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Many (most?) household doorbell systems in the US are powered by a simple transformer that converts 120V AC household electric supply to a lower voltage AC. Often 16V AC or 24V AC. The coil and hammer form a device called a solenoid. When the coil is energized, the hammer (often also called a plunger) is forced in one direction, either up (against gravity) ...


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Expanding on my previous comment... I need a way to keep an array of memory ignored by the C initializer You can achieve this by instructing the compiler to store the array in the “.noinit” memory section: int my_array[ARRAY_LENGTH] __attribute__((section(".noinit"))); Your array will end up sitting somewhere between the .bss and the heap (if any), and ...


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You have a LiPo charger module. It's meant to charge single LiPo cells. It is therefore, the intended safe use that you can connect any single LiPo cell to it. All single cell LiPo batteries are nominally 3.7V. The only real question might be -- does the charging circuit try to charge too fast? A 2000mAh pouch LiPo can safely be charged at 1X the capacity. ...


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Much as I like Arduinos, it might be easier to just run a wire from your current doorbell to your office and add a 2nd doorbell, or a piezo buzzer that will run on AC. As others have said doorbells in the US are usually powered by AC, and that power is only available while the doorbell is actually ringing. You would need a constant source of power in order ...


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