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_arg_check_num(n_args, n_kw, 1, 1, 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
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);

196
STATIC mp_obj_t pyb_servo_calibration(uint n_args, const mp_obj_t *args) {
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
    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
222
    nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "calibration expecting 1, 4 or 6 arguments, got %d", n_args));
223 224
}

225
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_servo_calibration_obj, 1, 6, pyb_servo_calibration);
226

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
    { MP_OBJ_NEW_QSTR(MP_QSTR_pulse_width), (mp_obj_t)&pyb_servo_pulse_width_obj },
281
    { MP_OBJ_NEW_QSTR(MP_QSTR_calibration), (mp_obj_t)&pyb_servo_calibration_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
};