eurorack/stereo_mix/stereo_mix.cc

#include "drivers/adc.h"
#include "drivers/dac.h"
#include "drivers/peripherals.h"
#include "resources.h"
#include <stm32f0xx_hal.h>

using namespace stereo_mix;

Dac dacs[8] = {
  { GPIOB, GPIO_PIN_8 }, { GPIOB, GPIO_PIN_9 }, { GPIOB, GPIO_PIN_10 }, { GPIOB, GPIO_PIN_11 },
  { GPIOA, GPIO_PIN_8 }, { GPIOA, GPIO_PIN_9 }, { GPIOA, GPIO_PIN_10 }, { GPIOA, GPIO_PIN_11 }
};
Adc adc;

// Default interrupt handlers.
extern "C" {
void NMI_Handler() {}
void Error_Handler()
{
  while (1)
    ;
}
void HardFault_Handler()
{
  while (1)
    ;
}
void MemManage_Handler()
{
  while (1)
    ;
}
void BusFault_Handler()
{
  while (1)
    ;
}
void UsageFault_Handler()
{
  while (1)
    ;
}
void SVC_Handler() {}
void DebugMon_Handler() {}
void PendSV_Handler() {}

// called every 1ms
void SysTick_Handler()
{
  HAL_IncTick();
}

void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = { 0 };
  RCC_ClkInitTypeDef RCC_ClkInitStruct = { 0 };

  /** Initializes the CPU, AHB and APB busses clocks
   */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI14 | RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.HSI14State = RCC_HSI14_ON;
  RCC_OscInitStruct.HSI14CalibrationValue = 16;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL6;
  RCC_OscInitStruct.PLL.PREDIV = RCC_PREDIV_DIV1;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
    Error_Handler();
  }
  /** Initializes the CPU, AHB and APB busses clocks
   */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK
      | RCC_CLOCKTYPE_PCLK1;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK) {
    Error_Handler();
  }
}

void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)
{
  adc.OnDMATransferComplete();
}
}

int main(void)
{
  HAL_Init();
  SystemClock_Config();
  __HAL_RCC_SYSCFG_CLK_ENABLE();
  __HAL_RCC_PWR_CLK_ENABLE();

  while (true) {
    for (int i = 0; i < 4; i++) {
      uint32_t value_l;
      uint32_t value_r;

      uint16_t pan_pot = adc.value(ADC_GROUP_POT + ADC_CHANNEL_PAN_1 + i) >> (16 - 12); // adc is only 12 bit anyways
      uint16_t vol_pot = adc.value(ADC_GROUP_POT + ADC_CHANNEL_VOL_1 + i) >> (16 - 12);
      int16_t pan_cv = (adc.value(ADC_GROUP_CV + ADC_CHANNEL_PAN_1 + i) - 32768) >> (16 - 12);
      uint16_t vol_cv = adc.value(ADC_GROUP_CV + ADC_CHANNEL_VOL_1 + i) >> (16 - 12);
      int32_t pan = pan_pot + pan_cv;
      int32_t vol = vol_pot + vol_cv;

      CONSTRAIN(pan, 0, (1 << 12) - 1);
      CONSTRAIN(vol, 0, (1 << 12) - 1);

      value_l = (lut_left_sin_pan[pan] * lut_linear_to_exp[vol]) >> 16;
      value_r = (lut_right_cos_pan[pan] * lut_linear_to_exp[vol]) >> 16;

      dacs[i].Write16(0, value_r);
      dacs[i + 4].Write16(0, value_r);
      dacs[i].Write16(1, value_l);
      dacs[i + 4].Write16(1, value_l);
    }
  }
}