hoverboard-firmware-hack-foc-serial-esc/Src/main.c

/*
* This file is part of the hoverboard-firmware-hack project.
*
* Copyright (C) 2017-2018 Rene Hopf <renehopf@mac.com>
* Copyright (C) 2017-2018 Nico Stute <crinq@crinq.de>
* Copyright (C) 2017-2018 Niklas Fauth <niklas.fauth@kit.fail>
* Copyright (C) 2019-2020 Emanuel FERU <aerdronix@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <stdlib.h> // for abs()
#include "stm32f1xx_hal.h"
#include "defines.h"
#include "setup.h"
#include "config.h"
#include "comms.h"

#if defined(DEBUG_I2C_LCD) || defined(SUPPORT_LCD)
  #include "hd44780.h"
#endif

#ifdef VARIANT_TRANSPOTTER
  #include "eeprom.h"
#endif

// Matlab includes and defines - from auto-code generation
// ###############################################################################
#include "BLDC_controller.h"      /* Model's header file */
#include "rtwtypes.h"

RT_MODEL rtM_Left_;               /* Real-time model */
RT_MODEL rtM_Right_;              /* Real-time model */
RT_MODEL *const rtM_Left    = &rtM_Left_;
RT_MODEL *const rtM_Right   = &rtM_Right_;

P     rtP_Left;                   /* Block parameters (auto storage) */
DW    rtDW_Left;                  /* Observable states */
ExtU  rtU_Left;                   /* External inputs */
ExtY  rtY_Left;                   /* External outputs */

P     rtP_Right;                  /* Block parameters (auto storage) */
DW    rtDW_Right;                 /* Observable states */
ExtU  rtU_Right;                  /* External inputs */
ExtY  rtY_Right;                  /* External outputs */

extern uint8_t errCode_Left;      /* Global variable to handle Motor error codes */
extern uint8_t errCode_Right;     /* Global variable to handle Motor error codes */
// ###############################################################################

void SystemClock_Config(void);
void poweroff(void);

extern TIM_HandleTypeDef htim_left;
extern TIM_HandleTypeDef htim_right;
extern ADC_HandleTypeDef hadc1;
extern ADC_HandleTypeDef hadc2;
extern volatile adc_buf_t adc_buffer;
#if defined(DEBUG_I2C_LCD) || defined(SUPPORT_LCD)
  LCD_PCF8574_HandleTypeDef lcd;
#endif
extern I2C_HandleTypeDef hi2c2;
#if defined(CONTROL_SERIAL_USART2) || defined(FEEDBACK_SERIAL_USART2) || defined(DEBUG_SERIAL_USART2) \
 || defined(CONTROL_SERIAL_USART3) || defined(FEEDBACK_SERIAL_USART3) || defined(DEBUG_SERIAL_USART3) 
  extern UART_HandleTypeDef huart2;
  extern UART_HandleTypeDef huart3;
  static UART_HandleTypeDef huart;
#endif

#if defined(DEBUG_I2C_LCD) || defined(SUPPORT_LCD)
  extern uint8_t LCDerrorFlag;
#endif

#ifdef VARIANT_TRANSPOTTER
  uint8_t nunchuk_connected = 0;
  float steering;
  int feedforward;

  void saveConfig(void);

  /* Virtual address defined by the user: 0xFFFF value is prohibited */
  uint16_t VirtAddVarTab[NB_OF_VAR] = {0x1337};
  uint16_t VarDataTab[NB_OF_VAR] = {0};
  uint16_t VarValue = 0;
  uint16_t saveValue = 0;

  uint16_t counter = 0;
#else
  uint8_t nunchuk_connected = 1;
#endif

#if defined(CONTROL_ADC) && defined(ADC_PROTECT_ENA)
static int16_t timeoutCntADC   = 0;  // Timeout counter for ADC Protection
#endif
static uint8_t timeoutFlagADC  = 0;  // Timeout Flag for for ADC Protection: 0 = OK, 1 = Problem detected (line disconnected or wrong ADC data)

#if defined(CONTROL_SERIAL_USART2) || defined(CONTROL_SERIAL_USART3)
  #ifdef CONTROL_IBUS
    static uint16_t ibus_chksum;
    static uint16_t ibus_captured_value[IBUS_NUM_CHANNELS];
    
    typedef struct{
      uint8_t  start;
      uint8_t  type; 
      uint8_t  channels[IBUS_NUM_CHANNELS*2];
      uint8_t  checksuml;
      uint8_t  checksumh;    
    } Serialcommand;
  #else
    typedef struct{
      uint16_t  start; 
      int16_t   steer;
      int16_t   speed;
      uint16_t  checksum;    
    } Serialcommand;
  #endif
static volatile Serialcommand command;
static int16_t timeoutCntSerial   = 0;  // Timeout counter for Rx Serial command
#endif
static uint8_t timeoutFlagSerial  = 0;  // Timeout Flag for Rx Serial command: 0 = OK, 1 = Problem detected (line disconnected or wrong Rx data)

#if defined(FEEDBACK_SERIAL_USART2) || defined(FEEDBACK_SERIAL_USART3)
typedef struct{
  uint16_t  start;
  int16_t   cmd1;
  int16_t   cmd2;
  int16_t   speedR;
  int16_t   speedL;
  int16_t   speedR_meas;
  int16_t   speedL_meas;
  int16_t   batVoltage;
  int16_t   boardTemp;
  uint16_t  checksum;
} SerialFeedback;
static SerialFeedback Feedback;
#endif

#if defined(CONTROL_NUNCHUK) || defined(SUPPORT_NUNCHUK) || defined(CONTROL_PPM) || defined(CONTROL_ADC)
static uint8_t button1, button2;
#endif

uint8_t ctrlModReqRaw = CTRL_MOD_REQ;
uint8_t ctrlModReq    = CTRL_MOD_REQ;   // Final control mode request
static int        cmd1;                 // normalized input value. -1000 to 1000
static int        cmd2;                 // normalized input value. -1000 to 1000
static int16_t    speed;                // local variable for speed. -1000 to 1000
#ifndef VARIANT_TRANSPOTTER
  static int16_t  steer;                // local variable for steering. -1000 to 1000
  static int16_t  steerRateFixdt;       // local fixed-point variable for steering rate limiter
  static int16_t  speedRateFixdt;       // local fixed-point variable for speed rate limiter
  static int32_t  steerFixdt;           // local fixed-point variable for steering low-pass filter
  static int32_t  speedFixdt;           // local fixed-point variable for speed low-pass filter
#endif
#ifdef VARIANT_HOVERCAR
  static MultipleTap MultipleTapBreak;  // define multiple tap functionality for the Break pedal
#endif
static int16_t    speedAvg;             // average measured speed
static int16_t    speedAvgAbs;          // average measured speed in absolute

extern volatile int pwml;               // global variable for pwm left. -1000 to 1000
extern volatile int pwmr;               // global variable for pwm right. -1000 to 1000

extern uint8_t buzzerFreq;              // global variable for the buzzer pitch. can be 1, 2, 3, 4, 5, 6, 7...
extern uint8_t buzzerPattern;           // global variable for the buzzer pattern. can be 1, 2, 3, 4, 5, 6, 7...

extern uint8_t enable;                  // global variable for motor enable

extern volatile uint32_t timeout;       // global variable for timeout
extern int16_t batVoltage;              // global variable for battery voltage

static uint32_t inactivity_timeout_counter;
static uint32_t main_loop_counter;

extern uint8_t nunchuk_data[6];
#ifdef CONTROL_PPM
extern volatile uint16_t ppm_captured_value[PPM_NUM_CHANNELS+1];
#endif


void poweroff(void) {
  //  if (abs(speed) < 20) {  // wait for the speed to drop, then shut down -> this is commented out for SAFETY reasons
        buzzerPattern = 0;
        enable = 0;
        consoleLog("-- Motors disabled --\r\n");
        for (int i = 0; i < 8; i++) {
            buzzerFreq = (uint8_t)i;
            HAL_Delay(100);
        }
        HAL_GPIO_WritePin(OFF_PORT, OFF_PIN, 0);
        while(1) {}
  //  }
}


int main(void) {

  HAL_Init();
  __HAL_RCC_AFIO_CLK_ENABLE();
  HAL_NVIC_SetPriorityGrouping(NVIC_PRIORITYGROUP_4);
  /* System interrupt init*/
  /* MemoryManagement_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(MemoryManagement_IRQn, 0, 0);
  /* BusFault_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(BusFault_IRQn, 0, 0);
  /* UsageFault_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(UsageFault_IRQn, 0, 0);
  /* SVCall_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(SVCall_IRQn, 0, 0);
  /* DebugMonitor_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DebugMonitor_IRQn, 0, 0);
  /* PendSV_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(PendSV_IRQn, 0, 0);
  /* SysTick_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);

  SystemClock_Config();

  __HAL_RCC_DMA1_CLK_DISABLE();
  MX_GPIO_Init();
  MX_TIM_Init();
  MX_ADC1_Init();
  MX_ADC2_Init();

  HAL_GPIO_WritePin(OFF_PORT, OFF_PIN, 1);

  HAL_ADC_Start(&hadc1);
  HAL_ADC_Start(&hadc2);

// Matlab Init
// ###############################################################################
  
  /* Set BLDC controller parameters */ 
  rtP_Left.b_selPhaABCurrMeas   = 1;            // Left motor measured current phases = {iA, iB} -> do NOT change
  rtP_Left.z_ctrlTypSel         = CTRL_TYP_SEL;
  rtP_Left.b_diagEna            = DIAG_ENA; 
  rtP_Left.i_max                = (I_MOT_MAX * A2BIT_CONV) << 4;        // fixdt(1,16,4)
  rtP_Left.n_max                = N_MOT_MAX << 4;                       // fixdt(1,16,4)
  rtP_Left.b_fieldWeakEna       = FIELD_WEAK_ENA; 
  rtP_Left.id_fieldWeakMax      = (FIELD_WEAK_MAX * A2BIT_CONV) << 4;   // fixdt(1,16,4)
  rtP_Left.a_phaAdvMax          = PHASE_ADV_MAX << 4;                   // fixdt(1,16,4)
  rtP_Left.r_fieldWeakHi        = FIELD_WEAK_HI << 4;                   // fixdt(1,16,4)
  rtP_Left.r_fieldWeakLo        = FIELD_WEAK_LO << 4;                   // fixdt(1,16,4)

  rtP_Right                     = rtP_Left;     // Copy the Left motor parameters to the Right motor parameters
  rtP_Right.b_selPhaABCurrMeas  = 0;            // Left motor measured current phases = {iB, iC} -> do NOT change

  /* Pack LEFT motor data into RTM */
  rtM_Left->defaultParam        = &rtP_Left;
  rtM_Left->dwork               = &rtDW_Left;
  rtM_Left->inputs              = &rtU_Left;
  rtM_Left->outputs             = &rtY_Left;

  /* Pack RIGHT motor data into RTM */
  rtM_Right->defaultParam       = &rtP_Right;
  rtM_Right->dwork              = &rtDW_Right;
  rtM_Right->inputs             = &rtU_Right;
  rtM_Right->outputs            = &rtY_Right;

  /* Initialize BLDC controllers */
  BLDC_controller_initialize(rtM_Left);
  BLDC_controller_initialize(rtM_Right);

// ###############################################################################

  for (int i = 8; i >= 0; i--) {
    buzzerFreq = (uint8_t)i;
    HAL_Delay(100);
  }
  buzzerFreq = 0;

  HAL_GPIO_WritePin(LED_PORT, LED_PIN, 1);

  #ifdef VARIANT_TRANSPOTTER
    int  lastDistance = 0;
    enable = 1;
    uint8_t checkRemote = 0;

    HAL_FLASH_Unlock();

    /* EEPROM Init */
    EE_Init();

    EE_ReadVariable(VirtAddVarTab[0], &saveValue);

    HAL_FLASH_Lock();
    float setDistance = saveValue / 1000.0;
    if (setDistance < 0.2) {
      setDistance = 1.0;
    }
  #endif

  #ifdef CONTROL_PPM
    PPM_Init();
  #endif

  #ifdef CONTROL_NUNCHUK
    I2C_Init();
    Nunchuk_Init();
  #endif

  #if defined(CONTROL_SERIAL_USART2) || defined(FEEDBACK_SERIAL_USART2) || defined(DEBUG_SERIAL_USART2)
    UART2_Init();
    huart = huart2;
  #endif
  #if defined(CONTROL_SERIAL_USART3) || defined(FEEDBACK_SERIAL_USART3) || defined(DEBUG_SERIAL_USART3)
    UART3_Init();
    huart = huart3;
  #endif
  #if defined(CONTROL_SERIAL_USART2) || defined(CONTROL_SERIAL_USART3)
    HAL_UART_Receive_DMA(&huart, (uint8_t *)&command, sizeof(command));
  #endif

  #if defined(DEBUG_I2C_LCD) || defined(SUPPORT_LCD)
    I2C_Init();
    HAL_Delay(50);
    lcd.pcf8574.PCF_I2C_ADDRESS = 0x27;
      lcd.pcf8574.PCF_I2C_TIMEOUT = 5;
      lcd.pcf8574.i2c = hi2c2;
      lcd.NUMBER_OF_LINES = NUMBER_OF_LINES_2;
      lcd.type = TYPE0;

      if(LCD_Init(&lcd)!=LCD_OK){
          // error occured
          //TODO while(1);
      }

    LCD_ClearDisplay(&lcd);
    HAL_Delay(5);
    LCD_SetLocation(&lcd, 0, 0);
    #ifdef VARIANT_TRANSPOTTER
      LCD_WriteString(&lcd, "TranspOtter V2.1");
    #else
      LCD_WriteString(&lcd, "Hover V2.0");
    #endif
    LCD_SetLocation(&lcd, 0, 1);
    LCD_WriteString(&lcd, "Initializing...");
  #endif

  #if defined(VARIANT_TRANSPOTTER) && defined(SUPPORT_LCD)
    LCD_ClearDisplay(&lcd);
    HAL_Delay(5);
    LCD_SetLocation(&lcd, 0, 1);
    LCD_WriteString(&lcd, "Bat:");
    LCD_SetLocation(&lcd, 8, 1);
    LCD_WriteString(&lcd, "V");

    LCD_SetLocation(&lcd, 15, 1);
    LCD_WriteString(&lcd, "A");

    LCD_SetLocation(&lcd, 0, 0);
    LCD_WriteString(&lcd, "Len:");
    LCD_SetLocation(&lcd, 8, 0);
    LCD_WriteString(&lcd, "m(");
    LCD_SetLocation(&lcd, 14, 0);
    LCD_WriteString(&lcd, "m)");
  #endif

  int16_t lastSpeedL = 0, lastSpeedR = 0;
  int16_t speedL = 0, speedR = 0;

  int32_t board_temp_adcFixdt = adc_buffer.temp << 20;  // Fixed-point filter output initialized with current ADC converted to fixed-point
  int16_t board_temp_adcFilt  = adc_buffer.temp;
  int16_t board_temp_deg_c;


  while(1) {
    HAL_Delay(DELAY_IN_MAIN_LOOP); //delay in ms

    #ifdef VARIANT_TRANSPOTTER
      if(HAL_GPIO_ReadPin(BUTTON_PORT, BUTTON_PIN)) {
        enable = 0;
        while(HAL_GPIO_ReadPin(BUTTON_PORT, BUTTON_PIN)) {
          HAL_Delay(10);
        }
        shortBeep(5);
        HAL_Delay(300);
        if (HAL_GPIO_ReadPin(BUTTON_PORT, BUTTON_PIN)) {
          while(HAL_GPIO_ReadPin(BUTTON_PORT, BUTTON_PIN)) {
            HAL_Delay(10);
          }
          longBeep(5);
          HAL_Delay(350);
          poweroff();
        } else {
          setDistance += 0.25;
          if (setDistance > 2.6) {
            setDistance = 0.5;
          }
          shortBeep(setDistance / 0.25);
          saveValue = setDistance * 1000;
          saveConfig();
        }
      }

      #ifdef GAMETRAK_CONNECTION_NORMAL
        uint16_t distance = CLAMP((adc_buffer.l_rx2) - 180, 0, 4095);
        steering = (adc_buffer.l_tx2 - 2048) / 2048.0;
      #endif
      #ifdef GAMETRAK_CONNECTION_ALTERNATE
        uint16_t distance = CLAMP((adc_buffer.l_tx2) - 180, 0, 4095);
        steering = (adc_buffer.l_rx2 - 2048) / 2048.0;
      #endif

      feedforward = ((distance - (int)(setDistance * 1345)));

      if (nunchuk_connected == 0) {
        speedL = speedL * 0.8f + (CLAMP(feedforward +  ((steering)*((float)MAX(ABS(feedforward), 50)) * ROT_P), -850, 850) * -0.2f);
        speedR = speedR * 0.8f + (CLAMP(feedforward -  ((steering)*((float)MAX(ABS(feedforward), 50)) * ROT_P), -850, 850) * -0.2f);
        if ((speedL < lastSpeedL + 50 && speedL > lastSpeedL - 50) && (speedR < lastSpeedR + 50 && speedR > lastSpeedR - 50)) {
          if (distance - (int)(setDistance * 1345) > 0) {
            enable = 1;
          }
          if (distance - (int)(setDistance * 1345) > -300) {
            #ifdef INVERT_R_DIRECTION
              pwmr = speedR;
            #endif
            #ifndef INVERT_R_DIRECTION
              pwmr = -speedR;
            #endif
            #ifdef INVERT_L_DIRECTION
              pwml = -speedL;
            #endif
            #ifndef INVERT_L_DIRECTION
              pwml = speedL;
            #endif

            if (checkRemote) {
              if (!HAL_GPIO_ReadPin(LED_PORT, LED_PIN)) {
                //enable = 1;
              } else {
                enable = 0;
              }
            }
          } else {
            enable = 0;
          }
        }
        lastSpeedL = speedL;
        lastSpeedR = speedR;

        timeout = 0;
      }
    #endif

    #if defined(CONTROL_NUNCHUK) || defined(SUPPORT_NUNCHUK)
      if (nunchuk_connected != 0) {
        Nunchuk_Read();
        cmd1 = CLAMP((nunchuk_data[0] - 127) * 8, INPUT_MIN, INPUT_MAX); // x - axis. Nunchuk joystick readings range 30 - 230
        cmd2 = CLAMP((nunchuk_data[1] - 128) * 8, INPUT_MIN, INPUT_MAX); // y - axis

        button1 = (uint8_t)nunchuk_data[5] & 1;
        button2 = (uint8_t)(nunchuk_data[5] >> 1) & 1;
      }
    #endif

    #ifdef CONTROL_PPM
      cmd1 = CLAMP((ppm_captured_value[0] - INPUT_MID) * 2, INPUT_MIN, INPUT_MAX);
      cmd2 = CLAMP((ppm_captured_value[1] - INPUT_MID) * 2, INPUT_MIN, INPUT_MAX);
      button1 = ppm_captured_value[5] > INPUT_MID;
      button2 = 0;
      // float scale = ppm_captured_value[2] / 1000.0f;     // not used for now, uncomment if needed
    #endif

    #ifdef CONTROL_ADC
      // ADC values range: 0-4095, see ADC-calibration in config.h
      #ifdef ADC1_MID_POT
        cmd1 = CLAMP((adc_buffer.l_tx2 - ADC1_MID) * INPUT_MAX / (ADC1_MAX - ADC1_MID), 0, INPUT_MAX) 
              -CLAMP((ADC1_MID - adc_buffer.l_tx2) * INPUT_MAX / (ADC1_MID - ADC1_MIN), 0, INPUT_MAX);    // ADC1        
      #else
        cmd1 = CLAMP((adc_buffer.l_tx2 - ADC1_MIN) * INPUT_MAX / (ADC1_MAX - ADC1_MIN), 0, INPUT_MAX);    // ADC1
      #endif

      #ifdef ADC2_MID_POT
        cmd2 = CLAMP((adc_buffer.l_rx2 - ADC2_MID) * INPUT_MAX / (ADC2_MAX - ADC2_MID), 0, INPUT_MAX)  
              -CLAMP((ADC2_MID - adc_buffer.l_rx2) * INPUT_MAX / (ADC2_MID - ADC2_MIN), 0, INPUT_MAX);    // ADC2        
      #else
        cmd2 = CLAMP((adc_buffer.l_rx2 - ADC2_MIN) * INPUT_MAX / (ADC2_MAX - ADC2_MIN), 0, INPUT_MAX);    // ADC2
      #endif

      #ifdef ADC_PROTECT_ENA
        if (adc_buffer.l_tx2 >= (ADC1_MIN - ADC_PROTECT_THRESH) && adc_buffer.l_tx2 <= (ADC1_MAX + ADC_PROTECT_THRESH) && 
            adc_buffer.l_rx2 >= (ADC2_MIN - ADC_PROTECT_THRESH) && adc_buffer.l_rx2 <= (ADC2_MAX + ADC_PROTECT_THRESH)) {
          if (timeoutFlagADC) {                         // Check for previous timeout flag  
            if (timeoutCntADC-- <= 0)                   // Timeout de-qualification
              timeoutFlagADC  = 0;                      // Timeout flag cleared           
          } else {
            timeoutCntADC     = 0;                      // Reset the timeout counter         
          }
        } else {
          if (timeoutCntADC++ >= ADC_PROTECT_TIMEOUT) { // Timeout qualification
            timeoutFlagADC    = 1;                      // Timeout detected
            timeoutCntADC     = ADC_PROTECT_TIMEOUT;    // Limit timout counter value
          }
        }

        if (timeoutFlagADC) {                           // In case of timeout bring the system to a Safe State
          ctrlModReq  = 0;                              // OPEN_MODE request. This will bring the motor power to 0 in a controlled way
          cmd1        = 0;
          cmd2        = 0;
        } else {
          ctrlModReq  = ctrlModReqRaw;                  // Follow the Mode request
        }
      #endif

      // use ADCs as button inputs:
      button1 = (uint8_t)(adc_buffer.l_tx2 > 2000);  // ADC1
      button2 = (uint8_t)(adc_buffer.l_rx2 > 2000);  // ADC2

      timeout = 0;
    #endif

    #if defined CONTROL_SERIAL_USART2 || defined CONTROL_SERIAL_USART3

      // Handle received data validity, timeout and fix out-of-sync if necessary
      #ifdef CONTROL_IBUS
        ibus_chksum = 0xFFFF - IBUS_LENGTH - IBUS_COMMAND;
        for (uint8_t i = 0; i < (IBUS_NUM_CHANNELS * 2); i++) {
          ibus_chksum -= command.channels[i];
        }
        if (command.start == IBUS_LENGTH && command.type == IBUS_COMMAND && ibus_chksum == (uint16_t)((command.checksumh << 8) + command.checksuml)) {
          if (timeoutFlagSerial) {                      // Check for previous timeout flag  
            if (timeoutCntSerial-- <= 0)                // Timeout de-qualification
              timeoutFlagSerial = 0;                    // Timeout flag cleared           
          } else {         
            for (uint8_t i = 0; i < (IBUS_NUM_CHANNELS * 2); i+=2) {
              ibus_captured_value[(i/2)] = CLAMP(command.channels[i] + (command.channels[i+1] << 8) - 1000, 0, INPUT_MAX); // 1000-2000 -> 0-1000
            }
            cmd1              = CLAMP((ibus_captured_value[0] - INPUT_MID) * 2, INPUT_MIN, INPUT_MAX);
            cmd2              = CLAMP((ibus_captured_value[1] - INPUT_MID) * 2, INPUT_MIN, INPUT_MAX);
            command.start     = 0xFF;                   // Change the Start Frame for timeout detection in the next cycle
            timeoutCntSerial  = 0;                      // Reset the timeout counter
          }
        } else {
          if (timeoutCntSerial++ >= SERIAL_TIMEOUT) {   // Timeout qualification
            timeoutFlagSerial = 1;                      // Timeout detected
            timeoutCntSerial  = SERIAL_TIMEOUT;         // Limit timout counter value
          }
          // Check periodically the received Start Frame. If it is NOT OK, most probably we are out-of-sync. Try to re-sync by reseting the DMA
          if (main_loop_counter % 25 == 0 && command.start != IBUS_LENGTH && command.start != 0xFF) {
            HAL_UART_DMAStop(&huart);                
            HAL_UART_Receive_DMA(&huart, (uint8_t *)&command, sizeof(command));
          }
        }  
      #else
        if (command.start == START_FRAME && command.checksum == (uint16_t)(command.start ^ command.steer ^ command.speed)) {
          if (timeoutFlagSerial) {                      // Check for previous timeout flag  
            if (timeoutCntSerial-- <= 0)                // Timeout de-qualification
              timeoutFlagSerial = 0;                    // Timeout flag cleared           
          } else {
            cmd1              = CLAMP((int16_t)command.steer, INPUT_MIN, INPUT_MAX);
            cmd2              = CLAMP((int16_t)command.speed, INPUT_MIN, INPUT_MAX);
            command.start     = 0xFFFF;                 // Change the Start Frame for timeout detection in the next cycle
            timeoutCntSerial  = 0;                      // Reset the timeout counter         
          }
        } else {
          if (timeoutCntSerial++ >= SERIAL_TIMEOUT) {   // Timeout qualification
            timeoutFlagSerial = 1;                      // Timeout detected
            timeoutCntSerial  = SERIAL_TIMEOUT;         // Limit timout counter value
          }
          // Check periodically the received Start Frame. If it is NOT OK, most probably we are out-of-sync. Try to re-sync by reseting the DMA
          if (main_loop_counter % 25 == 0 && command.start != START_FRAME && command.start != 0xFFFF) {
            HAL_UART_DMAStop(&huart);                
            HAL_UART_Receive_DMA(&huart, (uint8_t *)&command, sizeof(command));
          }
        }
      #endif     

      if (timeoutFlagSerial) {                          // In case of timeout bring the system to a Safe State
        ctrlModReq  = 0;                                // OPEN_MODE request. This will bring the motor power to 0 in a controlled way
        cmd1        = 0;
        cmd2        = 0;
      } else {
        ctrlModReq  = ctrlModReqRaw;                    // Follow the Mode request
      }
      timeout = 0;

    #endif

    // Calculate measured average speed. The minus sign (-) is beacause motors spin in opposite directions
    #if   !defined(INVERT_L_DIRECTION) && !defined(INVERT_R_DIRECTION)
      speedAvg    = ( rtY_Left.n_mot - rtY_Right.n_mot) / 2;
    #elif !defined(INVERT_L_DIRECTION) &&  defined(INVERT_R_DIRECTION)
      speedAvg    = ( rtY_Left.n_mot + rtY_Right.n_mot) / 2;
    #elif  defined(INVERT_L_DIRECTION) && !defined(INVERT_R_DIRECTION)
      speedAvg    = (-rtY_Left.n_mot - rtY_Right.n_mot) / 2;
    #elif  defined(INVERT_L_DIRECTION) &&  defined(INVERT_R_DIRECTION)
      speedAvg    = (-rtY_Left.n_mot + rtY_Right.n_mot) / 2;
    #endif

    // Handle the case when SPEED_COEFFICIENT sign is negative (which is when most significant bit is 1)
    if ((SPEED_COEFFICIENT & (1 << 16)) >> 16) {
      speedAvg    = -speedAvg;
    } 
    speedAvgAbs   = abs(speedAvg);

    #ifndef VARIANT_TRANSPOTTER
      // ####### MOTOR ENABLING: Only if the initial input is very small (for SAFETY) #######
      if (enable == 0 && (!errCode_Left && !errCode_Right) && (cmd1 > -50 && cmd1 < 50) && (cmd2 > -50 && cmd2 < 50)){
        shortBeep(6);                     // make 2 beeps indicating the motor enable
        shortBeep(4); HAL_Delay(100);
        enable = 1;                       // enable motors
      }

      // ####### VARIANT_HOVERCAR #######
      #ifdef VARIANT_HOVERCAR
        // Calculate speed Blend, a number between [0, 1] in fixdt(0,16,15)
        uint16_t speedBlend;       
        speedBlend = (uint16_t)(((CLAMP(speedAvgAbs,30,90) - 30) << 15) / 60);     // speedBlend [0,1] is within [30 rpm, 90rpm]

        // Check if Hovercar is physically close to standstill to enable Double tap detection on Brake pedal for Reverse functionality
        if (speedAvgAbs < 20) {
          multipleTapDet(cmd1, HAL_GetTick(), &MultipleTapBreak);   // Break pedal in this case is "cmd1" variable
        }

        // If Brake pedal (cmd1) is pressed, bring to 0 also the Throttle pedal (cmd2) to avoid "Double pedal" driving          
        if (cmd1 > 20) {
          cmd2 = (int16_t)((cmd2 * speedBlend) >> 15);
        }

        // Make sure the Brake pedal is opposite to the direction of motion AND it goes to 0 as we reach standstill (to avoid Reverse driving by Brake pedal) 
        if (speedAvg > 0) {
          cmd1 = (int16_t)((-cmd1 * speedBlend) >> 15);
        } else {
          cmd1 = (int16_t)(( cmd1 * speedBlend) >> 15);          
        }
      #endif

      // ####### LOW-PASS FILTER #######
      rateLimiter16(cmd1, RATE, &steerRateFixdt);
      rateLimiter16(cmd2, RATE, &speedRateFixdt);
      filtLowPass32(steerRateFixdt >> 4, FILTER, &steerFixdt);
      filtLowPass32(speedRateFixdt >> 4, FILTER, &speedFixdt);
      steer = (int16_t)(steerFixdt >> 20);  // convert fixed-point to integer
      speed = (int16_t)(speedFixdt >> 20);  // convert fixed-point to integer    

      // ####### VARIANT_HOVERCAR #######
      #ifdef VARIANT_HOVERCAR        
        if (!MultipleTapBreak.b_multipleTap) {  // Check driving direction
          speed = steer + speed;                // Forward driving          
        } else {
          speed = steer - speed;                // Reverse driving
        }
      #endif

      // ####### MIXER #######
      // speedR = CLAMP((int)(speed * SPEED_COEFFICIENT -  steer * STEER_COEFFICIENT), -1000, 1000);
      // speedL = CLAMP((int)(speed * SPEED_COEFFICIENT +  steer * STEER_COEFFICIENT), -1000, 1000);
      mixerFcn(speed << 4, steer << 4, &speedR, &speedL);   // This function implements the equations above

      #ifdef ADDITIONAL_CODE
        ADDITIONAL_CODE;
      #endif


      // ####### SET OUTPUTS (if the target change is less than +/- 50) #######
      if ((speedL > lastSpeedL-50 && speedL < lastSpeedL+50) && (speedR > lastSpeedR-50 && speedR < lastSpeedR+50) && timeout < TIMEOUT) {
        #ifdef INVERT_R_DIRECTION
          pwmr = speedR;
        #else
          pwmr = -speedR;
        #endif
        #ifdef INVERT_L_DIRECTION
          pwml = -speedL;
        #else
          pwml = speedL;
        #endif
      }
    #endif

    lastSpeedL = speedL;
    lastSpeedR = speedR;

    #ifdef VARIANT_TRANSPOTTER
      if (timeout > TIMEOUT) {
        pwml = 0;
        pwmr = 0;
        enable = 0;
        #ifdef SUPPORT_LCD
          LCD_SetLocation(&lcd, 0, 0);
          LCD_WriteString(&lcd, "Len:");
          LCD_SetLocation(&lcd, 8, 0);
          LCD_WriteString(&lcd, "m(");
          LCD_SetLocation(&lcd, 14, 0);
          LCD_WriteString(&lcd, "m)");
        #endif

        HAL_Delay(1000);

        nunchuk_connected = 0;
      }

      if ((distance / 1345.0) - setDistance > 0.5 && (lastDistance / 1345.0) - setDistance > 0.5) { // Error, robot too far away!
        enable = 0;
        longBeep(5);
        #ifdef SUPPORT_LCD
          LCD_ClearDisplay(&lcd);
          HAL_Delay(5);
          LCD_SetLocation(&lcd, 0, 0);
          LCD_WriteString(&lcd, "Emergency Off!");
          LCD_SetLocation(&lcd, 0, 1);
          LCD_WriteString(&lcd, "Keeper too fast.");
        #endif
        poweroff();
      }

      #ifdef SUPPORT_NUNCHUK
        if (counter % 500 == 0) {
          if (nunchuk_connected == 0 && enable == 0) {
            if (Nunchuk_Ping()) {
              HAL_Delay(500);
              Nunchuk_Init();
              #ifdef SUPPORT_LCD
                LCD_SetLocation(&lcd, 0, 0);
                LCD_WriteString(&lcd, "Nunchuk Control");
              #endif
              timeout = 0;
              HAL_Delay(1000);
              nunchuk_connected = 1;
            }
          }
        }   
      #endif

      #ifdef SUPPORT_LCD
        if (counter % 100 == 0) {
          if (LCDerrorFlag == 1 && enable == 0) {

          } else {
            if (nunchuk_connected == 0) {
              LCD_SetLocation(&lcd, 4, 0);
              LCD_WriteFloat(&lcd,distance/1345.0,2);
              LCD_SetLocation(&lcd, 10, 0);
              LCD_WriteFloat(&lcd,setDistance,2);
            }
            LCD_SetLocation(&lcd, 4, 1);
            LCD_WriteFloat(&lcd,batVoltage, 1);
            LCD_SetLocation(&lcd, 11, 1);
            //LCD_WriteFloat(&lcd,MAX(ABS(currentR), ABS(currentL)),2);
          }
        }
      #endif

      counter++;
    #endif


    // ####### CALC BOARD TEMPERATURE #######
    filtLowPass32(adc_buffer.temp, TEMP_FILT_COEF, &board_temp_adcFixdt);
    board_temp_adcFilt  = (int16_t)(board_temp_adcFixdt >> 20);  // convert fixed-point to integer
    board_temp_deg_c    = (TEMP_CAL_HIGH_DEG_C - TEMP_CAL_LOW_DEG_C) * (board_temp_adcFilt - TEMP_CAL_LOW_ADC) / (TEMP_CAL_HIGH_ADC - TEMP_CAL_LOW_ADC) + TEMP_CAL_LOW_DEG_C;

    if (main_loop_counter % 25 == 0) {    // Send data periodically

      // ####### DEBUG SERIAL OUT #######
      #if defined(DEBUG_SERIAL_USART2) || defined(DEBUG_SERIAL_USART3)
        #ifdef CONTROL_ADC
          setScopeChannel(0, (int16_t)adc_buffer.l_tx2);        // 1: ADC1
          setScopeChannel(1, (int16_t)adc_buffer.l_rx2);        // 2: ADC2
        #endif
        setScopeChannel(2, (int16_t)speedR);                    // 3: output command: [-1000, 1000]
        setScopeChannel(3, (int16_t)speedL);                    // 4: output command: [-1000, 1000]
        setScopeChannel(4, (int16_t)adc_buffer.batt1);          // 5: for battery voltage calibration
        setScopeChannel(5, (int16_t)(batVoltage * BAT_CALIB_REAL_VOLTAGE / BAT_CALIB_ADC)); // 6: for verifying battery voltage calibration
        setScopeChannel(6, (int16_t)board_temp_adcFilt);        // 7: for board temperature calibration
        setScopeChannel(7, (int16_t)board_temp_deg_c);          // 8: for verifying board temperature calibration
        consoleScope();

      // ####### FEEDBACK SERIAL OUT #######
      #elif defined(FEEDBACK_SERIAL_USART2) || defined(FEEDBACK_SERIAL_USART3)
        if(UART_DMA_CHANNEL->CNDTR == 0) {
          Feedback.start	        = (uint16_t)START_FRAME;
          Feedback.cmd1           = (int16_t)cmd1;
          Feedback.cmd2           = (int16_t)cmd2;
          Feedback.speedR	        = (int16_t)speedR;
          Feedback.speedL	        = (int16_t)speedL;
          Feedback.speedR_meas	  = (int16_t)rtY_Left.n_mot;
          Feedback.speedL_meas	  = (int16_t)rtY_Right.n_mot;
          Feedback.batVoltage	    = (int16_t)(batVoltage * BAT_CALIB_REAL_VOLTAGE / BAT_CALIB_ADC);
          Feedback.boardTemp	    = (int16_t)board_temp_deg_c;
          Feedback.checksum       = (uint16_t)(Feedback.start ^ Feedback.cmd1 ^ Feedback.cmd2 ^ Feedback.speedR ^ Feedback.speedL
                                    ^ Feedback.speedR_meas ^ Feedback.speedL_meas ^ Feedback.batVoltage ^ Feedback.boardTemp); 

          UART_DMA_CHANNEL->CCR  &= ~DMA_CCR_EN;
          UART_DMA_CHANNEL->CNDTR = sizeof(Feedback);
          UART_DMA_CHANNEL->CMAR  = (uint32_t)&Feedback;
          UART_DMA_CHANNEL->CCR  |= DMA_CCR_EN;          
        }
      #endif      
    }    

    HAL_GPIO_TogglePin(LED_PORT, LED_PIN);
    // ####### POWEROFF BY POWER-BUTTON #######
    if (HAL_GPIO_ReadPin(BUTTON_PORT, BUTTON_PIN)) {
      enable = 0;                                             // disable motors
      while (HAL_GPIO_ReadPin(BUTTON_PORT, BUTTON_PIN)) {}    // wait until button is released
      if(__HAL_RCC_GET_FLAG(RCC_FLAG_SFTRST)) {               // do not power off after software reset (from a programmer/debugger)
        __HAL_RCC_CLEAR_RESET_FLAGS();                        // clear reset flags
      } else {
        poweroff();                                           // release power-latch
      }
    }


    // ####### BEEP AND EMERGENCY POWEROFF #######
    if (errCode_Left || errCode_Right) {    // disable motors and beep in case of Motor error - fast beep
      enable        = 0;
      buzzerFreq    = 8;
      buzzerPattern = 1;
    } else if ((TEMP_POWEROFF_ENABLE && board_temp_deg_c >= TEMP_POWEROFF && speedAvgAbs < 20) || (batVoltage < BAT_LOW_DEAD && speedAvgAbs < 20)) {  // poweroff before mainboard burns OR low bat 3
      poweroff();
    } else if (TEMP_WARNING_ENABLE && board_temp_deg_c >= TEMP_WARNING) {  // beep if mainboard gets hot
      buzzerFreq    = 4;
      buzzerPattern = 1;
    } else if (batVoltage < BAT_LOW_LVL1 && batVoltage >= BAT_LOW_LVL2 && BAT_LOW_LVL1_ENABLE) {  // low bat 1: slow beep
      buzzerFreq    = 5;
      buzzerPattern = 42;
    } else if (batVoltage < BAT_LOW_LVL2 && batVoltage >= BAT_LOW_DEAD && BAT_LOW_LVL2_ENABLE) {  // low bat 2: fast beep
      buzzerFreq    = 5;
      buzzerPattern = 6;
    } else if (timeoutFlagADC || timeoutFlagSerial) {  // beep in case of ADC or Serial timeout - fast beep      
      buzzerFreq    = 24;
      buzzerPattern = 1;
    } else if (BEEPS_BACKWARD && speed < -50 && speedAvg < 0) {  // backward beep
      buzzerFreq    = 5;
      buzzerPattern = 1;
    } else {  // do not beep
      buzzerFreq    = 0;
      buzzerPattern = 0;
    }


    // ####### INACTIVITY TIMEOUT #######
    if (abs(speedL) > 50 || abs(speedR) > 50) {
      inactivity_timeout_counter = 0;
    } else {
      inactivity_timeout_counter ++;
    }
    if (inactivity_timeout_counter > (INACTIVITY_TIMEOUT * 60 * 1000) / (DELAY_IN_MAIN_LOOP + 1)) {  // rest of main loop needs maybe 1ms
      poweroff();
    }

    main_loop_counter++;
    timeout++;
  }
}

#ifdef VARIANT_TRANSPOTTER
  void saveConfig() {
    HAL_FLASH_Unlock();
    EE_WriteVariable(VirtAddVarTab[0], saveValue);
    HAL_FLASH_Lock();
  }
#endif

void longBeep(uint8_t freq){
    buzzerFreq = freq;
    HAL_Delay(500);
    buzzerFreq = 0;
}

void shortBeep(uint8_t freq){
    buzzerFreq = freq;
    HAL_Delay(100);
    buzzerFreq = 0;
}

// ===========================================================
  /* Low pass filter fixed-point 32 bits: fixdt(1,32,20)
  * Max:  2047.9375
  * Min: -2048
  * Res:  0.0625
  * 
  * Inputs:       u     = int16
  * Outputs:      y     = fixdt(1,32,20)
  * Parameters:   coef  = fixdt(0,16,16) = [0,65535U]
  * 
  * Example: 
  * If coef = 0.8 (in floating point), then coef = 0.8 * 2^16 = 52429 (in fixed-point)
  * filtLowPass16(u, 52429, &y);
  * yint = (int16_t)(y >> 20); // the integer output is the fixed-point ouput shifted by 20 bits
  */
void filtLowPass32(int16_t u, uint16_t coef, int32_t *y)
{
  int32_t tmp;
  
  tmp = (int16_t)(u << 4) - (*y >> 16);  
  tmp = CLAMP(tmp, -32768, 32767);  // Overflow protection  
  *y  = coef * tmp + (*y);
}

// ===========================================================
  /* mixerFcn(rtu_speed, rtu_steer, &rty_speedR, &rty_speedL); 
  * Inputs:       rtu_speed, rtu_steer                  = fixdt(1,16,4)
  * Outputs:      rty_speedR, rty_speedL                = int16_t
  * Parameters:   SPEED_COEFFICIENT, STEER_COEFFICIENT  = fixdt(0,16,14)
  */
void mixerFcn(int16_t rtu_speed, int16_t rtu_steer, int16_t *rty_speedR, int16_t *rty_speedL)
{
  int16_t prodSpeed;
  int16_t prodSteer;
  int32_t tmp;

  prodSpeed   = (int16_t)((rtu_speed * (int16_t)SPEED_COEFFICIENT) >> 14);
  prodSteer   = (int16_t)((rtu_steer * (int16_t)STEER_COEFFICIENT) >> 14);

  tmp         = prodSpeed - prodSteer;  
  tmp         = CLAMP(tmp, -32768, 32767);  // Overflow protection
  *rty_speedR = (int16_t)(tmp >> 4);        // Convert from fixed-point to int 
  *rty_speedR = CLAMP(*rty_speedR, INPUT_MIN, INPUT_MAX);

  tmp         = prodSpeed + prodSteer;
  tmp         = CLAMP(tmp, -32768, 32767);  // Overflow protection
  *rty_speedL = (int16_t)(tmp >> 4);        // Convert from fixed-point to int
  *rty_speedL = CLAMP(*rty_speedL, INPUT_MIN, INPUT_MAX);
}

// ===========================================================
  /* rateLimiter16(int16_t u, int16_t rate, int16_t *y);
  * Inputs:       u     = int16
  * Outputs:      y     = fixdt(1,16,4)
  * Parameters:   rate  = fixdt(1,16,4) = [0, 32767] Do NOT make rate negative (>32767)
  */
void rateLimiter16(int16_t u, int16_t rate, int16_t *y)
{
  int16_t q0;
  int16_t q1;

  q0 = (u << 4)  - *y;

  if (q0 > rate) {
    q0 = rate;
  } else {
    q1 = -rate;
    if (q0 < q1) {
      q0 = q1;
    }
  }

  *y = q0 + *y;
}

// ===========================================================
  /* multipleTapDet(int16_t u, uint32_t timeNow, MultipleTap *x)
  * This function detects multiple tap presses, such as double tapping, triple tapping, etc.
  * Inputs:       u = int16_t (input signal); timeNow = uint32_t (current time)  
  * Outputs:      x->b_multipleTap (get the output here)
  */
void multipleTapDet(int16_t u, uint32_t timeNow, MultipleTap *x)
{
  uint8_t 	b_timeout;
  uint8_t 	b_hyst;
  uint8_t 	b_pulse;
  uint8_t 	z_pulseCnt;
  uint8_t   z_pulseCntRst;
  uint32_t 	t_time; 

  // Detect hysteresis
  if (x->b_hysteresis) {
    b_hyst = (u > MULTIPLE_TAP_LO);
  } else {
    b_hyst = (u > MULTIPLE_TAP_HI);
  }

  // Detect pulse
  b_pulse = (b_hyst != x->b_hysteresis);

  // Save time when first pulse is detected
  if (b_hyst && b_pulse && (x->z_pulseCntPrev == 0)) {
    t_time = timeNow;
  } else {
    t_time = x->t_timePrev;
  }

  // Create timeout boolean
  b_timeout = (timeNow - t_time > MULTIPLE_TAP_TIMEOUT);

  // Create pulse counter
  if ((!b_hyst) && (x->z_pulseCntPrev == 0)) {
    z_pulseCnt = 0U;
  } else {
    z_pulseCnt = b_pulse;
  }

  // Reset counter if we detected complete tap presses OR there is a timeout
  if ((x->z_pulseCntPrev >= MULTIPLE_TAP_NR) || b_timeout) {
    z_pulseCntRst = 0U;
  } else {
    z_pulseCntRst = x->z_pulseCntPrev;
  }
  z_pulseCnt = z_pulseCnt + z_pulseCntRst;

  // Check if complete tap presses are detected AND no timeout
  if ((z_pulseCnt >= MULTIPLE_TAP_NR) && (!b_timeout)) {
    x->b_multipleTap = !x->b_multipleTap;	// Toggle output
  }

  // Update states
  x->z_pulseCntPrev = z_pulseCnt;
  x->b_hysteresis 	= b_hyst;
  x->t_timePrev 	  = t_time;
}

// ===========================================================

/** System Clock Configuration
*/
void SystemClock_Config(void) {
  RCC_OscInitTypeDef RCC_OscInitStruct;
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_PeriphCLKInitTypeDef PeriphClkInit;

  /**Initializes the CPU, AHB and APB busses clocks
    */
  RCC_OscInitStruct.OscillatorType      = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState            = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = 16;
  RCC_OscInitStruct.PLL.PLLState        = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource       = RCC_PLLSOURCE_HSI_DIV2;
  RCC_OscInitStruct.PLL.PLLMUL          = RCC_PLL_MUL16;
  HAL_RCC_OscConfig(&RCC_OscInitStruct);

  /**Initializes the CPU, AHB and APB busses clocks
    */
  RCC_ClkInitStruct.ClockType           = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource        = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider       = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider      = RCC_HCLK_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider      = RCC_HCLK_DIV1;

  HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2);

  PeriphClkInit.PeriphClockSelection    = RCC_PERIPHCLK_ADC;
  // PeriphClkInit.AdcClockSelection    = RCC_ADCPCLK2_DIV8;  // 8 MHz
  PeriphClkInit.AdcClockSelection       = RCC_ADCPCLK2_DIV4;  // 16 MHz
  HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit);

  /**Configure the Systick interrupt time
    */
  HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq() / 1000);

  /**Configure the Systick
    */
  HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);

  /* SysTick_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);
}