circuitpython/ports/espressif/common-hal/rotaryio/IncrementalEncoder.c
Jeff Epler 9eebb3dbab rotaryio: Add the ability to set the divisor
At present, Adafruit's rotary encoders all move 1 quadrature cycle per
detent, so we originally hard-coded division-by-4.  However, other
encoders exist, including ones without detents, ones with 2 detents per
cycle, and others with 4 detents per cycle.

The new `divisor` property and constructor argument allows selecting
a divisor of 1, 2, or 4; with the default of 4 giving backward
compatibility.

The property is not supported (yet?) on espressif MCUs; it throws an
error if a value other than 4 is set.
2021-10-16 09:43:45 -05:00

97 lines
3.7 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2020 microDev
*
* 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.
*/
#include "common-hal/rotaryio/IncrementalEncoder.h"
#include "common-hal/microcontroller/Pin.h"
#include "py/runtime.h"
#include "supervisor/shared/translate.h"
void common_hal_rotaryio_incrementalencoder_construct(rotaryio_incrementalencoder_obj_t *self,
const mcu_pin_obj_t *pin_a, const mcu_pin_obj_t *pin_b) {
claim_pin(pin_a);
claim_pin(pin_b);
// Prepare configuration for the PCNT unit
const pcnt_config_t pcnt_config = {
// Set PCNT input signal and control GPIOs
.pulse_gpio_num = pin_a->number,
.ctrl_gpio_num = pin_b->number,
.channel = PCNT_CHANNEL_0,
// What to do on the positive / negative edge of pulse input?
.pos_mode = PCNT_COUNT_DEC, // Count up on the positive edge
.neg_mode = PCNT_COUNT_INC, // Keep the counter value on the negative edge
// What to do when control input is low or high?
.lctrl_mode = PCNT_MODE_REVERSE, // Reverse counting direction if low
.hctrl_mode = PCNT_MODE_KEEP, // Keep the primary counter mode if high
};
// Initialize PCNT unit
const int8_t unit = peripherals_pcnt_init(pcnt_config);
if (unit == -1) {
mp_raise_RuntimeError(translate("All PCNT units in use"));
}
self->pin_a = pin_a->number;
self->pin_b = pin_b->number;
self->unit = (pcnt_unit_t)unit;
}
bool common_hal_rotaryio_incrementalencoder_deinited(rotaryio_incrementalencoder_obj_t *self) {
return self->unit == PCNT_UNIT_MAX;
}
void common_hal_rotaryio_incrementalencoder_deinit(rotaryio_incrementalencoder_obj_t *self) {
if (common_hal_rotaryio_incrementalencoder_deinited(self)) {
return;
}
reset_pin_number(self->pin_a);
reset_pin_number(self->pin_b);
peripherals_pcnt_deinit(&self->unit);
}
mp_int_t common_hal_rotaryio_incrementalencoder_get_position(rotaryio_incrementalencoder_obj_t *self) {
int16_t count;
pcnt_get_counter_value(self->unit, &count);
return (count / 2) + self->position;
}
void common_hal_rotaryio_incrementalencoder_set_position(rotaryio_incrementalencoder_obj_t *self,
mp_int_t new_position) {
self->position = new_position;
pcnt_counter_clear(self->unit);
}
mp_int_t common_hal_rotaryio_incrementalencoder_get_divisor(rotaryio_incrementalencoder_obj_t *self) {
return 4;
}
void common_hal_rotaryio_incrementalencoder_set_divisor(rotaryio_incrementalencoder_obj_t *self, mp_int_t divisor) {
if (divisor != 4) {
mp_raise_ValueError(translate("divisor must be 4"));
}
}