pybricks.robotics.DriveBase: Add brake().

Fixes pybricks/support#881

Author: laurensvalk

CHANGELOG.md

@@ -7,6 +7,7 @@
 ### Added
 - Added `hub.buttons` as an alias for `hub.button` on buttons with one
   hub ([support#1254]).
+- Implemented `brake` for `DriveBase` ([support#881]).
 
 ### Changed
 - The `use_gyro` method is added to the normal `DriveBase` class instead of
@@ -27,6 +28,7 @@
   tight loop ([support#1151]).
 
 [pybricks-micropython#104]: https://github.com/pybricks/pybricks-micropython/pull/104
+[support#881]: https://github.com/pybricks/support/issues/881
 [support#1054]: https://github.com/pybricks/support/issues/1054
 [support#1140]: https://github.com/pybricks/support/issues/1140
 [support#1151]: https://github.com/pybricks/support/issues/1151

pybricks/robotics/pb_type_drivebase.c

@@ -222,6 +222,20 @@ STATIC mp_obj_t pb_type_DriveBase_stop(mp_obj_t self_in) {
 }
 MP_DEFINE_CONST_FUN_OBJ_1(pb_type_DriveBase_stop_obj, pb_type_DriveBase_stop);
 
+// pybricks.robotics.DriveBase.brake
+STATIC mp_obj_t pb_type_DriveBase_brake(mp_obj_t self_in) {
+
+    // Cancel awaitables.
+    pb_type_DriveBase_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    pb_type_awaitable_update_all(self->awaitables, PB_TYPE_AWAITABLE_OPT_CANCEL_ALL);
+
+    // Stop hardware.
+    pb_assert(pbio_drivebase_stop(self->db, PBIO_CONTROL_ON_COMPLETION_BRAKE));
+
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_1(pb_type_DriveBase_brake_obj, pb_type_DriveBase_brake);
+
 // pybricks.robotics.DriveBase.distance
 STATIC mp_obj_t pb_type_DriveBase_distance(mp_obj_t self_in) {
     pb_type_DriveBase_obj_t *self = MP_OBJ_TO_PTR(self_in);
@@ -355,6 +369,7 @@ STATIC const mp_rom_map_elem_t pb_type_DriveBase_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_turn),             MP_ROM_PTR(&pb_type_DriveBase_turn_obj)     },
     { MP_ROM_QSTR(MP_QSTR_drive),            MP_ROM_PTR(&pb_type_DriveBase_drive_obj)    },
     { MP_ROM_QSTR(MP_QSTR_stop),             MP_ROM_PTR(&pb_type_DriveBase_stop_obj)     },
+    { MP_ROM_QSTR(MP_QSTR_brake),            MP_ROM_PTR(&pb_type_DriveBase_brake_obj)    },
     { MP_ROM_QSTR(MP_QSTR_distance),         MP_ROM_PTR(&pb_type_DriveBase_distance_obj) },
     { MP_ROM_QSTR(MP_QSTR_angle),            MP_ROM_PTR(&pb_type_DriveBase_angle_obj)    },
     { MP_ROM_QSTR(MP_QSTR_done),             MP_ROM_PTR(&pb_type_DriveBase_done_obj)     },