circuitpython/shared-module/rotaryio/IncrementalEncoder.c

91 lines
3.5 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2021 Jeff Epler for Adafruit Industries
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#if CIRCUITPY_ROTARYIO && CIRCUITPY_ROTARYIO_SOFTENCODER
#include "shared-bindings/rotaryio/IncrementalEncoder.h"
#include "shared-module/rotaryio/IncrementalEncoder.h"
#include "common-hal/rotaryio/IncrementalEncoder.h"
void shared_module_softencoder_state_init(rotaryio_incrementalencoder_obj_t *self, uint8_t quiescent_state) {
self->state = quiescent_state;
self->sub_count = 0;
common_hal_rotaryio_incrementalencoder_set_position(self, 0);
}
void shared_module_softencoder_state_update(rotaryio_incrementalencoder_obj_t *self, uint8_t new_state) {
static const int8_t transitions[16] = {
0, // 00 -> 00 no movement
-1, // 00 -> 01 3/4 ccw (11 detent) or 1/4 ccw (00 at detent)
+1, // 00 -> 10 3/4 cw or 1/4 cw
0, // 00 -> 11 non-Gray-code transition
+1, // 01 -> 00 2/4 or 4/4 cw
0, // 01 -> 01 no movement
0, // 01 -> 10 non-Gray-code transition
-1, // 01 -> 11 4/4 or 2/4 ccw
-1, // 10 -> 00 2/4 or 4/4 ccw
0, // 10 -> 01 non-Gray-code transition
0, // 10 -> 10 no movement
+1, // 10 -> 11 4/4 or 2/4 cw
0, // 11 -> 00 non-Gray-code transition
+1, // 11 -> 01 1/4 or 3/4 cw
-1, // 11 -> 10 1/4 or 3/4 ccw
0, // 11 -> 11 no movement
};
new_state &= 0x3;
int idx = (self->state << 2) | new_state;
self->state = new_state;
int8_t sub_incr = transitions[idx];
self->sub_count += sub_incr;
if (self->sub_count >= self->divisor) {
self->position += 1;
self->sub_count = 0;
} else if (self->sub_count <= -self->divisor) {
self->position -= 1;
self->sub_count = 0;
}
}
mp_int_t common_hal_rotaryio_incrementalencoder_get_position(rotaryio_incrementalencoder_obj_t *self) {
return self->position;
}
void common_hal_rotaryio_incrementalencoder_set_position(rotaryio_incrementalencoder_obj_t *self, mp_int_t position) {
self->position = position;
}
mp_int_t common_hal_rotaryio_incrementalencoder_get_divisor(rotaryio_incrementalencoder_obj_t *self) {
return self->divisor;
}
void common_hal_rotaryio_incrementalencoder_set_divisor(rotaryio_incrementalencoder_obj_t *self, mp_int_t divisor) {
self->divisor = divisor;
}
#endif