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esp8266: Add onewire helper functions as C module.
Includes functions to read and write bits and bytes.
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‎esp8266/Makefile‎

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@@ -67,6 +67,7 @@ SRC_C = \
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modutime.c \
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moduos.c \
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modmachine.c \
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modonewire.c \
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utils.c \
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ets_alt_task.c \
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$(BUILD)/frozen.c \

‎esp8266/modonewire.c‎

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/*
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* This file is part of the MicroPython project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2015 Damien P. George
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include <stdio.h>
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#include <stdint.h>
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#include "etshal.h"
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#include "user_interface.h"
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#include "py/obj.h"
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#include "py/mphal.h"
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#include "modpyb.h"
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STATIC uint32_t disable_irq(void) {
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ets_intr_lock();
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return 0;
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}
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STATIC void enable_irq(uint32_t i) {
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ets_intr_unlock();
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}
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STATIC void mp_hal_delay_us_no_irq(uint32_t us) {
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uint32_t start = system_get_time();
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while (system_get_time() - start < us) {
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}
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}
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#define DELAY_US mp_hal_delay_us_no_irq
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#define TIMING_RESET1 (0)
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#define TIMING_RESET2 (1)
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#define TIMING_RESET3 (2)
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#define TIMING_READ1 (3)
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#define TIMING_READ2 (4)
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#define TIMING_READ3 (5)
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#define TIMING_WRITE1 (6)
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#define TIMING_WRITE2 (7)
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#define TIMING_WRITE3 (8)
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static int timings[] = {480, 40, 420, 5, 5, 40, 10, 50, 10};
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STATIC mp_obj_t onewire_timings(mp_obj_t timings_in) {
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mp_obj_t *items;
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mp_obj_get_array_fixed_n(timings_in, 9, &items);
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for (int i = 0; i < 9; ++i) {
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timings[i] = mp_obj_get_int(items[i]);
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}
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return mp_const_none;
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}
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STATIC MP_DEFINE_CONST_FUN_OBJ_1(onewire_timings_obj, onewire_timings);
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STATIC mp_obj_t onewire_reset(mp_obj_t pin_in) {
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uint pin = mp_obj_get_pin(pin_in);
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pin_set(pin, 0);
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DELAY_US(timings[TIMING_RESET1]);
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uint32_t i = disable_irq();
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pin_set(pin, 1);
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DELAY_US(timings[TIMING_RESET2]);
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int status = !pin_get(pin);
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enable_irq(i);
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DELAY_US(timings[TIMING_RESET3]);
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return mp_obj_new_bool(status);
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}
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STATIC MP_DEFINE_CONST_FUN_OBJ_1(onewire_reset_obj, onewire_reset);
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STATIC int _onewire_readbit(uint pin) {
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pin_set(pin, 1);
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uint32_t i = disable_irq();
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pin_set(pin, 0);
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DELAY_US(timings[TIMING_READ1]);
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pin_set(pin, 1);
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DELAY_US(timings[TIMING_READ2]);
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int value = pin_get(pin);
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enable_irq(i);
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DELAY_US(timings[TIMING_READ3]);
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return value;
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}
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STATIC mp_obj_t onewire_readbit(mp_obj_t pin_in) {
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return MP_OBJ_NEW_SMALL_INT(_onewire_readbit(mp_obj_get_pin(pin_in)));
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}
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STATIC MP_DEFINE_CONST_FUN_OBJ_1(onewire_readbit_obj, onewire_readbit);
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STATIC mp_obj_t onewire_readbyte(mp_obj_t pin_in) {
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uint pin = mp_obj_get_pin(pin_in);
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uint8_t value = 0;
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for (int i = 0; i < 8; ++i) {
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value |= _onewire_readbit(pin) << i;
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}
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return MP_OBJ_NEW_SMALL_INT(value);
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}
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STATIC MP_DEFINE_CONST_FUN_OBJ_1(onewire_readbyte_obj, onewire_readbyte);
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STATIC void _onewire_writebit(uint pin, int value) {
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uint32_t i = disable_irq();
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pin_set(pin, 0);
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DELAY_US(timings[TIMING_WRITE1]);
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pin_set(pin, value);
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DELAY_US(timings[TIMING_WRITE2]);
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pin_set(pin, 1);
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DELAY_US(timings[TIMING_WRITE3]);
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enable_irq(i);
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}
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STATIC mp_obj_t onewire_writebit(mp_obj_t pin_in, mp_obj_t value_in) {
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_onewire_writebit(mp_obj_get_pin(pin_in), mp_obj_get_int(value_in));
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return mp_const_none;
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}
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STATIC MP_DEFINE_CONST_FUN_OBJ_2(onewire_writebit_obj, onewire_writebit);
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STATIC mp_obj_t onewire_writebyte(mp_obj_t pin_in, mp_obj_t value_in) {
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uint pin = mp_obj_get_pin(pin_in);
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int value = mp_obj_get_int(value_in);
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for (int i = 0; i < 8; ++i) {
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_onewire_writebit(pin, value & 1);
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value >>= 1;
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}
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return mp_const_none;
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}
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STATIC MP_DEFINE_CONST_FUN_OBJ_2(onewire_writebyte_obj, onewire_writebyte);
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STATIC mp_obj_t onewire_crc8(mp_obj_t data) {
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mp_buffer_info_t bufinfo;
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mp_get_buffer_raise(data, &bufinfo, MP_BUFFER_READ);
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uint8_t crc = 0;
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for (size_t i = 0; i < bufinfo.len; ++i) {
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uint8_t byte = ((uint8_t*)bufinfo.buf)[i];
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for (int b = 0; b < 8; ++b) {
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uint8_t fb_bit = (crc ^ byte) & 0x01;
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if (fb_bit == 0x01) {
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crc = crc ^ 0x18;
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}
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crc = (crc >> 1) & 0x7f;
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if (fb_bit == 0x01) {
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crc = crc | 0x80;
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}
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byte = byte >> 1;
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}
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}
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return MP_OBJ_NEW_SMALL_INT(crc);
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}
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STATIC MP_DEFINE_CONST_FUN_OBJ_1(onewire_crc8_obj, onewire_crc8);
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STATIC const mp_map_elem_t onewire_module_globals_table[] = {
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{ MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_onewire) },
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{ MP_ROM_QSTR(MP_QSTR_timings), MP_ROM_PTR((mp_obj_t)&onewire_timings_obj) },
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{ MP_ROM_QSTR(MP_QSTR_reset), MP_ROM_PTR((mp_obj_t)&onewire_reset_obj) },
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{ MP_ROM_QSTR(MP_QSTR_readbit), MP_ROM_PTR((mp_obj_t)&onewire_readbit_obj) },
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{ MP_ROM_QSTR(MP_QSTR_readbyte), MP_ROM_PTR((mp_obj_t)&onewire_readbyte_obj) },
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{ MP_ROM_QSTR(MP_QSTR_writebit), MP_ROM_PTR((mp_obj_t)&onewire_writebit_obj) },
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{ MP_ROM_QSTR(MP_QSTR_writebyte), MP_ROM_PTR((mp_obj_t)&onewire_writebyte_obj) },
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{ MP_ROM_QSTR(MP_QSTR_crc8), MP_ROM_PTR((mp_obj_t)&onewire_crc8_obj) },
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};
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STATIC MP_DEFINE_CONST_DICT(onewire_module_globals, onewire_module_globals_table);
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const mp_obj_module_t onewire_module = {
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.base = { &mp_type_module },
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.name = MP_QSTR_onewire,
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.globals = (mp_obj_dict_t*)&onewire_module_globals,
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};

‎esp8266/mpconfigport.h‎

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@@ -94,6 +94,7 @@ extern const struct _mp_obj_module_t utime_module;
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extern const struct _mp_obj_module_t uos_module;
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extern const struct _mp_obj_module_t mp_module_lwip;
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extern const struct _mp_obj_module_t mp_module_machine;
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extern const struct _mp_obj_module_t onewire_module;
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#define MICROPY_PORT_BUILTIN_MODULES \
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{ MP_OBJ_NEW_QSTR(MP_QSTR_pyb), (mp_obj_t)&pyb_module }, \
@@ -105,6 +106,7 @@ extern const struct _mp_obj_module_t mp_module_machine;
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{ MP_OBJ_NEW_QSTR(MP_QSTR_utime), (mp_obj_t)&utime_module }, \
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{ MP_OBJ_NEW_QSTR(MP_QSTR_uos), (mp_obj_t)&uos_module }, \
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{ MP_OBJ_NEW_QSTR(MP_QSTR_machine), (mp_obj_t)&mp_module_machine }, \
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{ MP_OBJ_NEW_QSTR(MP_QSTR__onewire), (mp_obj_t)&onewire_module }, \
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#define MICROPY_PORT_BUILTIN_MODULE_WEAK_LINKS \
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{ MP_OBJ_NEW_QSTR(MP_QSTR_time), (mp_obj_t)&utime_module }, \

‎esp8266/qstrdefsport.h‎

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@@ -178,4 +178,15 @@ Q(period)
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Q(ONE_SHOT)
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Q(PERIODIC)
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// onewire
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Q(_onewire)
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Q(onewire)
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Q(timings)
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Q(reset)
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Q(readbit)
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Q(readbyte)
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Q(writebit)
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Q(writebyte)
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Q(crc8)
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Q(json)

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