writePWMDutyCycle

Writes PWM duty cycle to PWM pin

Syntax

writePWMDutyCycle(mypi, pinNumber, dutyCycle)

Description

writePWMDutyCycle(mypi, pinNumber, dutyCycle) writes the duty cycle 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 operate as a PWM pin. 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 a specific 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

Duty cycle between 0 and 1 to assign to output pin.

Data Types: single | double

Examples

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

mypi = raspi();
configurePin(mypi, 12, 'PWM');
writePWMDutyCycle(mypi, 12, 0.5);
writePWMFrequency(mypi, 12, 2000);

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

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Introduced in R2016b