SAMDUE_PWM Library

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Table of Contents

• Why do we need this SAMDUE_PWM library
  • Features
  • Why using hardware-based PWM is better
  • Currently supported Boards
• Changelog
• Prerequisites
• Installation
  • Use Arduino Library Manager
  • Manual Install
  • VS Code & PlatformIO
• Usage
  • 1. Create PWM Instance with Pin, Frequency, dutycycle
  • 2. Initialize PWM Instance
  • 3. Set or change PWM frequency or dutyCycle
  • 4. Set or change PWM frequency and dutyCycle manually and efficiently in waveform creation
• Examples
  • 1. PWM_Basic
  • 2. PWM_DynamicDutyCycle
  • 3. PWM_DynamicDutyCycle_Int
  • 4. PWM_DynamicFreq
  • 5. PWM_Multi
  • 6. PWM_MultiChannel
  • 7. PWM_Waveform
  • 8. PWM_StepperControl New
• Example PWM_Multi
• Debug Terminal Output Samples
  • 1. PWM_DynamicDutyCycle using PWM on SAM_DUE
  • 2. PWM_Multi using Timer on SAM_DUE
  • 3. PWM_DynamicFreq using Timer on SAM_DUE
  • 4. PWM_Waveform using PWM on SAM_DUE
  • 5. PWM_Waveform using Timer on SAM_DUE
• Debug
• Troubleshooting
• Issues
• TO DO
• DONE
• Contributions and Thanks
• Contributing
• License
• Copyright

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Why do we need this SAMDUE_PWM library

Features

This hardware-based PWM library enables you to use Hardware-PWM on SAM_DUE boards to create and output PWM. These purely hardware-based PWM channels can generate very high PWM frequencies, depending on CPU clock and acceptable accuracy. The maximum resolution is only 8-bit resolution.

This library is based on analogWrite() function in wiring_analog.c of Arduino SAM_DUE core, to enable dynamic frequencies and dutycycles.

This library is using the same or similar functions as other FastPWM libraries, as follows, to enable you to port your PWM code easily between platforms

1. RP2040_PWM
2. AVR_PWM
3. megaAVR_PWM
4. ESP32_FastPWM
5. SAMD_PWM
6. SAMDUE_PWM
7. nRF52_PWM
8. Teensy_PWM
9. ATtiny_PWM
10. Dx_PWM
11. Portenta_H7_PWM
12. MBED_RP2040_PWM
13. nRF52_MBED_PWM
14. STM32_PWM

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The most important feature is they're purely hardware-based PWM channels. Therefore, their operations are not blocked by bad-behaving software functions / tasks.

This important feature is absolutely necessary for mission-critical tasks. These hardware PWM-channels, still work even if other software functions are blocking. Moreover, they are much more precise (certainly depending on clock frequency accuracy) than other software timers using millis() or micros(). That's necessary if you need to control external systems (Servo, etc.) requiring better accuracy.

New efficient setPWM_manual() function enables waveform creation using PWM.

The PWM_Multi example will demonstrate the usage of multichannel PWM using multiple Hardware-PWM blocks (Timer & Channel). The 4 independent Hardware-PWM channels are used to control 4 different PWM outputs, with totally independent frequencies and dutycycles on SAM_DUE.

Being hardware-based PWM, their executions are not blocked by bad-behaving functions / tasks, such as connecting to WiFi, Internet or Blynk services.

This non-being-blocked important feature is absolutely necessary for mission-critical tasks.

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Why using hardware-based PWM is better

Imagine you have a system with a mission-critical function, controlling a robot or doing something much more important. You normally use a software timer to poll, or even place the function in loop(). But what if another function is blocking the loop() or setup().

So your function might not be executed, and the result would be disastrous.

You'd prefer to have your function called, no matter what happening with other functions (busy loop, bug, etc.).

The correct choice is to use hardware-based PWM.

These hardware-based PWM channels still work even if other software functions are blocking. Moreover, they are much more precise (certainly depending on clock frequency accuracy) than other software-based PWMs, using millis() or micros().

Functions using normal software-based PWMs, relying on loop() and calling millis(), won't work if the loop() or setup() is blocked by certain operation. For example, certain function is blocking while it's connecting to WiFi or some services.

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Currently supported Boards

1. SAM_DUE boards, using Arduino SAM core

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Prerequisites

1. Arduino IDE 1.8.19+ for Arduino.
2. Arduino SAM core v1.6.12+

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Installation

Use Arduino Library Manager

The best and easiest way is to use Arduino Library Manager. Search for SAMDUE_PWM, then select / install the latest version. You can also use this link for more detailed instructions.

Manual Install

Another way to install is to:

1. Navigate to SAMDUE_PWM page.
2. Download the latest release SAMDUE_PWM-main.zip.
3. Extract the zip file to SAMDUE_PWM-main directory
4. Copy whole SAMDUE_PWM-main folder to Arduino libraries' directory such as ~/Arduino/libraries/.

VS Code & PlatformIO

1. Install VS Code
2. Install PlatformIO
3. Install SAMDUE_PWM library by using Library Manager. Search for SAMDUE_PWM in Platform.io Author's Libraries
4. Use included platformio.ini file from examples to ensure that all dependent libraries will installed automatically. Please visit documentation for the other options and examples at Project Configuration File

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Usage

Before using any PWM Timer and channel, you have to make sure the Timer and channel has not been used by any other purpose.

// SAM_DUE:
// PWM pins: 6, 7, 8, 9
// Timer pins: 2-5, 10-13. 
// pin2:   TC0_CHA0, pin3:  TC2_CHA7, pin4:  TC2_CHB6, pin5:  TC2_CHA6
// pin 10: TC2_CHB7, pin11: TC2_CHA8, pin12: TC2_CHB8, pin13: TC0_CHB0

1. Create PWM Instance with Pin, Frequency, dutycycle

SAMDUE_PWM* PWM_Instance;

PWM_Instance = new SAMDUE_PWM(pinToUse, frequency, dutyCycle, channel, PWM_resolution);

2. Initialize PWM Instance

if (PWM_Instance)
{
  PWM_Instance->setPWM();
}

3. Set or change PWM frequency or dutyCycle

To use float new_dutyCycle

PWM_Instance->setPWM(PWM_Pins, new_frequency, new_dutyCycle);

such as

dutyCycle = 10.0f;
  
Serial.print(F("Change PWM DutyCycle to ")); Serial.println(dutyCycle);
PWM_Instance->setPWM(pinToUse, frequency, dutyCycle);

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To use uint32_t new_dutyCycle = (real_dutyCycle * 65536) / 100

PWM_Instance->setPWM_Int(PWM_Pins, new_frequency, new_dutyCycle);

such as for real_dutyCycle = 50%

// 50% dutyCycle = (real_dutyCycle * 65536) / 100
dutyCycle = 32768;

Serial.print(F("Change PWM DutyCycle to (%) "));
Serial.println((float) dutyCycle * 100 / 65536);
PWM_Instance->setPWM_Int(pinToUse, frequency, dutyCycle);

for real_dutyCycle = 50%

// 20% dutyCycle = (real_dutyCycle * 65536) / 100
dutyCycle = 13107;

Serial.print(F("Change PWM DutyCycle to (%) "));
Serial.println((float) dutyCycle * 100 / 65536);
PWM_Instance->setPWM_Int(pinToUse, frequency, dutyCycle);

4. Set or change PWM frequency and dutyCycle manually and efficiently in waveform creation

Function prototype

bool setPWM_manual(const uint8_t& pin, const uint16_t& DCValue);

Need to call only once for each pin

PWM_Instance->setPWM(PWM_Pins, frequency, dutyCycle);

after that, if just changing dutyCycle / level, use

PWM_Instance->setPWM_manual(PWM_Pins, new_level);

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Examples:

1. PWM_Basic
2. PWM_DynamicDutyCycle
3. PWM_DynamicDutyCycle_Int
4. PWM_DynamicFreq
5. PWM_Multi
6. PWM_MultiChannel
7. PWM_Waveform
8. PWM_StepperControl New

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Example PWM_Multi

SAMDUE_PWM/examples/PWM_Multi/PWM_Multi.ino

Lines 11 to 117 in a5ac09f

	#define _PWM_LOGLEVEL_ 4
	// Can't use PWM for different frequencies
	#define USING_TIMER true
	#include "SAMDUE_PWM.h"
	// SAM_DUE:
	// PWM pins: 6, 7, 8, 9 ===> must be same frequency
	// Timer pins: 2-5, 10-13.
	// pin2: TC0_CHA0, pin3: TC2_CHA7, pin4: TC2_CHB6, pin5: TC2_CHA6
	// pin10: TC2_CHB7, pin11: TC2_CHA8, pin12: TC2_CHB8, pin13: TC0_CHB0
	#if USING_TIMER
	// To select correct pins for different frequencies
	uint32_t PWM_Pins[] = { 2, 3, 5, 11 };
	float frequency[] = { 2000.0f, 3000.0f, 4000.0f, 8000.0f };
	#else
	// always same frequency
	uint32_t PWM_Pins[] = { 6, 7, 8, 9 };
	float frequency[] = { 2000.0f, 2000.0f, 2000.0f, 2000.0f };
	#endif
	#define NUM_OF_PINS ( sizeof(PWM_Pins) / sizeof(uint32_t) )
	float dutyCycle[] = { 10.0f, 30.0f, 50.0f, 90.0f };
	SAMDUE_PWM* PWM_Instance[NUM_OF_PINS];
	char dashLine[] = "=====================================================================================";
	void printPWMInfo(SAMDUE_PWM* PWM_Instance)
	{
	Serial.println(dashLine);
	Serial.print("Actual data: pin = ");
	Serial.print(PWM_Instance->getPin());
	Serial.print(", PWM DC = ");
	Serial.print(PWM_Instance->getActualDutyCycle());
	Serial.print(", PWMPeriod = ");
	Serial.print(PWM_Instance->getPWMPeriod());
	Serial.print(", PWM Freq (Hz) = ");
	Serial.println(PWM_Instance->getActualFreq(), 4);
	Serial.println(dashLine);
	}
	void setup()
	{
	Serial.begin(115200);
	while (!Serial && millis() < 5000);
	delay(500);
	#if USING_TIMER
	Serial.print(F("\nStarting PWM_Multi using Timer on "));
	#else
	Serial.print(F("\nStarting PWM_Multi using PWM on "));
	#endif
	Serial.println(BOARD_NAME);
	Serial.println(SAMDUE_PWM_VERSION);
	for (uint8_t index = 0; index < NUM_OF_PINS; index++)
	{
	PWM_Instance[index] = new SAMDUE_PWM(PWM_Pins[index], frequency[index], dutyCycle[index]);
	if (PWM_Instance[index])
	{
	PWM_Instance[index]->setPWM();
	}
	}
	Serial.println(dashLine);
	Serial.println("Index\tPin\tPWM_freq\tDutyCycle\tActual Freq");
	Serial.println(dashLine);
	for (uint8_t index = 0; index < NUM_OF_PINS; index++)
	{
	if (PWM_Instance[index])
	{
	Serial.print(index);
	Serial.print("\t");
	Serial.print(PWM_Pins[index]);
	Serial.print("\t");
	Serial.print(frequency[index]);
	Serial.print("\t\t");
	Serial.print(dutyCycle[index]);
	Serial.print("\t\t");
	Serial.println(PWM_Instance[index]->getActualFreq(), 4);
	}
	else
	{
	Serial.println();
	}
	}
	for (uint8_t index = 0; index < NUM_OF_PINS; index++)
	{
	printPWMInfo(PWM_Instance[index]);
	}
	}
	void loop()
	{
	//Long delay has no effect on the operation of hardware-based PWM channels
	delay(1000000);
	}

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Debug Terminal Output Samples

1. PWM_DynamicDutyCycle using PWM on SAM_DUE

The following is the sample terminal output when running example PWM_DynamicDutyCycle on SAM_DUE, to demonstrate the ability to provide high PWM frequencies and ability to change DutyCycle on-the-fly using PWM

Starting PWM_DynamicDutyCycle using PWM on SAM_DUE
SAMDUE_PWM v1.0.1
[PWM] setupPWM: _pin = 6 , _pinAttr = 12 , frequency = 5000 , _dutycycle = 0
[PWM] setupPWM: Not PWMEnabled, PWMC_ConfigureClocks, frequency = 5000
[PWM] setupPWM: new _pin = 6 , _channel = 7
[PWM] setupPWM: _channel = 7 , _dutycycle = 0
=====================================================================================
Change PWM DutyCycle to 90.00
[PWM] setPWM: _dutycycle = 58982 , frequency = 5000.00
[PWM] setPWM_Int: dutycycle = 58982 , frequency = 5000.00
[PWM] setupPWM: _pin = 6 , _pinAttr = 12 , frequency = 5000 , _dutycycle = 58982
[PWM] setupPWM: _channel = 7 , _dutycycle = 58982
=====================================================================================
Actual data: pin = 6, PWM DC = 90.00, PWMPeriod = 200.00, PWM Freq (Hz) = 5000.0000
=====================================================================================
Change PWM DutyCycle to 20.00
[PWM] setPWM: _dutycycle = 13107 , frequency = 5000.00
[PWM] setPWM_Int: dutycycle = 13107 , frequency = 5000.00
[PWM] setupPWM: _pin = 6 , _pinAttr = 12 , frequency = 5000 , _dutycycle = 13107
[PWM] setupPWM: _channel = 7 , _dutycycle = 13107
=====================================================================================
Actual data: pin = 6, PWM DC = 20.00, PWMPeriod = 200.00, PWM Freq (Hz) = 5000.0000
=====================================================================================
Change PWM DutyCycle to 90.00
[PWM] setPWM: _dutycycle = 58982 , frequency = 5000.00
[PWM] setPWM_Int: dutycycle = 58982 , frequency = 5000.00
[PWM] setupPWM: _pin = 6 , _pinAttr = 12 , frequency = 5000 , _dutycycle = 58982
[PWM] setupPWM: _channel = 7 , _dutycycle = 58982
=====================================================================================
Actual data: pin = 6, PWM DC = 90.00, PWMPeriod = 200.00, PWM Freq (Hz) = 5000.0000
=====================================================================================
Change PWM DutyCycle to 20.00
[PWM] setPWM: _dutycycle = 13107 , frequency = 5000.00
[PWM] setPWM_Int: dutycycle = 13107 , frequency = 5000.00
[PWM] setupPWM: _pin = 6 , _pinAttr = 12 , frequency = 5000 , _dutycycle = 13107
[PWM] setupPWM: _channel = 7 , _dutycycle = 13107
=====================================================================================
Actual data: pin = 6, PWM DC = 20.00, PWMPeriod = 200.00, PWM Freq (Hz) = 5000.0000
=====================================================================================

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2. PWM_Multi using Timer on SAM_DUE

The following is the sample terminal output when running example PWM_Multi on SAM_DUE, to demonstrate the ability to provide high PWM frequencies on multiple PWM-capable pins using Timer for PWM

Starting PWM_Multi using Timer on SAM_DUE
SAMDUE_PWM v1.0.1
[PWM] setupPWM Timer: _pin = 2 , _pinAttr = 20 , frequency = 2000 , dutycycle = 2058
[PWM] setupPWM new Timer, frequency = 2000
[PWM] setupPWM Timer: _pin = 2 , _pinAttr = 20 , frequency = 2000 , dutycycle = 2058
[PWM] setupPWM Timer: _pin = 3 , _pinAttr = 20 , frequency = 3000 , dutycycle = 4172
[PWM] setupPWM new Timer, frequency = 3000
[PWM] setupPWM Timer: _pin = 3 , _pinAttr = 20 , frequency = 3000 , dutycycle = 4172
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 4000 , dutycycle = 5270
[PWM] setupPWM new Timer, frequency = 4000
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 4000 , dutycycle = 5270
[PWM] setupPWM Timer: _pin = 11 , _pinAttr = 20 , frequency = 8000 , dutycycle = 4735
[PWM] setupPWM new Timer, frequency = 8000
[PWM] setupPWM Timer: _pin = 11 , _pinAttr = 20 , frequency = 8000 , dutycycle = 4735
=====================================================================================
Index	Pin	PWM_freq	DutyCycle	Actual Freq
=====================================================================================
0	2	2000.00		10.00		2000.0000
1	3	3000.00		30.00		3000.0000
2	5	4000.00		50.00		4000.0000
3	11	8000.00		90.00		8000.0000
=====================================================================================
Actual data: pin = 2, PWM DC = 10.00, PWMPeriod = 500.00, PWM Freq (Hz) = 2000.0000
=====================================================================================
=====================================================================================
Actual data: pin = 3, PWM DC = 30.00, PWMPeriod = 333.33, PWM Freq (Hz) = 3000.0000
=====================================================================================
=====================================================================================
Actual data: pin = 5, PWM DC = 50.00, PWMPeriod = 250.00, PWM Freq (Hz) = 4000.0000
=====================================================================================
=====================================================================================
Actual data: pin = 11, PWM DC = 90.00, PWMPeriod = 125.00, PWM Freq (Hz) = 8000.0000
=====================================================================================

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3. PWM_DynamicFreq using Timer on SAM_DUE

The following is the sample terminal output when running example PWM_DynamicFreq on SAM_DUE, to demonstrate the ability to change dynamically PWM frequencies using Timer for PWM

Starting PWM_DynamicFreq using Timer on SAM_DUE
SAMDUE_PWM v1.0.1
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 10000 , dutycycle = 2108
[PWM] setupPWM new Timer, frequency = 10000
=====================================================================================
Change PWM Freq to 20000.00
[PWM] setPWM: _dutycycle = 32768 , frequency = 20000.00
[PWM] setPWM_Int: dutycycle = 32768 , frequency = 20000.00
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 20000 , dutycycle = 1054
[PWM] setupPWM: change frequency to 20000  from 10000.00
=====================================================================================
Actual data: pin = 5, PWM DC = 50.00, PWMPeriod = 50.00, PWM Freq (Hz) = 20000.0000
=====================================================================================
Change PWM Freq to 10000.00
[PWM] setPWM: _dutycycle = 32768 , frequency = 10000.00
[PWM] setPWM_Int: dutycycle = 32768 , frequency = 10000.00
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 10000 , dutycycle = 2108
[PWM] setupPWM: change frequency to 10000  from 20000.00
=====================================================================================
Actual data: pin = 5, PWM DC = 50.00, PWMPeriod = 100.00, PWM Freq (Hz) = 10000.0000
=====================================================================================
Change PWM Freq to 20000.00
[PWM] setPWM: _dutycycle = 32768 , frequency = 20000.00
[PWM] setPWM_Int: dutycycle = 32768 , frequency = 20000.00
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 20000 , dutycycle = 1054
[PWM] setupPWM: change frequency to 20000  from 10000.00
=====================================================================================
Actual data: pin = 5, PWM DC = 50.00, PWMPeriod = 50.00, PWM Freq (Hz) = 20000.0000
=====================================================================================

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4. PWM_Waveform using PWM on SAM_DUE

The following is the sample terminal output when running example PWM_Waveform on SAM_DUE, to demonstrate how to use the setPWM_manual() function in wafeform creation using PWM for PWM

Starting PWM_Waveform using PWM on SAM_DUE
SAMDUE_PWM v1.0.1
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 0
[PWM] setupPWM: Not PWMEnabled, PWMC_ConfigureClocks, frequency = 2000
[PWM] setupPWM: new _pin = 6 , _channel = 7
[PWM] setupPWM: _channel = 7 , _dutycycle = 0
[PWM] setPWM: _dutycycle = 0 , frequency = 2000.00
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 0
[PWM] setupPWM: _channel = 7 , _dutycycle = 0
============================================================================================
Actual data: pin = 6, PWM DutyCycle = 0.00, PWMPeriod = 500.00, PWM Freq (Hz) = 2000.0000
============================================================================================
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 0
[PWM] setupPWM: _channel = 7 , _dutycycle = 0
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 3276
[PWM] setupPWM: _channel = 7 , _dutycycle = 3276
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 6553
[PWM] setupPWM: _channel = 7 , _dutycycle = 6553
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 9830
[PWM] setupPWM: _channel = 7 , _dutycycle = 9830
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 13107
[PWM] setupPWM: _channel = 7 , _dutycycle = 13107
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 16383
[PWM] setupPWM: _channel = 7 , _dutycycle = 16383
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 19660
[PWM] setupPWM: _channel = 7 , _dutycycle = 19660
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 22937
[PWM] setupPWM: _channel = 7 , _dutycycle = 22937
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 26214
[PWM] setupPWM: _channel = 7 , _dutycycle = 26214
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 29490
[PWM] setupPWM: _channel = 7 , _dutycycle = 29490
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 32767
[PWM] setupPWM: _channel = 7 , _dutycycle = 32767
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 36044
[PWM] setupPWM: _channel = 7 , _dutycycle = 36044
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 39321
[PWM] setupPWM: _channel = 7 , _dutycycle = 39321
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 42597
[PWM] setupPWM: _channel = 7 , _dutycycle = 42597
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 45874
[PWM] setupPWM: _channel = 7 , _dutycycle = 45874
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 49151
[PWM] setupPWM: _channel = 7 , _dutycycle = 49151
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 52428
[PWM] setupPWM: _channel = 7 , _dutycycle = 52428
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 55704
[PWM] setupPWM: _channel = 7 , _dutycycle = 55704
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 58981
[PWM] setupPWM: _channel = 7 , _dutycycle = 58981
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 62258
[PWM] setupPWM: _channel = 7 , _dutycycle = 62258
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 65535
[PWM] setupPWM: _channel = 7 , _dutycycle = 65535
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 62258
[PWM] setupPWM: _channel = 7 , _dutycycle = 62258
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 58981
[PWM] setupPWM: _channel = 7 , _dutycycle = 58981
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 55704
[PWM] setupPWM: _channel = 7 , _dutycycle = 55704
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 52428
[PWM] setupPWM: _channel = 7 , _dutycycle = 52428
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 49151
[PWM] setupPWM: _channel = 7 , _dutycycle = 49151
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 45874
[PWM] setupPWM: _channel = 7 , _dutycycle = 45874
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 42597
[PWM] setupPWM: _channel = 7 , _dutycycle = 42597
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 39321
[PWM] setupPWM: _channel = 7 , _dutycycle = 39321
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 36044
[PWM] setupPWM: _channel = 7 , _dutycycle = 36044
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 32767
[PWM] setupPWM: _channel = 7 , _dutycycle = 32767
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 29490
[PWM] setupPWM: _channel = 7 , _dutycycle = 29490
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 26214
[PWM] setupPWM: _channel = 7 , _dutycycle = 26214
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 22937
[PWM] setupPWM: _channel = 7 , _dutycycle = 22937
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 19660
[PWM] setupPWM: _channel = 7 , _dutycycle = 19660
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 16383
[PWM] setupPWM: _channel = 7 , _dutycycle = 16383
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 13107
[PWM] setupPWM: _channel = 7 , _dutycycle = 13107
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 9830
[PWM] setupPWM: _channel = 7 , _dutycycle = 9830
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 6553
[PWM] setupPWM: _channel = 7 , _dutycycle = 6553
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 3276
[PWM] setupPWM: _channel = 7 , _dutycycle = 3276
[PWM] setupPWM: _pinAttr = 12 , frequency = 2000 , _dutycycle = 0
[PWM] setupPWM: _channel = 7 , _dutycycle = 0

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5. PWM_Waveform using Timer on SAM_DUE

The following is the sample terminal output when running example PWM_Waveform on SAM_DUE, to demonstrate how to use the setPWM_manual() function in wafeform creation using Timer for PWM

Starting PWM_Waveform using Timer on SAM_DUE
SAMDUE_PWM v1.0.1
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 0
[PWM] setupPWM new Timer, frequency = 2000
[PWM] setPWM: _dutycycle = 0 , frequency = 2000.00
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 0
============================================================================================
Actual data: pin = 5, PWM DutyCycle = 0.00, PWMPeriod = 500.00, PWM Freq (Hz) = 2000.0000
============================================================================================
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 0
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 988
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 2058
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 3129
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 4200
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 5188
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 6258
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 7329
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 8400
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 9470
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 10458
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 11529
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 12600
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 13670
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 14741
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 15729
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 16800
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 17870
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 18941
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 20011
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 21000
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 20011
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 18941
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 17870
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 16800
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 15729
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 14741
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 13670
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 12600
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 11529
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 10458
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 9470
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 8400
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 7329
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 6258
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 5188
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 4200
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 3129
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 2058
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 988
[PWM] setupPWM Timer: _pin = 5 , _pinAttr = 20 , frequency = 2000 , dutycycle = 0

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Debug

Debug is enabled by default on Serial.

You can also change the debugging level _PWM_LOGLEVEL_ from 0 to 4

// Don't define _PWM_LOGLEVEL_ > 0. Only for special ISR debugging only. Can hang the system.
#define _PWM_LOGLEVEL_     0

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Troubleshooting

If you get compilation errors, more often than not, you may need to install a newer version of the core for Arduino boards.

Sometimes, the library will only work if you update the board core to the latest version because I am using newly added functions.

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Issues

Submit issues to: SAMDUE_PWM issues

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TO DO

1. Search for bug and improvement.
2. Similar features for remaining Arduino boards

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DONE

1. Basic hardware PWM-channels for SAM_DUE boards using Arduino SAM core
2. Add example PWM_StepperControl to demo how to control Stepper Motor using PWM

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Contributions and Thanks

Many thanks for everyone for bug reporting, new feature suggesting, testing and contributing to the development of this library.

1. Thanks to Paul van Dinther for proposing new way to use PWM to drive Stepper-Motor in Using PWM to step a stepper driver #16, leading to v2.0.3

Paul van Dinther

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Contributing

If you want to contribute to this project:

• Report bugs and errors
• Ask for enhancements
• Create issues and pull requests
• Tell other people about this library

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License

• The library is licensed under MIT

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Copyright

Copyright (c) 2022- Khoi Hoang