This example shows how to flash the on-board LED when you press a button that is connected to a GPIO pin.
Warning
Excessive voltage and current can damage the Raspberry Pi™ hardware. Observe the manufacturer’s precautions for handling the Raspberry Pi hardware and connecting it to other devices. For more information, see https://www.raspberrypi.org/technical-help-and-resource-documents.
Using a breadboard, set up the following circuit:
Connect one of the +3.3V pins on the GPIO header to a button.
Connect pin 23 on the GPIO header to a 220 or 330 Ohm resistor.
Connect the unconnected ends of the button and resistor to each other.
Note
Use showLEDs
to show an illustration that
identifies each pin.
Run the code and press the button. The button closes the circuit
between the +3.3V pin and pin 23. When readDigitalPin
detects
the raised voltage, if buttonPressed
becomes true
,
and writeLED
toggles the LED on and off ten times.
for ii = 1:100 buttonPressed = readDigitalPin(mypi,23) if buttonPressed for jj = 1:10 writeLED(mypi,'led0',1) pause(0.05) writeLED(mypi,'led0',0) pause(0.05) end end pause(0.1) end