Hacking an alarm clock

Posted on Feb 5, 2014

We will bypass the mechanical snooze switch on top, and instead turn the alarm clock off in a much more fun way: punching it! Hopefully along the way I will be able to teach you some techniques that are useful in reverse engineering, so you can apply them to future projects. This project is aimed at intermediate electronics enthusiasts, who have mastered the art of the multimeter and are comfortable

Hacking an alarm clock
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with soldering a complex circuit. This project involves working with a device that connects to mains voltages. The alarm clock I used just so happened to be designed so well that it was impossible to touch any mains voltages inside it. Other alarm clocks may not give you this comfort and will most likely have a different layout inside. Do not attempt this project unless you are 100% sure you know you can do it safely! The DE-ACCM is a good choice for this project because other vibration sensors such as mercury switches or reed switches only provide open or closed switch outputs, whereas the DE-ACCM provides a continuous analog voltage directly proportional to the intensity of the vibrations. For example, a mercury switch might prove to be too insensitive to measure the small vibrations of someone banging on the table, or it might be so sensitive that it activates simply from the vibration of the alarm clock`s speaker. With an accelerometer, you can easily design the circuit to trigger at any amount of vibration you want. We must find the ground and regulated positive voltage supply for the clock`s circuitry. We need this so we can power any additional circuits we design and insert into the clock. We must analyze the snooze button switch. When it opens/closes, what changes happen in the clock`s circuitry Knowing this information is necessary to design the circuit that will activate snooze. You can see four wires leading to...

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