An orientation detection circuit is provided. The circuit includes a processor, a first resistor, a second resistor, a third resistor, a vibration switch, a first transistor, and a second transistor. The processor includes a first input pin and a second input pin. The third resistor has a resistance value greater than that of the first resistor and the third resistor. The vibration switch includes a first terminal being grounded, a second terminal connected to the second input pin, a third terminal connected to a power source, and a fourth terminal connected via the third resistor to the second terminal and connected to the first input pin. The first transistor has a first source connected via the first resistor to the power source, a first drain connected to the first input pin, and a first gate connected to the second input pin.