UART with sideboards works + major refactoring

► the mainboard can now send and receive Serial data from the sideboards
► heavy refactored the `main.c`. It was becoming too large to manage... Therefore, `util.c` and `util.h` was created
► added new functionality for `VARIANT_HOVERCAR` and variants with `CONTROL_ADC` in general:
- ADC limits auto-calibration mode (long press of the power button) - calibration will not be lost at power-off
- Max Current and Max Speed adjustment mode (long press followed by a short press of the power button) - calibration will not be lost at power-off
- added one sideboard functionality:
         - LEDs are used to display battery level,  Motor Enable, Errors, Reverse driving, Braking.
         - Photo sensors are used as push buttons: One for changing Control Mode, One for Activating/Deactivating the Field Weakening on the fly

Inc/util.h

@@ -0,0 +1,96 @@
+/**
+  * This file is part of the hoverboard-firmware-hack project.
+  *
+  * Copyright (C) 2020-2021 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/>.
+*/
+
+// Define to prevent recursive inclusion
+#ifndef UTIL_H
+#define UTIL_H
+
+#include <stdint.h>
+
+#if defined(CONTROL_SERIAL_USART2) || defined(CONTROL_SERIAL_USART3)
+  #ifdef CONTROL_IBUS    
+    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
+#endif
+#if defined(SIDEBOARD_SERIAL_USART2) || defined(SIDEBOARD_SERIAL_USART3)
+    typedef struct{
+      uint16_t	start;
+      int16_t  	roll;
+      int16_t  	pitch;
+      int16_t  	yaw;
+      uint16_t  sensors;
+      uint16_t 	checksum;
+    } SerialSideboard;
+#endif
+
+// Initialization Functions
+void BLDC_Init(void);
+void Input_Lim_Init(void);
+void Input_Init(void);
+
+// General Functions
+void poweronMelody(void);
+void shortBeep(uint8_t freq);
+void shortBeepMany(uint8_t cnt);
+void longBeep(uint8_t freq);
+void calcAvgSpeed(void);
+void adcCalibLim(void);
+void updateCurSpdLim(void);
+void saveConfig(void);
+
+// Poweroff Functions
+void poweroff(void);
+void poweroffPressCheck(void);
+
+// Read Command Function
+void readCommand(void);
+
+// Sideboard functions
+void sideboardLeds(uint8_t *leds);
+void sideboardSensors(uint8_t sensors);
+
+// Filtering Functions
+void filtLowPass32(int32_t u, uint16_t coef, int32_t *y);
+void rateLimiter16(int16_t u, int16_t rate, int16_t *y);
+void mixerFcn(int16_t rtu_speed, int16_t rtu_steer, int16_t *rty_speedR, int16_t *rty_speedL);
+
+// Multiple Tap Function
+typedef struct {
+  uint32_t 	t_timePrev;
+  uint8_t 	z_pulseCntPrev;
+  uint8_t 	b_hysteresis;
+  uint8_t 	b_multipleTap;
+} MultipleTap;
+void multipleTapDet(int16_t u, uint32_t timeNow, MultipleTap *x);
+
+#endif
+