DIGITAL INPUT

Digital input devices such as push switches can be connected to the PICAXE-08. The component layout is shown below. A 10k resistor is placed in series with the push switch or alternative digital input. Up to four digital inputs can be connected although this reduces the number of output devices that can be connected at the same time.

INPUT AND OUTPUT CIRCUITS

The circuit opposite shows how both input and output devices can be connected.
The example circuit is for an automatic animal feeder. When the animal pushes the switch the PICAXE microcontroller detects an input. The programme within the microcontroller then outputs at pin 6, energising a relay. This allows a second circuit to turn on a motor, releasing food into the animals dish.

QUESTION:
Draw a circuit diagram for a simple house alarm. The circuit must have at least one input. An output must activate a relay allowing a second circuit to turn on / off a buzzer.

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