Home Alarm PCB Suite
Home alarms are one way of preventing crime that can lurk and enter the house. This alarm can provide sound according to the audio entered into the system. The following is an example of a series of home security alarms that utilize voice recorders using the ISD1420 IC.
The sound used in this alarm can be adjusted and can be played repeatedly so that it will make a loud noise and can wake the occupants of the house. The sound recorded can be fire alarms, police alarms and others coupled with our voice recordings for example with the word "Theft theft theft!".
In recording audio using an ISD1420 IC that can record audio for a duration of 20 seconds, while the other type ISD2560 can record for 1 minute. The sound captured by the microphone is then converted into an electric signal in the form of an analog audio signal, then by the ADC this signal is converted into digital, the digital signal is stored into eprom memory whose data will not be lost even if the power supply is turned off. Eventually this digital data was converted back into analog audio signals by the DAC and converted into sound by speakers. Memory space and recording mode can be accessed via Pin A0-A9.
In controlling this IC use the on off button that is already installed. To perform the recording, the Rec/Play and start buttons are pressed, to stop recording the removable start button. To play the recording we press the start button. There is a mode for automatic playback.
In this home alarm application, the triger of the circuit is a magnetic switch mounted on door sills and door leaves. When the door is closed then the switch will open, while when the door is opened by the thief then the switch will be closed and the alarm will be active so that it can make the thief panic and leave the house.
With the security system, this house is expected to eliminate the possibility of break-ins of homes or shops. To optimize the resulting sound can be connected to the audio to make the alert alarm sound even bigger.
