eurorack/deprecated/midi2cv/drivers/encoder.cc

// Copyright 2013 Emilie Gillet.
//
// Author: Emilie Gillet (emilie.o.gillet@gmail.com)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
// See http://creativecommons.org/licenses/MIT/ for more information.
//
// -----------------------------------------------------------------------------
//
// Driver for rotary encoder.

#include "midi2cv/drivers/encoder.h"
#include "stm32f3xx_hal_gpio.h"

void Encoder::Init()
{
  __HAL_RCC_GPIOC_CLK_ENABLE();

  GPIO_InitTypeDef gpio_init;

  gpio_init.Pin = GPIO_PIN_13 | GPIO_PIN_14 | GPIO_PIN_15;
  gpio_init.Speed = GPIO_SPEED_FREQ_MEDIUM;
  gpio_init.Mode = GPIO_MODE_INPUT;
  gpio_init.Pull = GPIO_PULLUP;
  HAL_GPIO_Init(GPIOC, &gpio_init);

  switch_state_ = 0xff;
  quadrature_decoding_state_[0] = quadrature_decoding_state_[1] = 0xff;
}

void Encoder::Debounce()
{
  switch_state_ = (switch_state_ << 1) | HAL_GPIO_ReadPin(GPIOC, GPIO_PIN_15);
  quadrature_decoding_state_[0] = (quadrature_decoding_state_[0] << 1) | HAL_GPIO_ReadPin(GPIOC, GPIO_PIN_13);
  quadrature_decoding_state_[1] = (quadrature_decoding_state_[1] << 1) | HAL_GPIO_ReadPin(GPIOC, GPIO_PIN_14);
}