User Manual

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When the button is pressed, the 4 pins are connected, thus closing the circuit.
Use a normally open button as the input of Raspberry Pi, the detailed connection is as shown
in the schematic diagram below . When the button is pressed, the B18 w ill turn into low level
(0V). We can detect the state of the B18 through programming. That is, if the B18 turns into
low lev el, it means the button is pressed. You can run the corresponding code when the
button is pressed, and then the LED will light up. Note: The longer pin of the LED is the anode
and the shorter one is the cathode.
Experimental Procedures
Step 1: Build the circuit
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