A PWM and servo library for ESP32 platform. This library follows the LEDC (LED Control) architecture from Espressif, see here.

The LEDC architecture requires a timer (for the frequency) and a channel (for the duty cycle). The combination of these are used in PWMController and the ServoController.

Typically, there are a (very) limited amount timers. This library therefore has several options for (automatic) timer sharing. This library has in itself no limits in the amount of PWM channels, Servo controllers, timers or channels. It scales based on the hardware capabilities.

Please see the UML in the documentation page.

Esp32LedcRegistry is a singleton used to register (/keep track of) the hardware platform capabilities. Each sketch using this library should start by letting Esp32LedcRegistry know the intended hardware platform using Esp32LedcRegistry::instance()->begin. PWMController and ServoController are the main classes to be used after this.

Depending on the platform (ESP32 subtype) used, timers and channels (as used by both PWMController and ServoController) might be of type 'high speed' and/or 'low speed'. Both PWMController and ServoController therefore require some guidance on which type should be used. PWMController.begin requires a Esp32LedcFactory instance. Options for that are:

• LowSpeedFactory: always creates timers and channels in the low speed variant, when available (read: not all used).
• HighSpeedFactory: always creates timers and channels in the high speed variant, when available for the platform and not fully used.
• BestAvailableFactory: tries to create high speed timers/channels first. When that is (no longer) an option, it will try the low speed variants.
• PwmFactoryDecorator: wraps one of the above Esp32LedcFactory instances, with the goal of sharing a timer with another PWMController if possible.

The easy option is therefor to use a PwmFactoryDecorator with a BestAvailableFactory in the case that there are no specific requirements. See PwmControllerShared in Examples.

For the ServoController.begin, a ServoFactoryDecorator is created. This ServoFactoryDecorator wraps a Esp32LedcFactory, making the interface easier to use. Servo specific settings (frequency, min. timing and max. timing) can all be globally set using Esp32LedcRegistry.

The main examples are:

• PwmController, which demonstrates a basic PWM setup.
• PwmControllerShared, which demonstrates a (library manager) timer-share.
• ServoController, demonstrating a basic servo setup. Please read the comments near setServoParams carefully. By default the Esp32LedcRegistry will use 1 - 2 msec for 0 to 180 degrees.

(the carefully hint to physical servo damage which might occur based on wrong timing. Please check the relevant datasheet)

In addition, there are two additional 'examples'. These are mainly used for my test purposes, 'test suite' is therefore a better description. These 'examples' might provide some additional clarification, but these are not really meant for that..

• PwmErrorHandlingTest_ESP32, is a test suite for a ESP32 setup (LilyGo T-Display)
• PwmErrorHandlingTest_ESP32_S3, is a test suite for a ESP32-S3 (LilyGo T-Display-S3)

I've compiled it for each ESP32 type found in the Esp32LedcRegistry comments, but have tested it only in the above two setup's.