# Enhanced Servo Library for ESP32

Compatible with Arduino ESP32 v3.0.0+ with advanced PWM hardware support.

https://github.com/espressif/arduino-esp32/releases

This library provides enhanced PWM control for ESP32 boards, faithfully replicating Arduino Servo semantics while adding advanced hardware support:

## Key Features

- **ESP32S3 MCPWM Support**: Hardware-accelerated servo control for optimal timing precision
- **Dual Hardware Architecture**: 20 PWM channels (8 LEDC + 12 MCPWM) with intelligent allocation
- **Flexible Frequency Modes**: Variable-frequency PWM and fixed-frequency servo control
- **Automatic Fallback**: Seamless hardware allocation when preferred resources are unavailable
- **Backward Compatible**: Drop-in replacement for existing Arduino Servo code

## Hardware Support

| ESP32 Variant | LEDC Channels | MCPWM Channels | Total Channels |
|---------------|---------------|----------------|----------------|
| ESP32S3       | 8             | 12             | 20             |
| ESP32S2       | 8             | -              | 8              |
| ESP32         | 16            | -              | 16             |
| ESP32C3       | 6             | -              | 6              |

## Usage Examples

### Basic Servo Control
```cpp
#include <ESP32Servo.h>

Servo myservo;
myservo.attach(18);        // Attach to pin 18
myservo.write(90);         // Set to 90 degrees
```

### Advanced PWM Control
```cpp
#include <ESP32PWM.h>

// Variable frequency (default) - LEDC preferred
ESP32PWM pwm1;             // or ESP32PWM pwm1(true);

// Fixed frequency - MCPWM preferred
ESP32PWM pwm2(false);      // Optimal for servos

pwm1.attachPin(19, 1000, 10);  // 1kHz, 10-bit resolution
pwm2.attachPin(21, 50, 10);    // 50Hz, 10-bit resolution
```
# Documentation by Doxygen

[ESP32Servo Doxygen](https://madhephaestus.github.io/ESP32Servo/annotated.html)

## License

Copyright (c) 2017 John K. Bennett.  All right reserved.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

## Library Description:
```
    Servo - Class for manipulating servo motors connected to ESP32 pins.
    
    int attach(pin )  - Attaches the given GPIO pin to the next free channel
        (channels that have previously been detached are used first), 
        returns channel number or 0 if failure. All pin numbers are allowed,
        but only pins 2,4,12-19,21-23,25-27,32-33 are recommended.
    
    int attach(pin, min, max  ) - Attaches to a pin setting min and max 
        values in microseconds; enforced minimum min is 500, enforced max
        is 2500. Other semantics are the same as attach().
    
    void write () - Sets the servo angle in degrees; a value below 500 is
        treated as a value in degrees (0 to 180). These limit are enforced,
        i.e., values are constrained as follows:
            Value                                   Becomes
            -----                                   -------
            < 0                                        0
            0 - 180                                  value (treated as degrees)
            181 - 499                                 180
            500 - (min-1)                             min
            min-max (from attach or default)         value (treated as microseconds)
            (max+1) - 2500                            max
    
    void writeMicroseconds() - Sets the servo pulse width in microseconds.
        min and max are enforced (see above). 
        
    int read() - Gets the last written servo pulse width as an angle between 0 and 180. 
    
    int readMicroseconds()   - Gets the last written servo pulse width in microseconds.
    
    bool attached() - Returns true if this servo instance is attached to a pin.
    
    void detach() - Stops an the attached servo, frees the attached pin, and frees
        its channel for reuse.  
```

### **New ESP32-specific functions**
 
```
    setTimerWidth(value) - Sets the PWM timer width (must be 16-20) (ESP32 ONLY);
        as a side effect, the pulse width is recomputed.

    int readTimerWidth() - Gets the PWM timer width (ESP32 ONLY) 
```
 
### Useful Defaults:

default min pulse width for attach(): 544us

default max pulse width for attach(): 2400us

default timer width 16 (if timer width is not set)

default pulse width 1500us (servos are initialized with this value)

MINIMUM pulse with: 500us

MAXIMUM pulse with: 2500us

MAXIMUM number of servos: Varies by ESP32 variant
- ESP32S3: 20 channels (8 LEDC + 12 MCPWM)
- ESP32: 16 channels (16 LEDC)
- ESP32S2: 8 channels (8 LEDC)
- ESP32C3: 6 channels (6 LEDC)
