v1.0.0 for hardware-PWM on ESP32 boards

### Releases v1.0.0

1. Initial coding for ESP32, ESP32_S2, ESP32_S3 and ESP32_C3 boards using [ESP32 core](https://github.com/espressif/arduino-esp32)

CONTRIBUTING.md

@@ -0,0 +1,81 @@
+## Contributing to ESP32_FastPWM
+
+### Reporting Bugs
+
+Please report bugs in [ESP32_FastPWM Issues](https://github.com/khoih-prog/ESP32_FastPWM/issues) if you find them.
+
+However, before reporting a bug please check through the following:
+
+* [Existing Open Issues](https://github.com/khoih-prog/ESP32_FastPWM/issues) - someone might have already encountered this.
+
+If you don't find anything, please [open a new issue](https://github.com/khoih-prog/ESP32_FastPWM/issues/new).
+
+### How to submit a bug report
+
+Please ensure to specify the following:
+
+* Arduino IDE version (e.g. 1.8.19) or Platform.io version
+* `ESP32` Core Version (e.g. ESP32 core v2.0.5)
+* `ESP32` Board type (e.g. ESP32_DEV Module, etc.)
+* `ESP32-S2` Board type (e.g. ESP32S2_DEV Module, ESP32_S2_Saola, etc.)
+* `ESP32_S3` Board type (e.g. ESP32S3_DEV, ESP32_S3_BOX, UM TINYS3, UM PROS3, UM FEATHERS3, etc.)
+* `ESP32-C3` Board type (e.g. ESP32C3_DEV Module, etc.)
+* Contextual information (e.g. what you were trying to achieve)
+* Simplest possible steps to reproduce
+* Anything that might be relevant in your opinion, such as:
+  * Operating system (Windows, Ubuntu, etc.) and the output of `uname -a`
+  * Network configuration
+
+
+### Example
+
+```
+Arduino IDE version: 1.8.19
+ESP32 core v2.0.5
+ESP32S3_DEV Module
+OS: Ubuntu 20.04 LTS
+Linux xy-Inspiron-3593 5.15.0-52-generic #58~20.04.1-Ubuntu SMP Thu Oct 13 13:09:46 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
+
+Context:
+I encountered a crash while using TimerInterrupt.
+
+Steps to reproduce:
+1. ...
+2. ...
+3. ...
+4. ...
+```
+
+### Additional context
+
+Add any other context about the problem here.
+
+---
+
+### Sending Feature Requests
+
+Feel free to post feature requests. It's helpful if you can explain exactly why the feature would be useful.
+
+There are usually some outstanding feature requests in the [existing issues list](https://github.com/khoih-prog/ESP32_FastPWM/issues?q=is%3Aopen+is%3Aissue+label%3Aenhancement), feel free to add comments to them.
+
+---
+
+### Sending Pull Requests
+
+Pull Requests with changes and fixes are also welcome!
+
+Please use the `astyle` to reformat the updated library code as follows (demo for Ubuntu Linux)
+
+1. Change directory to the library GitHub
+
+```
+xy@xy-Inspiron-3593:~$ cd Arduino/xy/ESP32_FastPWM_GitHub/
+xy@xy-Inspiron-3593:~/Arduino/xy/ESP32_FastPWM_GitHub$
+```
+
+2. Issue astyle command
+
+```
+xy@xy-Inspiron-3593:~/Arduino/xy/ESP32_FastPWM_GitHub$ bash utils/restyle.sh
+```
+

changelog.md

@@ -0,0 +1,25 @@
+# ESP32_FastPWM Library
+
+[![arduino-library-badge](https://www.ardu-badge.com/badge/ESP32_FastPWM.svg?)](https://www.ardu-badge.com/ESP32_FastPWM)
+[![GitHub release](https://img.shields.io/github/release/khoih-prog/ESP32_FastPWM.svg)](https://github.com/khoih-prog/ESP32_FastPWM/releases)
+[![GitHub](https://img.shields.io/github/license/mashape/apistatus.svg)](https://github.com/khoih-prog/ESP32_FastPWM/blob/master/LICENSE)
+[![contributions welcome](https://img.shields.io/badge/contributions-welcome-brightgreen.svg?style=flat)](#Contributing)
+[![GitHub issues](https://img.shields.io/github/issues/khoih-prog/ESP32_FastPWM.svg)](http://github.com/khoih-prog/ESP32_FastPWM/issues)
+
+---
+---
+
+## Table of Contents
+
+* [Changelog](#changelog)
+  * [Releases v1.0.0](#releases-v100)
+
+---
+---
+
+## Changelog
+
+
+### Releases v1.0.0
+
+1. Initial coding for ESP32, ESP32_S2, ESP32_S3 and ESP32_C3 boards using [ESP32 core](https://github.com/espressif/arduino-esp32)

examples/PWM_Basic/PWM_Basic.ino

@@ -0,0 +1,74 @@
+/****************************************************************************************************************************
+  PWM_Basic.ino
+
+  For ESP32, ESP32_S2, ESP32_S3, ESP32_C3 boards with ESP32 core v2.0.0+
+  Written by Khoi Hoang
+
+  Built by Khoi Hoang https://github.com/khoih-prog/ESP32_FastPWM
+  Licensed under MIT license
+
+  This is pure hardware-based PWM
+*****************************************************************************************************************************/
+/******************************************************************************************************************************
+// All GPIO pins (but GPIO34-39) can be used to generate PWM
+// For ESP32, number of channels is 16, max 20-bit resolution
+// For ESP32_S2, ESP32_S3, number of channels is 8
+// For ESP32_C3, number of channels is 6
+******************************************************************************************************************************/
+
+#define _PWM_LOGLEVEL_       4
+
+#include "ESP32_FastPWM.h"
+
+#if ARDUINO_ESP32C3_DEV
+  #define pinToUse       9
+#else
+  #define pinToUse       16
+#endif
+
+// Max resolution is 20-bit
+// Resolution 65536 (16-bit) for lower frequencies, OK @ 1K
+// Resolution  4096 (12-bit) for lower frequencies, OK @ 10K
+// Resolution  1024 (10-bit) for higher frequencies, OK @ 50K
+// Resolution  256  ( 8-bit)for higher frequencies, OK @ 100K, 200K
+// Resolution  128  ( 7-bit) for higher frequencies, OK @ 500K
+int PWM_resolution       = 12;
+
+//creates pwm instance
+ESP32_FAST_PWM* PWM_Instance;
+
+float frequency = 1000.0f;
+float dutyCycle = 0.0f;
+
+uint8_t channel = 0;
+
+void setup()
+{
+  Serial.begin(115200);
+
+  while (!Serial && millis() < 5000);
+
+  delay(500);
+
+  Serial.print(F("\nStarting PWM_Basic on "));
+  Serial.println(ARDUINO_BOARD);
+  Serial.println(ESP32_FAST_PWM_VERSION);
+
+  //assigns PWM frequency of 1.0 KHz and a duty cycle of 0%, channel 0, 12-bit resolution
+  PWM_Instance = new ESP32_FAST_PWM(pinToUse, frequency, dutyCycle, channel, PWM_resolution);
+}
+
+void loop()
+{
+  frequency = 2000.0f;
+  dutyCycle = 20.0f;
+
+  PWM_Instance->setPWM(pinToUse, frequency, dutyCycle);
+
+  delay(5000);
+  dutyCycle = 90.0f;
+
+  PWM_Instance->setPWM(pinToUse, frequency, dutyCycle);
+
+  delay(5000);
+}

examples/PWM_DynamicDutyCycle/PWM_DynamicDutyCycle.ino

@@ -0,0 +1,109 @@
+/****************************************************************************************************************************
+  PWM_DynamicDutyCycle.ino
+
+  For ESP32, ESP32_S2, ESP32_S3, ESP32_C3 boards with ESP32 core v2.0.0+
+  Written by Khoi Hoang
+
+  Built by Khoi Hoang https://github.com/khoih-prog/ESP32_FastPWM
+  Licensed under MIT license
+
+  This is pure hardware-based PWM
+*****************************************************************************************************************************/
+/******************************************************************************************************************************
+  // All GPIO pins (but GPIO34-39) can be used to generate PWM
+  // For ESP32, number of channels is 16, max 20-bit resolution
+  // For ESP32_S2, ESP32_S3, number of channels is 8
+  // For ESP32_C3, number of channels is 6
+******************************************************************************************************************************/
+
+#define _PWM_LOGLEVEL_       4
+
+#include "ESP32_FastPWM.h"
+
+#if ARDUINO_ESP32C3_DEV
+  #define pinToUse       9
+#else
+  #define pinToUse       16
+#endif
+
+// Max resolution is 20-bit
+// Resolution 65536 (16-bit) for lower frequencies, OK @ 1K
+// Resolution  4096 (12-bit) for lower frequencies, OK @ 10K
+// Resolution  1024 (10-bit) for higher frequencies, OK @ 50K
+// Resolution  256  ( 8-bit)for higher frequencies, OK @ 100K, 200K
+// Resolution  128  ( 7-bit) for higher frequencies, OK @ 500K
+int PWM_resolution       = 12;
+
+//creates pwm instance
+ESP32_FAST_PWM* PWM_Instance;
+
+float frequency;
+float dutyCycle;
+
+char dashLine[] = "=====================================================================================";
+
+void printPWMInfo(ESP32_FAST_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);
+
+  Serial.print(F("\nStarting PWM_DynamicDutyCycle on "));
+  Serial.println(ARDUINO_BOARD);
+  Serial.println(ESP32_FAST_PWM_VERSION);
+
+  frequency = 5000.0f;
+
+  PWM_Instance = new ESP32_FAST_PWM(pinToUse, frequency, 50.0f);
+
+  if (PWM_Instance)
+  {
+    if (!PWM_Instance->setPWM())
+    {
+      Serial.println(F("Stop here"));
+
+      // stop here
+      while (true)
+        delay(1000);
+    }
+  }
+
+  Serial.println(dashLine);
+}
+
+void loop()
+{
+  dutyCycle = 90.0f;
+
+  Serial.print(F("Change PWM DutyCycle to "));
+  Serial.println(dutyCycle);
+  PWM_Instance->setPWM(pinToUse, frequency, dutyCycle);
+
+  printPWMInfo(PWM_Instance);
+
+  delay(5000);
+  dutyCycle = 20.0f;
+
+  Serial.print(F("Change PWM DutyCycle to "));
+  Serial.println(dutyCycle);
+  PWM_Instance->setPWM(pinToUse, frequency, dutyCycle);
+  printPWMInfo(PWM_Instance);
+
+  delay(5000);
+}