custom_hal.ino

// JLed custom HAL example.
// Copyright 2019 by Jan Delgado. All rights reserved.
// https://github.com/jandelgado/jled

// we include jled_base.h instead of "jled.h" since we define our own JLed
// class using our custom HAL.
#include <jled_base.h>

// a custom HAL for the Arduino, inverting output and ticking with half
// the speed. In general, a JLed HAL class must satisfy the following
// interface:
//
// class JledHal {
//   public:
//     JledHal(PinType pin);
//     void analogWrite(uint8_t val) const;
//     uint32_t millis() const;
//  }
//
class CustomHal {
 public:
    using PinType = uint8_t;

    explicit CustomHal(PinType pin) noexcept : pin_(pin) {}

    void analogWrite(uint8_t val) const {
        // some platforms, e.g. STM need lazy initialization
        if (!setup_) {
            ::pinMode(pin_, OUTPUT);
            setup_ = true;
        }
        ::analogWrite(pin_, 255 - val);
    }

    uint32_t millis() const { return ::millis() >> 1; }

 private:
    mutable bool setup_ = false;
    PinType pin_;
};

class JLed : public jled::TJLed<CustomHal, JLed> {
    using jled::TJLed<CustomHal, JLed>::TJLed;
};

// uses above defined CustomHal
auto led = JLed(LED_BUILTIN).Blink(1000, 1000).Repeat(5);

void setup() {}

void loop() { led.Update(); }