Shows how to use the System.Device.Pwm API to use Pulse Width Modulation pins.
We will use a servo motor for this purpose. The schema is the following and pin 21 will be used. You can change the pin and adjust accordingly the pin:
And if you want to know more about PWM, how this works, you can read the All what you've always wanted to know about PWM content!
Ensure you have all the software requirements.
To build the sample, follow the section here. And to run it, here.
The sample is located here. The code is very straightforward with the explanations:
using System.Device.Pwm;
using System.Diagnostics;
using System.Threading;
using Iot.Device.ServoMotor;
using nanoFramework.Hardware.Esp32;
Debug.WriteLine("Hello from nanoFramework!");
// We are using pin 21, you can adjust the pin number based on the pin you are using
int pinServo = 21;
// When using an ESP32, you have to setup the pin function then create the PWM channel
Configuration.SetPinFunction(pinServo, DeviceFunction.PWM1);
// Each servo motor has specific pulse width limits, check the datasheet of the servo motor for the values
using PwmChannel pwmChannel = PwmChannel.CreateFromPin(pinServo, 50);
ServoMotor servoMotor = new ServoMotor(
pwmChannel,
180,
900,
2100);
servoMotor.Start(); // Enable control signal.
for (int i = 0; i < 10; i++)
{
// Move position.
// ~0.9ms; Approximately 0 degrees.
servoMotor.WriteAngle(0);
Thread.Sleep(1000);
// ~1.5ms; Approximately 90 degrees.
servoMotor.WriteAngle(90);
Thread.Sleep(1000);
// ~2.1ms; Approximately 180 degrees.
servoMotor.WriteAngle(180);
Thread.Sleep(1000);
}
servoMotor.Stop(); // Disable control signal.
Thread.Sleep(Timeout.Infinite);And as a result, you will see:
If you want to debug, follow the instructions explained in the led sample.