servo.c 10.2 KB
Newer Older
Damien George's avatar
Damien George committed
1
2
3
4
#include <stdio.h>

#include "stm32f4xx_hal.h"

5
#include "nlr.h"
Damien George's avatar
Damien George committed
6
7
8
9
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
10
#include "runtime.h"
11
#include "timer.h"
Damien George's avatar
Damien George committed
12
13
14
15
16
#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
17
// we use TIM5
Damien George's avatar
Damien George committed
18

19
20
21
22
#define PYB_SERVO_NUM (4)

typedef struct _pyb_servo_obj_t {
    mp_obj_base_t base;
23
24
25
26
27
28
29
30
    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
31
    int16_t pulse_accum;
32
    uint16_t time_left;
33
34
35
36
} pyb_servo_obj_t;

STATIC pyb_servo_obj_t pyb_servo_obj[PYB_SERVO_NUM];

Damien George's avatar
Damien George committed
37
void servo_init(void) {
38
    timer_tim5_init();
39
40
41

    // reset servo objects
    for (int i = 0; i < PYB_SERVO_NUM; i++) {
42
        pyb_servo_obj[i].base.type = &pyb_servo_type;
43
        pyb_servo_obj[i].servo_id = i + 1;
44
45
46
47
48
49
        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;
50
        pyb_servo_obj[i].pulse_dest = 0;
51
        pyb_servo_obj[i].time_left = 0;
52
53
54
55
56
57
58
59
    }
}

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) {
60
61
62
63
64
65
66
            // 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
67
68
69
70
71
72
73
74
75
76
            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;
            }
77
            // set the pulse width
78
            switch (s->servo_id) {
79
80
81
82
                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;
83
84
85
86
            }
        }
    }
    if (need_it) {
87
        __HAL_TIM_ENABLE_IT(&TIM5_Handle, TIM_IT_UPDATE);
88
    } else {
89
        __HAL_TIM_DISABLE_IT(&TIM5_Handle, TIM_IT_UPDATE);
90
    }
Damien George's avatar
Damien George committed
91
92
}

93
STATIC void servo_init_channel(pyb_servo_obj_t *s) {
Damien George's avatar
Damien George committed
94
95
    uint32_t pin;
    uint32_t channel;
96
    switch (s->servo_id) {
Damien George's avatar
Damien George committed
97
98
99
100
101
102
103
104
105
106
107
108
109
        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;
110
    GPIO_InitStructure.Alternate = GPIO_AF2_TIM5;
Damien George's avatar
Damien George committed
111
112
113
114
115
    HAL_GPIO_Init(GPIOA, &GPIO_InitStructure);

    // PWM mode configuration
    TIM_OC_InitTypeDef oc_init;
    oc_init.OCMode = TIM_OCMODE_PWM1;
116
    oc_init.Pulse = s->pulse_cur; // units of 10us
Damien George's avatar
Damien George committed
117
118
    oc_init.OCPolarity = TIM_OCPOLARITY_HIGH;
    oc_init.OCFastMode = TIM_OCFAST_DISABLE;
119
    HAL_TIM_PWM_ConfigChannel(&TIM5_Handle, &oc_init, channel);
Damien George's avatar
Damien George committed
120
121

    // start PWM
122
    HAL_TIM_PWM_Start(&TIM5_Handle, channel);
Damien George's avatar
Damien George committed
123
124
125
126
127
128
129
130
131
132
133
}

/******************************************************************************/
// 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) {
134
135
136
137
        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
138
139
140
141
142
143
144
145
146
    }
    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);
147
148
    TIM5->ARR = pe;
    TIM5->CCR3 = pu;
Damien George's avatar
Damien George committed
149
150
151
152
153
    return mp_const_none;
}

MP_DEFINE_CONST_FUN_OBJ_2(pyb_pwm_set_obj, pyb_pwm_set);

154
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
155
    pyb_servo_obj_t *self = self_in;
156
    print(env, "<Servo %lu at %luus>", self->servo_id, 10 * self->pulse_cur);
Damien George's avatar
Damien George committed
157
158
}

159
160
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
161
    mp_check_nargs(n_args, 1, 1, n_kw, false);
162
163
164
165
166
167

    // 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)) {
168
        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "Servo %d does not exist", servo_id + 1));
169
170
171
172
173
174
175
176
177
178
179
    }

    // 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;
}

180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
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);

STATIC mp_obj_t pyb_servo_calibrate(uint n_args, const mp_obj_t *args) {
    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
    nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "calibrate expecting 1, 4 or 6 arguments, got %d", n_args));
}

STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_servo_calibrate_obj, 1, 6, pyb_servo_calibrate);

227
STATIC mp_obj_t pyb_servo_angle(uint n_args, const mp_obj_t *args) {
228
229
230
    pyb_servo_obj_t *self = args[0];
    if (n_args == 1) {
        // get angle
231
        return mp_obj_new_int((self->pulse_cur - self->pulse_centre) * 90 / self->pulse_angle_90);
232
    } else {
Damien George's avatar
Damien George committed
233
#if MICROPY_ENABLE_FLOAT
234
        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
235
#else
236
        self->pulse_dest = self->pulse_centre + self->pulse_angle_90 * mp_obj_get_int(args[1]) / 90;
Damien George's avatar
Damien George committed
237
#endif
238
239
240
241
242
243
244
245
246
247
        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
248
249
250
    }
}

251
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_servo_angle_obj, 1, 3, pyb_servo_angle);
Damien George's avatar
Damien George committed
252

253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
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);

279
STATIC const mp_map_elem_t pyb_servo_locals_dict_table[] = {
280
281
    { MP_OBJ_NEW_QSTR(MP_QSTR_pulse_width), (mp_obj_t)&pyb_servo_pulse_width_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_calibrate), (mp_obj_t)&pyb_servo_calibrate_obj },
282
    { MP_OBJ_NEW_QSTR(MP_QSTR_angle), (mp_obj_t)&pyb_servo_angle_obj },
283
    { MP_OBJ_NEW_QSTR(MP_QSTR_speed), (mp_obj_t)&pyb_servo_speed_obj },
Damien George's avatar
Damien George committed
284
285
};

286
287
STATIC MP_DEFINE_CONST_DICT(pyb_servo_locals_dict, pyb_servo_locals_dict_table);

288
const mp_obj_type_t pyb_servo_type = {
Damien George's avatar
Damien George committed
289
290
    { &mp_type_type },
    .name = MP_QSTR_Servo,
291
292
    .print = pyb_servo_print,
    .make_new = pyb_servo_make_new,
293
    .locals_dict = (mp_obj_t)&pyb_servo_locals_dict,
Damien George's avatar
Damien George committed
294
};