/**
******************************************************************************
* @addtogroup PIOS PIOS Core hardware abstraction layer
* @{
* @addtogroup PIOS_SERVO RC Servo Functions
* @brief Code to do set RC servo output
* @{
*
* @file pios_servo.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2012.
* @brief RC Servo routines (STM32 dependent)
* @see The GNU Public License (GPL) Version 3
*
*****************************************************************************/
/*
* 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, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "pios.h"
#ifdef PIOS_INCLUDE_SERVO
#include "pios_servo_priv.h"
#include "pios_tim_priv.h"
/* Private Function Prototypes */
static const struct pios_servo_cfg *servo_cfg;
// determine if the related timer will work in synchronous (or OneShot/OneShot125) One Pulse mode.
static uint8_t pios_servo_bank_mode[PIOS_SERVO_BANKS] = { 0 };
// used to skip updates when pulse length is higher than update cycle
static uint16_t pios_servo_bank_next_update[PIOS_SERVO_BANKS] = { 0 };
static uint16_t pios_servo_bank_max_pulse[PIOS_SERVO_BANKS] = { 0 };
// timer associated to each bank
static TIM_TypeDef *pios_servo_bank_timer[PIOS_SERVO_BANKS] = { 0 };
// index of bank used for each pin
static uint8_t *pios_servo_pin_bank;
#define PIOS_SERVO_TIMER_CLOCK 1000000
#define PIOS_SERVO_SAFE_MARGIN 50
/**
* Initialise Servos
*/
int32_t PIOS_Servo_Init(const struct pios_servo_cfg *cfg)
{
uint32_t tim_id;
if (PIOS_TIM_InitChannels(&tim_id, cfg->channels, cfg->num_channels, NULL, 0)) {
return -1;
}
/* Store away the requested configuration */
servo_cfg = cfg;
pios_servo_pin_bank = pios_malloc(sizeof(uint8_t) * cfg->num_channels);
uint8_t bank = 0;
for (uint8_t i = 0; (i < servo_cfg->num_channels); i++) {
const struct pios_tim_channel *chan = &servo_cfg->channels[i];
bool new = true;
/* See if any previous channels use that same timer */
for (uint8_t j = 0; (j < i) && new; j++) {
new &= chan->timer != servo_cfg->channels[j].timer;
}
if (new) {
PIOS_Assert(bank < PIOS_SERVO_BANKS);
for (uint8_t j = i; j < servo_cfg->num_channels; j++) {
if (servo_cfg->channels[j].timer == chan->timer) {
pios_servo_pin_bank[j] = bank;
}
}
pios_servo_bank_timer[bank] = chan->timer;
TIM_ARRPreloadConfig(chan->timer, ENABLE);
TIM_CtrlPWMOutputs(chan->timer, ENABLE);
TIM_Cmd(chan->timer, DISABLE);
bank++;
}
/* Set up for output compare function */
switch (chan->timer_chan) {
case TIM_Channel_1:
TIM_OC1Init(chan->timer, &servo_cfg->tim_oc_init);
TIM_OC1PreloadConfig(chan->timer, TIM_OCPreload_Enable);
break;
case TIM_Channel_2:
TIM_OC2Init(chan->timer, &servo_cfg->tim_oc_init);
TIM_OC2PreloadConfig(chan->timer, TIM_OCPreload_Enable);
break;
case TIM_Channel_3:
TIM_OC3Init(chan->timer, &servo_cfg->tim_oc_init);
TIM_OC3PreloadConfig(chan->timer, TIM_OCPreload_Enable);
break;
case TIM_Channel_4:
TIM_OC4Init(chan->timer, &servo_cfg->tim_oc_init);
TIM_OC4PreloadConfig(chan->timer, TIM_OCPreload_Enable);
break;
}
}
return 0;
}
void PIOS_Servo_SetBankMode(uint8_t bank, uint8_t mode)
{
PIOS_Assert(bank < PIOS_SERVO_BANKS);
pios_servo_bank_mode[bank] = mode;
if (pios_servo_bank_timer[bank]) {
for (uint8_t i = 0; (i < servo_cfg->num_channels); i++) {
if (pios_servo_pin_bank[i] == bank) {
const struct pios_tim_channel *chan = &servo_cfg->channels[i];
/* Set up for output compare function */
switch (chan->timer_chan) {
case TIM_Channel_1:
TIM_OC1PolarityConfig(chan->timer, TIM_OCPolarity_High);
break;
case TIM_Channel_2:
TIM_OC2PolarityConfig(chan->timer, TIM_OCPolarity_High);
break;
case TIM_Channel_3:
TIM_OC3PolarityConfig(chan->timer, TIM_OCPolarity_High);
break;
case TIM_Channel_4:
TIM_OC4PolarityConfig(chan->timer, TIM_OCPolarity_High);
break;
}
}
}
// Setup the timer accordingly
TIM_SelectOnePulseMode(pios_servo_bank_timer[bank], TIM_OPMode_Repetitive);
TIM_Cmd(pios_servo_bank_timer[bank], ENABLE);
}
}
void PIOS_Servo_Update()
{
for (uint8_t i = 0; (i < PIOS_SERVO_BANKS); i++) {
const TIM_TypeDef *timer = pios_servo_bank_timer[i];
if (timer && pios_servo_bank_mode[i] == PIOS_SERVO_BANK_MODE_SINGLE_PULSE) {
// a pulse to be generated is longer than cycle period. skip this update.
if (TIM_GetCounter((TIM_TypeDef *)timer) > (uint32_t)(pios_servo_bank_next_update[i] + PIOS_SERVO_SAFE_MARGIN)) {
TIM_GenerateEvent((TIM_TypeDef *)timer, TIM_EventSource_Update);
pios_servo_bank_next_update[i] = pios_servo_bank_max_pulse[i];
}
}
pios_servo_bank_max_pulse[i] = 0;
}
for (uint8_t i = 0; (i < servo_cfg->num_channels); i++) {
uint8_t bank = pios_servo_pin_bank[i];
uint8_t mode = pios_servo_bank_mode[bank];
if (mode == PIOS_SERVO_BANK_MODE_SINGLE_PULSE) {
/* Update the position */
const struct pios_tim_channel *chan = &servo_cfg->channels[i];
switch (chan->timer_chan) {
case TIM_Channel_1:
TIM_SetCompare1(chan->timer, 0);
break;
case TIM_Channel_2:
TIM_SetCompare2(chan->timer, 0);
break;
case TIM_Channel_3:
TIM_SetCompare3(chan->timer, 0);
break;
case TIM_Channel_4:
TIM_SetCompare4(chan->timer, 0);
break;
}
}
}
}
/**
* Set the servo update rate (Max 500Hz)
* \param[in] array of rates in Hz
* \param[in] array of timer clocks in Hz
* \param[in] maximum number of banks
*/
void PIOS_Servo_SetHz(const uint16_t *speeds, const uint32_t *clock, uint8_t banks)
{
PIOS_Assert(banks <= PIOS_SERVO_BANKS);
if (!servo_cfg) {
return;
}
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure = servo_cfg->tim_base_init;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
for (uint8_t i = 0; i < banks && i < PIOS_SERVO_BANKS; i++) {
const TIM_TypeDef *timer = pios_servo_bank_timer[i];
if (timer) {
uint32_t new_clock = PIOS_SERVO_TIMER_CLOCK;
if (clock[i]) {
new_clock = clock[i];
}
// Choose the correct prescaler value for the APB the timer is attached
if (timer == TIM1 || timer == TIM8 || timer == TIM9 || timer == TIM10 || timer == TIM11) {
TIM_TimeBaseStructure.TIM_Prescaler = (PIOS_PERIPHERAL_APB2_CLOCK / new_clock) - 1;
} else {
TIM_TimeBaseStructure.TIM_Prescaler = (PIOS_PERIPHERAL_APB1_CLOCK / new_clock) - 1;
}
TIM_TimeBaseStructure.TIM_Period = ((new_clock / speeds[i]) - 1);
TIM_TimeBaseInit((TIM_TypeDef *)timer, &TIM_TimeBaseStructure);
}
}
}
/**
* Set servo position
* \param[in] Servo Servo number (0-7)
* \param[in] Position Servo position in microseconds
*/
void PIOS_Servo_Set(uint8_t servo, uint16_t position)
{
/* Make sure servo exists */
if (!servo_cfg || servo >= servo_cfg->num_channels) {
return;
}
/* Update the position */
const struct pios_tim_channel *chan = &servo_cfg->channels[servo];
uint16_t val = position;
uint16_t margin = chan->timer->ARR / 50; // Leave 2% of period as margin to prevent overlaps
if (val > (chan->timer->ARR - margin)) {
val = chan->timer->ARR - margin;
}
uint8_t bank = pios_servo_pin_bank[servo];
if (pios_servo_bank_max_pulse[bank] < val) {
pios_servo_bank_max_pulse[bank] = val;
}
switch (chan->timer_chan) {
case TIM_Channel_1:
TIM_SetCompare1(chan->timer, val);
break;
case TIM_Channel_2:
TIM_SetCompare2(chan->timer, val);
break;
case TIM_Channel_3:
TIM_SetCompare3(chan->timer, val);
break;
case TIM_Channel_4:
TIM_SetCompare4(chan->timer, val);
break;
}
}
uint8_t PIOS_Servo_GetPinBank(uint8_t pin)
{
if (pin < servo_cfg->num_channels) {
return pios_servo_pin_bank[pin];
} else {
return 0;
}
}
#endif /* PIOS_INCLUDE_SERVO */