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Writes average PWM voltage to a GPIO pin

Add-On Required: This feature requires the MATLAB Support Package for Raspberry Pi Hardware add-on.


writePWMVoltage(mypi, pinNumber, voltage) writes the frequency of the output square wave to the output pin.

The PWM uses a software implementation allowing all GPIO pins on the Raspberry Pi® hardware board to output a PWM signal. Each PWM pin outputs a square waveform with variable frequency, duty cycle, or average voltage. A duty cycle of 0 means the waveform is always low and a duty cycle of 1 means the waveform is always high.

To use a PWM pin, reconfigure one of the multiple-use GPIO pins as a PWM pin.

Input Arguments

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Connection to the Raspberry Pi hardware board, specified as a raspi object.

GPIO pin number, specified as a scalar. This argument does not accept vectors because the hardware cannot access multiple pins simultaneously.

To get a list of valid pin numbers, enter mypi.AvailableDigitalPins.

Example: 12

Data Types: double

Mean voltage of the square wave at the output pin, in volts. The value is constrained between 0 V and 3.3 V. A value of 0 V produces no output. A value of 1.65 V produces a square wave with a 50% duty cycle at the output pin.


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Enable PWM pin 12 and set the frequency and duty cycle.

mypi = raspi();
configurePin(mypi, 12, 'PWM');
writePWMFrequency(mypi, 12, 2000);
writePWMVoltage(mypi, 12, 1.65);

The result is a square wave with a 50.0% duty cycle, frequency of 2000 hertz, and average voltage of 1.65 V.

Extended Capabilities

Version History

Introduced in R2016b