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
29
30
#include <stdio.h>

#include "stm32f4xx_hal.h"

31
#include "mpconfig.h"
32
#include "nlr.h"
Damien George's avatar
Damien George committed
33
34
35
#include "misc.h"
#include "qstr.h"
#include "obj.h"
36
#include "runtime.h"
37
#include "timer.h"
Damien George's avatar
Damien George committed
38
39
#include "servo.h"

40
41
42
43
44
/// \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
45
46
47
// 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
48
// we use TIM5
Damien George's avatar
Damien George committed
49

50
51
52
53
#define PYB_SERVO_NUM (4)

typedef struct _pyb_servo_obj_t {
    mp_obj_base_t base;
54
55
56
57
58
59
60
61
    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
62
    int16_t pulse_accum;
63
    uint16_t time_left;
64
65
66
67
} pyb_servo_obj_t;

STATIC pyb_servo_obj_t pyb_servo_obj[PYB_SERVO_NUM];

Damien George's avatar
Damien George committed
68
void servo_init(void) {
69
    timer_tim5_init();
70
71
72

    // reset servo objects
    for (int i = 0; i < PYB_SERVO_NUM; i++) {
73
        pyb_servo_obj[i].base.type = &pyb_servo_type;
74
        pyb_servo_obj[i].servo_id = i + 1;
75
76
77
78
79
80
        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;
81
        pyb_servo_obj[i].pulse_dest = 0;
82
        pyb_servo_obj[i].time_left = 0;
83
84
85
86
87
88
89
90
    }
}

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) {
91
92
93
94
95
96
97
            // 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
98
99
100
101
102
103
104
105
106
107
            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;
            }
108
            // set the pulse width
109
            switch (s->servo_id) {
110
111
112
113
                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;
114
115
116
117
            }
        }
    }
    if (need_it) {
118
        __HAL_TIM_ENABLE_IT(&TIM5_Handle, TIM_IT_UPDATE);
119
    } else {
120
        __HAL_TIM_DISABLE_IT(&TIM5_Handle, TIM_IT_UPDATE);
121
    }
Damien George's avatar
Damien George committed
122
123
}

124
STATIC void servo_init_channel(pyb_servo_obj_t *s) {
Damien George's avatar
Damien George committed
125
126
    uint32_t pin;
    uint32_t channel;
127
    switch (s->servo_id) {
Damien George's avatar
Damien George committed
128
129
130
131
132
133
134
135
136
137
138
139
140
        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;
141
    GPIO_InitStructure.Alternate = GPIO_AF2_TIM5;
Damien George's avatar
Damien George committed
142
143
144
145
146
    HAL_GPIO_Init(GPIOA, &GPIO_InitStructure);

    // PWM mode configuration
    TIM_OC_InitTypeDef oc_init;
    oc_init.OCMode = TIM_OCMODE_PWM1;
147
    oc_init.Pulse = s->pulse_cur; // units of 10us
Damien George's avatar
Damien George committed
148
149
    oc_init.OCPolarity = TIM_OCPOLARITY_HIGH;
    oc_init.OCFastMode = TIM_OCFAST_DISABLE;
150
    HAL_TIM_PWM_ConfigChannel(&TIM5_Handle, &oc_init, channel);
Damien George's avatar
Damien George committed
151
152

    // start PWM
153
    HAL_TIM_PWM_Start(&TIM5_Handle, channel);
Damien George's avatar
Damien George committed
154
155
156
157
158
159
160
161
162
163
164
}

/******************************************************************************/
// 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) {
165
166
167
168
        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
169
170
171
172
173
174
175
176
177
    }
    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);
178
179
    TIM5->ARR = pe;
    TIM5->CCR3 = pu;
Damien George's avatar
Damien George committed
180
181
182
183
184
    return mp_const_none;
}

MP_DEFINE_CONST_FUN_OBJ_2(pyb_pwm_set_obj, pyb_pwm_set);

185
STATIC void pyb_servo_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
Damien George's avatar
Damien George committed
186
    pyb_servo_obj_t *self = self_in;
187
    print(env, "<Servo %lu at %luus>", self->servo_id, 10 * self->pulse_cur);
Damien George's avatar
Damien George committed
188
189
}

190
191
/// \classmethod \constructor(id)
/// Create a servo object.  `id` is 1-4.
192
193
STATIC mp_obj_t pyb_servo_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
    // check arguments
Damien George's avatar
Damien George committed
194
    mp_arg_check_num(n_args, n_kw, 1, 1, false);
195
196
197
198
199
200

    // get servo number
    machine_int_t servo_id = mp_obj_get_int(args[0]) - 1;

    // check servo number
    if (!(0 <= servo_id && servo_id < PYB_SERVO_NUM)) {
201
        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "Servo %d does not exist", servo_id + 1));
202
203
204
205
206
207
208
209
210
211
212
    }

    // 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;
}

213
214
/// \method pulse_width([value])
/// Get or set the pulse width in milliseconds.
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
STATIC mp_obj_t pyb_servo_pulse_width(uint n_args, const mp_obj_t *args) {
    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);

230
231
/// \method calibration([pulse_min, pulse_max, pulse_centre, [pulse_angle_90, pulse_speed_100]])
/// Get or set the calibration of the servo timing.
232
// TODO should accept 1 arg, a 5-tuple of values to set
233
STATIC mp_obj_t pyb_servo_calibration(uint n_args, const mp_obj_t *args) {
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
    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
259
    nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "calibration expecting 1, 4 or 6 arguments, got %d", n_args));
260
}
261
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_servo_calibration_obj, 1, 6, pyb_servo_calibration);
262

263
264
265
266
267
/// \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.
268
STATIC mp_obj_t pyb_servo_angle(uint n_args, const mp_obj_t *args) {
269
270
271
    pyb_servo_obj_t *self = args[0];
    if (n_args == 1) {
        // get angle
272
        return mp_obj_new_int((self->pulse_cur - self->pulse_centre) * 90 / self->pulse_angle_90);
273
    } else {
Damien George's avatar
Damien George committed
274
#if MICROPY_ENABLE_FLOAT
275
        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
276
#else
277
        self->pulse_dest = self->pulse_centre + self->pulse_angle_90 * mp_obj_get_int(args[1]) / 90;
Damien George's avatar
Damien George committed
278
#endif
279
280
281
282
283
284
285
286
287
288
        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
289
290
    }
}
291
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_servo_angle_obj, 1, 3, pyb_servo_angle);
Damien George's avatar
Damien George committed
292

293
294
295
296
297
/// \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.
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
STATIC mp_obj_t pyb_servo_speed(uint n_args, const mp_obj_t *args) {
    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 {
#if MICROPY_ENABLE_FLOAT
        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);

324
STATIC const mp_map_elem_t pyb_servo_locals_dict_table[] = {
325
    { MP_OBJ_NEW_QSTR(MP_QSTR_pulse_width), (mp_obj_t)&pyb_servo_pulse_width_obj },
326
    { MP_OBJ_NEW_QSTR(MP_QSTR_calibration), (mp_obj_t)&pyb_servo_calibration_obj },
327
    { MP_OBJ_NEW_QSTR(MP_QSTR_angle), (mp_obj_t)&pyb_servo_angle_obj },
328
    { MP_OBJ_NEW_QSTR(MP_QSTR_speed), (mp_obj_t)&pyb_servo_speed_obj },
Damien George's avatar
Damien George committed
329
330
};

331
332
STATIC MP_DEFINE_CONST_DICT(pyb_servo_locals_dict, pyb_servo_locals_dict_table);

333
const mp_obj_type_t pyb_servo_type = {
Damien George's avatar
Damien George committed
334
335
    { &mp_type_type },
    .name = MP_QSTR_Servo,
336
337
    .print = pyb_servo_print,
    .make_new = pyb_servo_make_new,
338
    .locals_dict = (mp_obj_t)&pyb_servo_locals_dict,
Damien George's avatar
Damien George committed
339
};