flight/pios/stm32f4xx/pios_servo.c

   1 /**
   2  ******************************************************************************
   3  * @addtogroup PIOS PIOS Core hardware abstraction layer
   4  * @{
   5  * @addtogroup   PIOS_SERVO RC Servo Functions
   6  * @brief Code to do set RC servo output
   7  * @{
   8  *
   9  * @file       pios_servo.c
  10  * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2012.
  11  * @brief      RC Servo routines (STM32 dependent)
  12  * @see        The GNU Public License (GPL) Version 3
  13  *
  14  *****************************************************************************/
  15 /*
  16  * This program is free software; you can redistribute it and/or modify
  17  * it under the terms of the GNU General Public License as published by
  18  * the Free Software Foundation; either version 3 of the License, or
  19  * (at your option) any later version.
  20  *
  21  * This program is distributed in the hope that it will be useful, but
  22  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  23  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  24  * for more details.
  25  *
  26  * You should have received a copy of the GNU General Public License along
  27  * with this program; if not, write to the Free Software Foundation, Inc.,
  28  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  29  */
  30
  31 #include "pios.h"
  32
  33 #ifdef PIOS_INCLUDE_SERVO
  34
  35 #include "pios_servo_priv.h"
  36 #include "pios_tim_priv.h"
  37
  38 /* Private Function Prototypes */
  39
  40 static const struct pios_servo_cfg *servo_cfg;
  41
  42 // determine if the related timer will work in synchronous (or OneShot/OneShot125) One Pulse mode.
  43 static uint8_t pios_servo_bank_mode[PIOS_SERVO_BANKS] = { 0 };
  44 // used to skip updates when pulse length is higher than update cycle
  45 static uint16_t pios_servo_bank_next_update[PIOS_SERVO_BANKS] = { 0 };
  46 static uint16_t pios_servo_bank_max_pulse[PIOS_SERVO_BANKS] = { 0 };
  47 // timer associated to each bank
  48 static TIM_TypeDef *pios_servo_bank_timer[PIOS_SERVO_BANKS] = { 0 };
  49
  50 // index of bank used for each pin
  51 static uint8_t *pios_servo_pin_bank;
  52
  53 #define PIOS_SERVO_TIMER_CLOCK 1000000
  54 #define PIOS_SERVO_SAFE_MARGIN 50
  55 /**
  56  * Initialise Servos
  57  */
  58 int32_t PIOS_Servo_Init(const struct pios_servo_cfg *cfg)
  59 {
  60     uint32_t tim_id;
  61
  62     if (PIOS_TIM_InitChannels(&tim_id, cfg->channels, cfg->num_channels, NULL, 0)) {
  63         return -1;
  64     }
  65
  66     /* Store away the requested configuration */
  67     servo_cfg = cfg;
  68     pios_servo_pin_bank = pios_malloc(sizeof(uint8_t) * cfg->num_channels);
  69
  70     uint8_t bank = 0;
  71     for (uint8_t i = 0; (i < servo_cfg->num_channels); i++) {
  72         const struct pios_tim_channel *chan = &servo_cfg->channels[i];
  73         bool new = true;
  74         /* See if any previous channels use that same timer */
  75         for (uint8_t j = 0; (j < i) && new; j++) {
  76             new &= chan->timer != servo_cfg->channels[j].timer;
  77         }
  78
  79         if (new) {
  80             PIOS_Assert(bank < PIOS_SERVO_BANKS);
  81             for (uint8_t j = i; j < servo_cfg->num_channels; j++) {
  82                 if (servo_cfg->channels[j].timer == chan->timer) {
  83                     pios_servo_pin_bank[j] = bank;
  84                 }
  85             }
  86             pios_servo_bank_timer[bank] = chan->timer;
  87
  88             TIM_ARRPreloadConfig(chan->timer, ENABLE);
  89             TIM_CtrlPWMOutputs(chan->timer, ENABLE);
  90             TIM_Cmd(chan->timer, DISABLE);
  91
  92             bank++;
  93         }
  94
  95         /* Set up for output compare function */
  96         switch (chan->timer_chan) {
  97         case TIM_Channel_1:
  98             TIM_OC1Init(chan->timer, &servo_cfg->tim_oc_init);
  99             TIM_OC1PreloadConfig(chan->timer, TIM_OCPreload_Enable);
 100             break;
 101         case TIM_Channel_2:
 102             TIM_OC2Init(chan->timer, &servo_cfg->tim_oc_init);
 103             TIM_OC2PreloadConfig(chan->timer, TIM_OCPreload_Enable);
 104             break;
 105         case TIM_Channel_3:
 106             TIM_OC3Init(chan->timer, &servo_cfg->tim_oc_init);
 107             TIM_OC3PreloadConfig(chan->timer, TIM_OCPreload_Enable);
 108             break;
 109         case TIM_Channel_4:
 110             TIM_OC4Init(chan->timer, &servo_cfg->tim_oc_init);
 111             TIM_OC4PreloadConfig(chan->timer, TIM_OCPreload_Enable);
 112             break;
 113         }
 114     }
 115
 116     return 0;
 117 }
 118
 119 void PIOS_Servo_SetBankMode(uint8_t bank, uint8_t mode)
 120 {
 121     PIOS_Assert(bank < PIOS_SERVO_BANKS);
 122     pios_servo_bank_mode[bank] = mode;
 123
 124     if (pios_servo_bank_timer[bank]) {
 125         for (uint8_t i = 0; (i < servo_cfg->num_channels); i++) {
 126             if (pios_servo_pin_bank[i] == bank) {
 127                 const struct pios_tim_channel *chan = &servo_cfg->channels[i];
 128                 /* Set up for output compare function */
 129                 switch (chan->timer_chan) {
 130                 case TIM_Channel_1:
 131                     TIM_OC1PolarityConfig(chan->timer, TIM_OCPolarity_High);
 132                     break;
 133                 case TIM_Channel_2:
 134                     TIM_OC2PolarityConfig(chan->timer, TIM_OCPolarity_High);
 135                     break;
 136                 case TIM_Channel_3:
 137                     TIM_OC3PolarityConfig(chan->timer, TIM_OCPolarity_High);
 138                     break;
 139                 case TIM_Channel_4:
 140                     TIM_OC4PolarityConfig(chan->timer, TIM_OCPolarity_High);
 141                     break;
 142                 }
 143             }
 144         }
 145
 146         // Setup the timer accordingly
 147         TIM_SelectOnePulseMode(pios_servo_bank_timer[bank], TIM_OPMode_Repetitive);
 148         TIM_Cmd(pios_servo_bank_timer[bank], ENABLE);
 149     }
 150 }
 151
 152
 153 void PIOS_Servo_Update()
 154 {
 155     for (uint8_t i = 0; (i < PIOS_SERVO_BANKS); i++) {
 156         const TIM_TypeDef *timer = pios_servo_bank_timer[i];
 157         if (timer && pios_servo_bank_mode[i] == PIOS_SERVO_BANK_MODE_SINGLE_PULSE) {
 158             // a pulse to be generated is longer than cycle period. skip this update.
 159             if (TIM_GetCounter((TIM_TypeDef *)timer) > (uint32_t)(pios_servo_bank_next_update[i] + PIOS_SERVO_SAFE_MARGIN)) {
 160                 TIM_GenerateEvent((TIM_TypeDef *)timer, TIM_EventSource_Update);
 161                 pios_servo_bank_next_update[i] = pios_servo_bank_max_pulse[i];
 162             }
 163         }
 164         pios_servo_bank_max_pulse[i] = 0;
 165     }
 166     for (uint8_t i = 0; (i < servo_cfg->num_channels); i++) {
 167         uint8_t bank = pios_servo_pin_bank[i];
 168         uint8_t mode = pios_servo_bank_mode[bank];
 169         if (mode == PIOS_SERVO_BANK_MODE_SINGLE_PULSE) {
 170             /* Update the position */
 171             const struct pios_tim_channel *chan = &servo_cfg->channels[i];
 172
 173             switch (chan->timer_chan) {
 174             case TIM_Channel_1:
 175                 TIM_SetCompare1(chan->timer, 0);
 176                 break;
 177             case TIM_Channel_2:
 178                 TIM_SetCompare2(chan->timer, 0);
 179                 break;
 180             case TIM_Channel_3:
 181                 TIM_SetCompare3(chan->timer, 0);
 182                 break;
 183             case TIM_Channel_4:
 184                 TIM_SetCompare4(chan->timer, 0);
 185                 break;
 186             }
 187         }
 188     }
 189 }
 190 /**
 191  * Set the servo update rate (Max 500Hz)
 192  * \param[in] array of rates in Hz
 193  * \param[in] array of timer clocks in Hz
 194  * \param[in] maximum number of banks
 195  */
 196 void PIOS_Servo_SetHz(const uint16_t *speeds, const uint32_t *clock, uint8_t banks)
 197 {
 198     PIOS_Assert(banks <= PIOS_SERVO_BANKS);
 199     if (!servo_cfg) {
 200         return;
 201     }
 202
 203     TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure = servo_cfg->tim_base_init;
 204     TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
 205     TIM_TimeBaseStructure.TIM_CounterMode   = TIM_CounterMode_Up;
 206
 207     for (uint8_t i = 0; i < banks && i < PIOS_SERVO_BANKS; i++) {
 208         const TIM_TypeDef *timer = pios_servo_bank_timer[i];
 209         if (timer) {
 210             uint32_t new_clock = PIOS_SERVO_TIMER_CLOCK;
 211             if (clock[i]) {
 212                 new_clock = clock[i];
 213             }
 214             // Choose the correct prescaler value for the APB the timer is attached
 215             if (timer == TIM1 || timer == TIM8 || timer == TIM9 || timer == TIM10 || timer == TIM11) {
 216                 TIM_TimeBaseStructure.TIM_Prescaler = (PIOS_PERIPHERAL_APB2_CLOCK / new_clock) - 1;
 217             } else {
 218                 TIM_TimeBaseStructure.TIM_Prescaler = (PIOS_PERIPHERAL_APB1_CLOCK / new_clock) - 1;
 219             }
 220             TIM_TimeBaseStructure.TIM_Period = ((new_clock / speeds[i]) - 1);
 221             TIM_TimeBaseInit((TIM_TypeDef *)timer, &TIM_TimeBaseStructure);
 222         }
 223     }
 224 }
 225
 226 /**
 227  * Set servo position
 228  * \param[in] Servo Servo number (0-7)
 229  * \param[in] Position Servo position in microseconds
 230  */
 231 void PIOS_Servo_Set(uint8_t servo, uint16_t position)
 232 {
 233     /* Make sure servo exists */
 234     if (!servo_cfg || servo >= servo_cfg->num_channels) {
 235         return;
 236     }
 237
 238
 239     /* Update the position */
 240     const struct pios_tim_channel *chan = &servo_cfg->channels[servo];
 241     uint16_t val    = position;
 242     uint16_t margin = chan->timer->ARR / 50; // Leave 2% of period as margin to prevent overlaps
 243     if (val > (chan->timer->ARR - margin)) {
 244         val = chan->timer->ARR - margin;
 245     }
 246
 247     uint8_t bank = pios_servo_pin_bank[servo];
 248     if (pios_servo_bank_max_pulse[bank] < val) {
 249         pios_servo_bank_max_pulse[bank] = val;
 250     }
 251     switch (chan->timer_chan) {
 252     case TIM_Channel_1:
 253         TIM_SetCompare1(chan->timer, val);
 254         break;
 255     case TIM_Channel_2:
 256         TIM_SetCompare2(chan->timer, val);
 257         break;
 258     case TIM_Channel_3:
 259         TIM_SetCompare3(chan->timer, val);
 260         break;
 261     case TIM_Channel_4:
 262         TIM_SetCompare4(chan->timer, val);
 263         break;
 264     }
 265 }
 266
 267 uint8_t PIOS_Servo_GetPinBank(uint8_t pin)
 268 {
 269     if (pin < servo_cfg->num_channels) {
 270         return pios_servo_pin_bank[pin];
 271     } else {
 272         return 0;
 273     }
 274 }
 275
 276 #endif /* PIOS_INCLUDE_SERVO */