circuitpython/stmhal/servo.c
2014-03-22 18:34:16 +00:00

213 lines
6.5 KiB
C

#include <stdio.h>
#include "stm32f4xx_hal.h"
#include "nlr.h"
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "servo.h"
// this servo driver uses hardware PWM to drive servos on PA0, PA1, PA2, PA3 = X1, X2, X3, X4
// TIM2 and TIM5 have CH1, CH2, CH3, CH4 on PA0-PA3 respectively
// they are both 32-bit counters with 16-bit prescaler
// we use TIM2
#define PYB_SERVO_NUM (4)
typedef struct _pyb_servo_obj_t {
mp_obj_base_t base;
uint16_t servo_id;
uint16_t time_left;
int16_t pulse_accum;
uint16_t pulse_cur;
uint16_t pulse_dest;
} pyb_servo_obj_t;
STATIC const mp_obj_type_t servo_obj_type;
STATIC pyb_servo_obj_t pyb_servo_obj[PYB_SERVO_NUM];
TIM_HandleTypeDef servo_TIM2_Handle;
void servo_init(void) {
// TIM2 clock enable
__TIM2_CLK_ENABLE();
// set up and enable interrupt
HAL_NVIC_SetPriority(TIM2_IRQn, 6, 0);
HAL_NVIC_EnableIRQ(TIM2_IRQn);
// PWM clock configuration
servo_TIM2_Handle.Instance = TIM2;
servo_TIM2_Handle.Init.Period = 2000; // timer cycles at 50Hz
servo_TIM2_Handle.Init.Prescaler = ((SystemCoreClock / 2) / 100000) - 1; // timer runs at 100kHz
servo_TIM2_Handle.Init.ClockDivision = 0;
servo_TIM2_Handle.Init.CounterMode = TIM_COUNTERMODE_UP;
HAL_TIM_PWM_Init(&servo_TIM2_Handle);
// reset servo objects
for (int i = 0; i < PYB_SERVO_NUM; i++) {
pyb_servo_obj[i].base.type = &servo_obj_type;
pyb_servo_obj[i].servo_id = i + 1;
pyb_servo_obj[i].time_left = 0;
pyb_servo_obj[i].pulse_cur = 150; // units of 10us
pyb_servo_obj[i].pulse_dest = 0;
}
}
#include "led.h"
void servo_timer_irq_callback(void) {
led_toggle(1);
bool need_it = false;
for (int i = 0; i < PYB_SERVO_NUM; i++) {
pyb_servo_obj_t *s = &pyb_servo_obj[i];
if (s->pulse_cur != s->pulse_dest) {
if (s->time_left <= 1) {
s->pulse_cur = s->pulse_dest;
s->time_left = 0;
} else {
s->pulse_accum += s->pulse_dest - s->pulse_cur;
s->pulse_cur += s->pulse_accum / s->time_left;
s->pulse_accum %= s->time_left;
s->time_left--;
need_it = true;
}
switch (s->servo_id) {
case 1: TIM2->CCR1 = s->pulse_cur; break;
case 2: TIM2->CCR2 = s->pulse_cur; break;
case 3: TIM2->CCR3 = s->pulse_cur; break;
case 4: TIM2->CCR4 = s->pulse_cur; break;
}
}
}
if (need_it) {
__HAL_TIM_ENABLE_IT(&servo_TIM2_Handle, TIM_IT_UPDATE);
} else {
__HAL_TIM_DISABLE_IT(&servo_TIM2_Handle, TIM_IT_UPDATE);
}
}
STATIC void servo_init_channel(pyb_servo_obj_t *s) {
uint32_t pin;
uint32_t channel;
switch (s->servo_id) {
case 1: pin = GPIO_PIN_0; channel = TIM_CHANNEL_1; break;
case 2: pin = GPIO_PIN_1; channel = TIM_CHANNEL_2; break;
case 3: pin = GPIO_PIN_2; channel = TIM_CHANNEL_3; break;
case 4: pin = GPIO_PIN_3; channel = TIM_CHANNEL_4; break;
default: return;
}
// GPIO configuration
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.Pin = pin;
GPIO_InitStructure.Mode = GPIO_MODE_AF_PP;
GPIO_InitStructure.Speed = GPIO_SPEED_FAST;
GPIO_InitStructure.Pull = GPIO_NOPULL;
GPIO_InitStructure.Alternate = GPIO_AF1_TIM2;
HAL_GPIO_Init(GPIOA, &GPIO_InitStructure);
// PWM mode configuration
TIM_OC_InitTypeDef oc_init;
oc_init.OCMode = TIM_OCMODE_PWM1;
oc_init.Pulse = s->pulse_cur; // units of 10us
oc_init.OCPolarity = TIM_OCPOLARITY_HIGH;
oc_init.OCFastMode = TIM_OCFAST_DISABLE;
HAL_TIM_PWM_ConfigChannel(&servo_TIM2_Handle, &oc_init, channel);
// start PWM
HAL_TIM_PWM_Start(&servo_TIM2_Handle, channel);
}
/******************************************************************************/
// Micro Python bindings
STATIC mp_obj_t pyb_servo_set(mp_obj_t port, mp_obj_t value) {
int p = mp_obj_get_int(port);
int v = mp_obj_get_int(value);
if (v < 50) { v = 50; }
if (v > 250) { v = 250; }
switch (p) {
case 1: TIM2->CCR1 = v; break;
case 2: TIM2->CCR2 = v; break;
case 3: TIM2->CCR3 = v; break;
case 4: TIM2->CCR4 = v; break;
}
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_2(pyb_servo_set_obj, pyb_servo_set);
STATIC mp_obj_t pyb_pwm_set(mp_obj_t period, mp_obj_t pulse) {
int pe = mp_obj_get_int(period);
int pu = mp_obj_get_int(pulse);
TIM2->ARR = pe;
TIM2->CCR3 = pu;
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_2(pyb_pwm_set_obj, pyb_pwm_set);
STATIC void servo_obj_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
pyb_servo_obj_t *self = self_in;
print(env, "<Servo %lu at %lu>", self->servo_id, self->pulse_cur);
}
STATIC mp_obj_t servo_obj_angle(uint n_args, const mp_obj_t *args) {
pyb_servo_obj_t *self = args[0];
if (n_args == 1) {
// get angle
return mp_obj_new_int((self->pulse_cur - 152) * 90 / 85);
} else {
#if MICROPY_ENABLE_FLOAT
machine_int_t v = 152 + 85.0 * mp_obj_get_float(args[1]) / 90.0;
#else
machine_int_t v = 152 + 85 * mp_obj_get_int(args[1]) / 90;
#endif
if (v < 65) { v = 65; }
if (v > 210) { v = 210; }
self->pulse_dest = v;
if (n_args == 2) {
// set angle immediately
self->time_left = 0;
} else {
// set angle over a given time (given in milli seconds)
self->time_left = mp_obj_get_int(args[2]) / 20;
self->pulse_accum = 0;
}
servo_timer_irq_callback();
return mp_const_none;
}
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(servo_obj_angle_obj, 1, 3, servo_obj_angle);
STATIC const mp_method_t servo_methods[] = {
{ "angle", &servo_obj_angle_obj },
{ NULL, NULL },
};
STATIC const mp_obj_type_t servo_obj_type = {
{ &mp_type_type },
.name = MP_QSTR_Servo,
.print = servo_obj_print,
.methods = servo_methods,
};
STATIC mp_obj_t pyb_Servo(mp_obj_t servo_id_o) {
machine_int_t servo_id = mp_obj_get_int(servo_id_o) - 1;
if (0 <= servo_id && servo_id < PYB_SERVO_NUM) {
pyb_servo_obj_t *s = &pyb_servo_obj[servo_id];
s->pulse_dest = s->pulse_cur;
s->time_left = 0;
servo_init_channel(s);
return s;
} else {
nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "Servo %d does not exist", servo_id));
}
}
MP_DEFINE_CONST_FUN_OBJ_1(pyb_Servo_obj, pyb_Servo);