monitoring systems
, by connecting the wires 1014 1020. Then, the bypass unit 1012 generates the supply monitoring signal to indicate whether the input AC voltage is greater than the supply threshold, before the doorbell camera 106 needs to be connected to replace the conventional doorbell. Stated another way, if the supply monitoring signal indicates that the input AC voltage is not sufficient to drive the doorbell camera 106, a user does not need to take the efforts to replace the doorbell 1024 with the doorbell camera 106. Under some circumstances, the input AC voltage is substantially low and insufficient to support some camera functions that require relatively large power consumption. Optionally, the camera module 1004 is configured to in accordance with a determination that the input AC voltage is not greater than the supply threshold, disable capturing images and exchanging data with a remote server, and enable communication with a client device via a short range communication link e. g.