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dpgeorgedpgeorge
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stmhal: Add functionality to Servo object.
Can now calibrate, set pulse width, angle and speed.
1 parent d9ec625 commit 2293471

2 files changed

Lines changed: 107 additions & 13 deletions

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‎stmhal/qstrdefsport.h‎

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -108,7 +108,10 @@ Q(dma)
108108

109109
// for Servo object
110110
Q(Servo)
111+
Q(pulse_width)
112+
Q(calibrate)
111113
Q(angle)
114+
Q(speed)
112115

113116
// for os module
114117
Q(os)

‎stmhal/servo.c‎

Lines changed: 104 additions & 13 deletions
Original file line numberDiff line numberDiff line change
@@ -20,11 +20,16 @@
2020

2121
typedef struct _pyb_servo_obj_t {
2222
mp_obj_base_t base;
23-
uint16_t servo_id;
24-
uint16_t time_left;
23+
uint8_t servo_id;
24+
uint8_t pulse_min; // units of 10us
25+
uint8_t pulse_max; // units of 10us
26+
uint8_t pulse_centre; // units of 10us
27+
uint8_t pulse_angle_90; // units of 10us; pulse at 90 degrees, minus pulse_centre
28+
uint8_t pulse_speed_100; // units of 10us; pulse at 100% forward speed, minus pulse_centre
29+
uint16_t pulse_cur; // units of 10us
30+
uint16_t pulse_dest; // units of 10us
2531
int16_t pulse_accum;
26-
uint16_t pulse_cur;
27-
uint16_t pulse_dest;
32+
uint16_t time_left;
2833
} pyb_servo_obj_t;
2934

3035
STATIC pyb_servo_obj_t pyb_servo_obj[PYB_SERVO_NUM];
@@ -36,9 +41,14 @@ void servo_init(void) {
3641
for (int i = 0; i < PYB_SERVO_NUM; i++) {
3742
pyb_servo_obj[i].base.type = &pyb_servo_type;
3843
pyb_servo_obj[i].servo_id = i + 1;
39-
pyb_servo_obj[i].time_left = 0;
40-
pyb_servo_obj[i].pulse_cur = 150; // units of 10us
44+
pyb_servo_obj[i].pulse_min = 64;
45+
pyb_servo_obj[i].pulse_max = 242;
46+
pyb_servo_obj[i].pulse_centre = 150;
47+
pyb_servo_obj[i].pulse_angle_90 = 97;
48+
pyb_servo_obj[i].pulse_speed_100 = 70;
49+
pyb_servo_obj[i].pulse_cur = 150;
4150
pyb_servo_obj[i].pulse_dest = 0;
51+
pyb_servo_obj[i].time_left = 0;
4252
}
4353
}
4454

@@ -47,6 +57,13 @@ void servo_timer_irq_callback(void) {
4757
for (int i = 0; i < PYB_SERVO_NUM; i++) {
4858
pyb_servo_obj_t *s = &pyb_servo_obj[i];
4959
if (s->pulse_cur != s->pulse_dest) {
60+
// clamp pulse to within min/max
61+
if (s->pulse_dest < s->pulse_min) {
62+
s->pulse_dest = s->pulse_min;
63+
} else if (s->pulse_dest > s->pulse_max) {
64+
s->pulse_dest = s->pulse_max;
65+
}
66+
// adjust cur to get closer to dest
5067
if (s->time_left <= 1) {
5168
s->pulse_cur = s->pulse_dest;
5269
s->time_left = 0;
@@ -57,6 +74,7 @@ void servo_timer_irq_callback(void) {
5774
s->time_left--;
5875
need_it = true;
5976
}
77+
// set the pulse width
6078
switch (s->servo_id) {
6179
case 1: TIM5->CCR1 = s->pulse_cur; break;
6280
case 2: TIM5->CCR2 = s->pulse_cur; break;
@@ -135,7 +153,7 @@ MP_DEFINE_CONST_FUN_OBJ_2(pyb_pwm_set_obj, pyb_pwm_set);
135153

136154
STATIC void pyb_servo_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
137155
pyb_servo_obj_t *self = self_in;
138-
print(env, "<Servo %lu at %lu>", self->servo_id, self->pulse_cur);
156+
print(env, "<Servo %lu at %luus>", self->servo_id, 10 * self->pulse_cur);
139157
}
140158

141159
STATIC mp_obj_t pyb_servo_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
@@ -159,20 +177,64 @@ STATIC mp_obj_t pyb_servo_make_new(mp_obj_t type_in, uint n_args, uint n_kw, con
159177
return s;
160178
}
161179

180+
STATIC mp_obj_t pyb_servo_pulse_width(uint n_args, const mp_obj_t *args) {
181+
pyb_servo_obj_t *self = args[0];
182+
if (n_args == 1) {
183+
// get pulse width, in us
184+
return mp_obj_new_int(10 * self->pulse_cur);
185+
} else {
186+
// set pulse width, in us
187+
self->pulse_dest = mp_obj_get_int(args[1]) / 10;
188+
self->time_left = 0;
189+
servo_timer_irq_callback();
190+
return mp_const_none;
191+
}
192+
}
193+
194+
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_servo_pulse_width_obj, 1, 2, pyb_servo_pulse_width);
195+
196+
STATIC mp_obj_t pyb_servo_calibrate(uint n_args, const mp_obj_t *args) {
197+
pyb_servo_obj_t *self = args[0];
198+
if (n_args == 1) {
199+
// get calibration values
200+
mp_obj_t tuple[5];
201+
tuple[0] = mp_obj_new_int(10 * self->pulse_min);
202+
tuple[1] = mp_obj_new_int(10 * self->pulse_max);
203+
tuple[2] = mp_obj_new_int(10 * self->pulse_centre);
204+
tuple[3] = mp_obj_new_int(10 * (self->pulse_angle_90 + self->pulse_centre));
205+
tuple[4] = mp_obj_new_int(10 * (self->pulse_speed_100 + self->pulse_centre));
206+
return mp_obj_new_tuple(5, tuple);
207+
} else if (n_args >= 4) {
208+
// set min, max, centre
209+
self->pulse_min = mp_obj_get_int(args[1]) / 10;
210+
self->pulse_max = mp_obj_get_int(args[2]) / 10;
211+
self->pulse_centre = mp_obj_get_int(args[3]) / 10;
212+
if (n_args == 4) {
213+
return mp_const_none;
214+
} else if (n_args == 6) {
215+
self->pulse_angle_90 = mp_obj_get_int(args[4]) / 10 - self->pulse_centre;
216+
self->pulse_speed_100 = mp_obj_get_int(args[5]) / 10 - self->pulse_centre;
217+
return mp_const_none;
218+
}
219+
}
220+
221+
// bad number of arguments
222+
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "calibrate expecting 1, 4 or 6 arguments, got %d", n_args));
223+
}
224+
225+
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_servo_calibrate_obj, 1, 6, pyb_servo_calibrate);
226+
162227
STATIC mp_obj_t pyb_servo_angle(uint n_args, const mp_obj_t *args) {
163228
pyb_servo_obj_t *self = args[0];
164229
if (n_args == 1) {
165230
// get angle
166-
return mp_obj_new_int((self->pulse_cur - 152) * 90 / 85);
231+
return mp_obj_new_int((self->pulse_cur - self->pulse_centre) * 90 / self->pulse_angle_90);
167232
} else {
168233
#if MICROPY_ENABLE_FLOAT
169-
machine_int_t v = 152 + 85.0 * mp_obj_get_float(args[1]) / 90.0;
234+
self->pulse_dest = self->pulse_centre + self->pulse_angle_90 * mp_obj_get_float(args[1]) / 90.0;
170235
#else
171-
machine_int_t v = 152 + 85 * mp_obj_get_int(args[1]) / 90;
236+
self->pulse_dest = self->pulse_centre + self->pulse_angle_90 * mp_obj_get_int(args[1]) / 90;
172237
#endif
173-
if (v < 65) { v = 65; }
174-
if (v > 210) { v = 210; }
175-
self->pulse_dest = v;
176238
if (n_args == 2) {
177239
// set angle immediately
178240
self->time_left = 0;
@@ -188,8 +250,37 @@ STATIC mp_obj_t pyb_servo_angle(uint n_args, const mp_obj_t *args) {
188250

189251
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_servo_angle_obj, 1, 3, pyb_servo_angle);
190252

253+
STATIC mp_obj_t pyb_servo_speed(uint n_args, const mp_obj_t *args) {
254+
pyb_servo_obj_t *self = args[0];
255+
if (n_args == 1) {
256+
// get speed
257+
return mp_obj_new_int((self->pulse_cur - self->pulse_centre) * 100 / self->pulse_speed_100);
258+
} else {
259+
#if MICROPY_ENABLE_FLOAT
260+
self->pulse_dest = self->pulse_centre + self->pulse_speed_100 * mp_obj_get_float(args[1]) / 100.0;
261+
#else
262+
self->pulse_dest = self->pulse_centre + self->pulse_speed_100 * mp_obj_get_int(args[1]) / 100;
263+
#endif
264+
if (n_args == 2) {
265+
// set speed immediately
266+
self->time_left = 0;
267+
} else {
268+
// set speed over a given time (given in milli seconds)
269+
self->time_left = mp_obj_get_int(args[2]) / 20;
270+
self->pulse_accum = 0;
271+
}
272+
servo_timer_irq_callback();
273+
return mp_const_none;
274+
}
275+
}
276+
277+
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_servo_speed_obj, 1, 3, pyb_servo_speed);
278+
191279
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_calibrate), (mp_obj_t)&pyb_servo_calibrate_obj },
192282
{ 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 },
193284
};
194285

195286
STATIC MP_DEFINE_CONST_DICT(pyb_servo_locals_dict, pyb_servo_locals_dict_table);

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