servo.c 6.2 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
23
24
25
26
27
28
29
30
31
#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 pyb_servo_obj_t pyb_servo_obj[PYB_SERVO_NUM];

Damien George's avatar
Damien George committed
32
void servo_init(void) {
33
    timer_tim5_init();
34
35
36

    // reset servo objects
    for (int i = 0; i < PYB_SERVO_NUM; i++) {
37
        pyb_servo_obj[i].base.type = &pyb_servo_type;
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
        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;
    }
}

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) {
            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) {
61
62
63
64
                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;
65
66
67
68
            }
        }
    }
    if (need_it) {
69
        __HAL_TIM_ENABLE_IT(&TIM5_Handle, TIM_IT_UPDATE);
70
    } else {
71
        __HAL_TIM_DISABLE_IT(&TIM5_Handle, TIM_IT_UPDATE);
72
    }
Damien George's avatar
Damien George committed
73
74
}

75
STATIC void servo_init_channel(pyb_servo_obj_t *s) {
Damien George's avatar
Damien George committed
76
77
    uint32_t pin;
    uint32_t channel;
78
    switch (s->servo_id) {
Damien George's avatar
Damien George committed
79
80
81
82
83
84
85
86
87
88
89
90
91
        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;
92
    GPIO_InitStructure.Alternate = GPIO_AF2_TIM5;
Damien George's avatar
Damien George committed
93
94
95
96
97
    HAL_GPIO_Init(GPIOA, &GPIO_InitStructure);

    // PWM mode configuration
    TIM_OC_InitTypeDef oc_init;
    oc_init.OCMode = TIM_OCMODE_PWM1;
98
    oc_init.Pulse = s->pulse_cur; // units of 10us
Damien George's avatar
Damien George committed
99
100
    oc_init.OCPolarity = TIM_OCPOLARITY_HIGH;
    oc_init.OCFastMode = TIM_OCFAST_DISABLE;
101
    HAL_TIM_PWM_ConfigChannel(&TIM5_Handle, &oc_init, channel);
Damien George's avatar
Damien George committed
102
103

    // start PWM
104
    HAL_TIM_PWM_Start(&TIM5_Handle, channel);
Damien George's avatar
Damien George committed
105
106
107
108
109
110
111
112
113
114
115
}

/******************************************************************************/
// 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) {
116
117
118
119
        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
120
121
122
123
124
125
126
127
128
    }
    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);
129
130
    TIM5->ARR = pe;
    TIM5->CCR3 = pu;
Damien George's avatar
Damien George committed
131
132
133
134
135
    return mp_const_none;
}

MP_DEFINE_CONST_FUN_OBJ_2(pyb_pwm_set_obj, pyb_pwm_set);

136
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
137
    pyb_servo_obj_t *self = self_in;
138
    print(env, "<Servo %lu at %lu>", self->servo_id, self->pulse_cur);
Damien George's avatar
Damien George committed
139
140
}

141
142
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
143
    mp_check_nargs(n_args, 1, 1, n_kw, false);
144
145
146
147
148
149

    // 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)) {
150
        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "Servo %d does not exist", servo_id + 1));
151
152
153
154
155
156
157
158
159
160
161
162
    }

    // 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;
}

STATIC mp_obj_t pyb_servo_angle(uint n_args, const mp_obj_t *args) {
163
164
165
166
167
    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 {
Damien George's avatar
Damien George committed
168
#if MICROPY_ENABLE_FLOAT
169
        machine_int_t v = 152 + 85.0 * mp_obj_get_float(args[1]) / 90.0;
Damien George's avatar
Damien George committed
170
#else
171
        machine_int_t v = 152 + 85 * mp_obj_get_int(args[1]) / 90;
Damien George's avatar
Damien George committed
172
#endif
173
174
175
176
177
178
179
180
181
182
183
184
185
        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;
Damien George's avatar
Damien George committed
186
187
188
    }
}

189
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_servo_angle_obj, 1, 3, pyb_servo_angle);
Damien George's avatar
Damien George committed
190

191
192
STATIC const mp_map_elem_t pyb_servo_locals_dict_table[] = {
    { MP_OBJ_NEW_QSTR(MP_QSTR_angle), (mp_obj_t)&pyb_servo_angle_obj },
Damien George's avatar
Damien George committed
193
194
};

195
196
STATIC MP_DEFINE_CONST_DICT(pyb_servo_locals_dict, pyb_servo_locals_dict_table);

197
const mp_obj_type_t pyb_servo_type = {
Damien George's avatar
Damien George committed
198
199
    { &mp_type_type },
    .name = MP_QSTR_Servo,
200
201
    .print = pyb_servo_print,
    .make_new = pyb_servo_make_new,
202
    .locals_dict = (mp_obj_t)&pyb_servo_locals_dict,
Damien George's avatar
Damien George committed
203
};