servo.c 12.3 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
/*
 * This file is part of the Micro Python project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2013, 2014 Damien P. George
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

Damien George's avatar
Damien George committed
27 28
#include <stdio.h>

29
#include STM32_HAL_H
Damien George's avatar
Damien George committed
30

31 32
#include "py/nlr.h"
#include "py/runtime.h"
33
#include "timer.h"
Damien George's avatar
Damien George committed
34 35
#include "servo.h"

36 37 38 39 40
/// \moduleref pyb
/// \class Servo - 3-wire hobby servo driver
///
/// Servo controls standard hobby servos with 3-wires (ground, power, signal).

Damien George's avatar
Damien George committed
41 42 43
// 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
44
// we use TIM5
Damien George's avatar
Damien George committed
45

46 47 48 49
#define PYB_SERVO_NUM (4)

typedef struct _pyb_servo_obj_t {
    mp_obj_base_t base;
50 51 52 53 54 55 56 57
    uint8_t servo_id;
    uint8_t pulse_min;          // units of 10us
    uint8_t pulse_max;          // units of 10us
    uint8_t pulse_centre;       // units of 10us
    uint8_t pulse_angle_90;     // units of 10us; pulse at 90 degrees, minus pulse_centre
    uint8_t pulse_speed_100;    // units of 10us; pulse at 100% forward speed, minus pulse_centre
    uint16_t pulse_cur;         // units of 10us
    uint16_t pulse_dest;        // units of 10us
58
    int16_t pulse_accum;
59
    uint16_t time_left;
60 61 62 63
} pyb_servo_obj_t;

STATIC pyb_servo_obj_t pyb_servo_obj[PYB_SERVO_NUM];

Damien George's avatar
Damien George committed
64
void servo_init(void) {
65
    timer_tim5_init();
66 67 68

    // reset servo objects
    for (int i = 0; i < PYB_SERVO_NUM; i++) {
69
        pyb_servo_obj[i].base.type = &pyb_servo_type;
70
        pyb_servo_obj[i].servo_id = i + 1;
71 72 73 74 75 76
        pyb_servo_obj[i].pulse_min = 64;
        pyb_servo_obj[i].pulse_max = 242;
        pyb_servo_obj[i].pulse_centre = 150;
        pyb_servo_obj[i].pulse_angle_90 = 97;
        pyb_servo_obj[i].pulse_speed_100 = 70;
        pyb_servo_obj[i].pulse_cur = 150;
77
        pyb_servo_obj[i].pulse_dest = 0;
78
        pyb_servo_obj[i].time_left = 0;
79 80 81 82 83 84 85 86
    }
}

void servo_timer_irq_callback(void) {
    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) {
87 88 89 90 91 92 93
            // clamp pulse to within min/max
            if (s->pulse_dest < s->pulse_min) {
                s->pulse_dest = s->pulse_min;
            } else if (s->pulse_dest > s->pulse_max) {
                s->pulse_dest = s->pulse_max;
            }
            // adjust cur to get closer to dest
94 95 96 97 98 99 100 101 102 103
            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;
            }
104
            // set the pulse width
105
            switch (s->servo_id) {
106 107 108 109
                case 1: TIM5->CCR1 = s->pulse_cur; break;
                case 2: TIM5->CCR2 = s->pulse_cur; break;
                case 3: TIM5->CCR3 = s->pulse_cur; break;
                case 4: TIM5->CCR4 = s->pulse_cur; break;
110 111 112 113
            }
        }
    }
    if (need_it) {
114
        __HAL_TIM_ENABLE_IT(&TIM5_Handle, TIM_IT_UPDATE);
115
    } else {
116
        __HAL_TIM_DISABLE_IT(&TIM5_Handle, TIM_IT_UPDATE);
117
    }
Damien George's avatar
Damien George committed
118 119
}

120
STATIC void servo_init_channel(pyb_servo_obj_t *s) {
Damien George's avatar
Damien George committed
121 122
    uint32_t pin;
    uint32_t channel;
123
    switch (s->servo_id) {
Damien George's avatar
Damien George committed
124 125 126 127 128 129 130 131 132 133 134 135 136
        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;
137
    GPIO_InitStructure.Alternate = GPIO_AF2_TIM5;
Damien George's avatar
Damien George committed
138 139 140 141 142
    HAL_GPIO_Init(GPIOA, &GPIO_InitStructure);

    // PWM mode configuration
    TIM_OC_InitTypeDef oc_init;
    oc_init.OCMode = TIM_OCMODE_PWM1;
143
    oc_init.Pulse = s->pulse_cur; // units of 10us
Damien George's avatar
Damien George committed
144 145
    oc_init.OCPolarity = TIM_OCPOLARITY_HIGH;
    oc_init.OCFastMode = TIM_OCFAST_DISABLE;
146
    HAL_TIM_PWM_ConfigChannel(&TIM5_Handle, &oc_init, channel);
Damien George's avatar
Damien George committed
147 148

    // start PWM
149
    HAL_TIM_PWM_Start(&TIM5_Handle, channel);
Damien George's avatar
Damien George committed
150 151 152 153 154 155 156 157 158 159 160
}

/******************************************************************************/
// 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) {
161 162 163 164
        case 1: TIM5->CCR1 = v; break;
        case 2: TIM5->CCR2 = v; break;
        case 3: TIM5->CCR3 = v; break;
        case 4: TIM5->CCR4 = v; break;
Damien George's avatar
Damien George committed
165 166 167 168 169 170 171 172 173
    }
    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);
174 175
    TIM5->ARR = pe;
    TIM5->CCR3 = pu;
Damien George's avatar
Damien George committed
176 177 178 179 180
    return mp_const_none;
}

MP_DEFINE_CONST_FUN_OBJ_2(pyb_pwm_set_obj, pyb_pwm_set);

181
STATIC void pyb_servo_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
Damien George's avatar
Damien George committed
182
    pyb_servo_obj_t *self = self_in;
183
    mp_printf(print, "<Servo %lu at %luus>", self->servo_id, 10 * self->pulse_cur);
Damien George's avatar
Damien George committed
184 185
}

186 187
/// \classmethod \constructor(id)
/// Create a servo object.  `id` is 1-4.
188
STATIC mp_obj_t pyb_servo_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
189
    // check arguments
Damien George's avatar
Damien George committed
190
    mp_arg_check_num(n_args, n_kw, 1, 1, false);
191 192

    // get servo number
193
    mp_int_t servo_id = mp_obj_get_int(args[0]) - 1;
194 195 196

    // check servo number
    if (!(0 <= servo_id && servo_id < PYB_SERVO_NUM)) {
197
        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "Servo %d does not exist", servo_id + 1));
198 199 200 201 202 203 204 205 206 207 208
    }

    // get and init servo object
    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;
}

209 210
/// \method pulse_width([value])
/// Get or set the pulse width in milliseconds.
211
STATIC mp_obj_t pyb_servo_pulse_width(mp_uint_t n_args, const mp_obj_t *args) {
212 213 214 215 216 217 218 219 220 221 222 223 224 225
    pyb_servo_obj_t *self = args[0];
    if (n_args == 1) {
        // get pulse width, in us
        return mp_obj_new_int(10 * self->pulse_cur);
    } else {
        // set pulse width, in us
        self->pulse_dest = mp_obj_get_int(args[1]) / 10;
        self->time_left = 0;
        servo_timer_irq_callback();
        return mp_const_none;
    }
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_servo_pulse_width_obj, 1, 2, pyb_servo_pulse_width);

226 227
/// \method calibration([pulse_min, pulse_max, pulse_centre, [pulse_angle_90, pulse_speed_100]])
/// Get or set the calibration of the servo timing.
228
// TODO should accept 1 arg, a 5-tuple of values to set
229
STATIC mp_obj_t pyb_servo_calibration(mp_uint_t n_args, const mp_obj_t *args) {
230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254
    pyb_servo_obj_t *self = args[0];
    if (n_args == 1) {
        // get calibration values
        mp_obj_t tuple[5];
        tuple[0] = mp_obj_new_int(10 * self->pulse_min);
        tuple[1] = mp_obj_new_int(10 * self->pulse_max);
        tuple[2] = mp_obj_new_int(10 * self->pulse_centre);
        tuple[3] = mp_obj_new_int(10 * (self->pulse_angle_90 + self->pulse_centre));
        tuple[4] = mp_obj_new_int(10 * (self->pulse_speed_100 + self->pulse_centre));
        return mp_obj_new_tuple(5, tuple);
    } else if (n_args >= 4) {
        // set min, max, centre
        self->pulse_min = mp_obj_get_int(args[1]) / 10;
        self->pulse_max = mp_obj_get_int(args[2]) / 10;
        self->pulse_centre = mp_obj_get_int(args[3]) / 10;
        if (n_args == 4) {
            return mp_const_none;
        } else if (n_args == 6) {
            self->pulse_angle_90 = mp_obj_get_int(args[4]) / 10 - self->pulse_centre;
            self->pulse_speed_100 = mp_obj_get_int(args[5]) / 10 - self->pulse_centre;
            return mp_const_none;
        }
    }

    // bad number of arguments
255
    nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "calibration expecting 1, 4 or 6 arguments, got %d", n_args));
256
}
257
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_servo_calibration_obj, 1, 6, pyb_servo_calibration);
258

259 260 261 262 263
/// \method angle([angle, time=0])
/// Get or set the angle of the servo.
///
///   - `angle` is the angle to move to in degrees.
///   - `time` is the number of milliseconds to take to get to the specified angle.
264
STATIC mp_obj_t pyb_servo_angle(mp_uint_t n_args, const mp_obj_t *args) {
265 266 267
    pyb_servo_obj_t *self = args[0];
    if (n_args == 1) {
        // get angle
268
        return mp_obj_new_int((self->pulse_cur - self->pulse_centre) * 90 / self->pulse_angle_90);
269
    } else {
270
#if MICROPY_PY_BUILTINS_FLOAT
271
        self->pulse_dest = self->pulse_centre + self->pulse_angle_90 * mp_obj_get_float(args[1]) / 90.0;
Damien George's avatar
Damien George committed
272
#else
273
        self->pulse_dest = self->pulse_centre + self->pulse_angle_90 * mp_obj_get_int(args[1]) / 90;
Damien George's avatar
Damien George committed
274
#endif
275 276 277 278 279 280 281 282 283 284
        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;
Damien George's avatar
Damien George committed
285 286
    }
}
287
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_servo_angle_obj, 1, 3, pyb_servo_angle);
Damien George's avatar
Damien George committed
288

289 290 291 292 293
/// \method speed([speed, time=0])
/// Get or set the speed of a continuous rotation servo.
///
///   - `speed` is the speed to move to change to, between -100 and 100.
///   - `time` is the number of milliseconds to take to get to the specified speed.
294
STATIC mp_obj_t pyb_servo_speed(mp_uint_t n_args, const mp_obj_t *args) {
295 296 297 298 299
    pyb_servo_obj_t *self = args[0];
    if (n_args == 1) {
        // get speed
        return mp_obj_new_int((self->pulse_cur - self->pulse_centre) * 100 / self->pulse_speed_100);
    } else {
300
#if MICROPY_PY_BUILTINS_FLOAT
301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319
        self->pulse_dest = self->pulse_centre + self->pulse_speed_100 * mp_obj_get_float(args[1]) / 100.0;
#else
        self->pulse_dest = self->pulse_centre + self->pulse_speed_100 * mp_obj_get_int(args[1]) / 100;
#endif
        if (n_args == 2) {
            // set speed immediately
            self->time_left = 0;
        } else {
            // set speed 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(pyb_servo_speed_obj, 1, 3, pyb_servo_speed);

320
STATIC const mp_map_elem_t pyb_servo_locals_dict_table[] = {
321
    { MP_OBJ_NEW_QSTR(MP_QSTR_pulse_width), (mp_obj_t)&pyb_servo_pulse_width_obj },
322
    { MP_OBJ_NEW_QSTR(MP_QSTR_calibration), (mp_obj_t)&pyb_servo_calibration_obj },
323
    { MP_OBJ_NEW_QSTR(MP_QSTR_angle), (mp_obj_t)&pyb_servo_angle_obj },
324
    { MP_OBJ_NEW_QSTR(MP_QSTR_speed), (mp_obj_t)&pyb_servo_speed_obj },
Damien George's avatar
Damien George committed
325 326
};

327 328
STATIC MP_DEFINE_CONST_DICT(pyb_servo_locals_dict, pyb_servo_locals_dict_table);

329
const mp_obj_type_t pyb_servo_type = {
Damien George's avatar
Damien George committed
330 331
    { &mp_type_type },
    .name = MP_QSTR_Servo,
332 333
    .print = pyb_servo_print,
    .make_new = pyb_servo_make_new,
334
    .locals_dict = (mp_obj_t)&pyb_servo_locals_dict,
Damien George's avatar
Damien George committed
335
};