PWM

Pulse-Width Modulation (PWM) generates a square-wave signal of fixed frequency and variable duty cycle. It is commonly used to simulate an analog voltage, drive a servo, control LED brightness, and generate simple tones. Both the frequency and the duty cycle are set in software.

Endpoint uses the standard System.Device.Pwm API. The only Endpoint-specific step is calling PwmController.Initialize(pin) first, which claims the pin for its timer channel and gives you the chip and channel ids that PwmChannel.Create needs.

.NET

using System.Device.Pwm;
using GHIElectronics.Endpoint.Core;

// Buzzer pin on EP-Domino24
var pin = EPDomino24.Pwm.Pin.PF9;

PwmController.Initialize(pin);

using var pwm = PwmChannel.Create(
    PwmController.GetChipId(pin),
    PwmController.GetChannelId(pin),
    frequency: 1000,
    dutyCyclePercentage: 0.25);

pwm.Start();
Thread.Sleep(1000);
pwm.Stop();

Python

import time
from GHIElectronics.Endpoint.Core import EPDomino24, PwmController
from GHIElectronics.Endpoint.Devices.Pwm import PwmChannel

# Buzzer pin on EP-Domino24
pin = EPDomino24.Pwm.Pin.PF9

PwmController.Initialize(pin)

with PwmChannel.Create(PwmController.GetChipId(pin),
                      PwmController.GetChannelId(pin),
                      1000, 0.25) as pwm:
    pwm.Start()
    time.sleep(1)
    pwm.Stop()

C/C++

#include <chrono>
#include <thread>
#include <endpoint/PwmController.h>
#include <endpoint/EPDomino24.h>

using namespace GHIElectronics::Endpoint::Core;
using namespace GHIElectronics::Endpoint::Devices::Pwm;

// Buzzer pin on EP-Domino24
constexpr int pin = EPDomino24::Pwm::Pin::PF9;

PwmController::Initialize(pin);

auto pwm = PwmChannel::Create(PwmController::GetChipId(pin),
                              PwmController::GetChannelId(pin),
                              1000, 0.25);
pwm.Start();
std::this_thread::sleep_for(std::chrono::milliseconds(1000));
pwm.Stop();