esp8266: Add onewire helper functions as C module.

Includes functions to read and write bits and bytes.
This commit is contained in:
Damien George 2015-12-29 00:20:34 +00:00 committed by Paul Sokolovsky
parent 0cdbd356fd
commit 78d0dde562
4 changed files with 199 additions and 0 deletions

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

185
esp8266/modonewire.c Normal file
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@ -0,0 +1,185 @@
/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2015 Damien P. George
*
* 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 <stdio.h>
#include <stdint.h>
#include "etshal.h"
#include "user_interface.h"
#include "py/obj.h"
#include "py/mphal.h"
#include "modpyb.h"
STATIC uint32_t disable_irq(void) {
ets_intr_lock();
return 0;
}
STATIC void enable_irq(uint32_t i) {
ets_intr_unlock();
}
STATIC void mp_hal_delay_us_no_irq(uint32_t us) {
uint32_t start = system_get_time();
while (system_get_time() - start < us) {
}
}
#define DELAY_US mp_hal_delay_us_no_irq
#define TIMING_RESET1 (0)
#define TIMING_RESET2 (1)
#define TIMING_RESET3 (2)
#define TIMING_READ1 (3)
#define TIMING_READ2 (4)
#define TIMING_READ3 (5)
#define TIMING_WRITE1 (6)
#define TIMING_WRITE2 (7)
#define TIMING_WRITE3 (8)
static int timings[] = {480, 40, 420, 5, 5, 40, 10, 50, 10};
STATIC mp_obj_t onewire_timings(mp_obj_t timings_in) {
mp_obj_t *items;
mp_obj_get_array_fixed_n(timings_in, 9, &items);
for (int i = 0; i < 9; ++i) {
timings[i] = mp_obj_get_int(items[i]);
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(onewire_timings_obj, onewire_timings);
STATIC mp_obj_t onewire_reset(mp_obj_t pin_in) {
uint pin = mp_obj_get_pin(pin_in);
pin_set(pin, 0);
DELAY_US(timings[TIMING_RESET1]);
uint32_t i = disable_irq();
pin_set(pin, 1);
DELAY_US(timings[TIMING_RESET2]);
int status = !pin_get(pin);
enable_irq(i);
DELAY_US(timings[TIMING_RESET3]);
return mp_obj_new_bool(status);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(onewire_reset_obj, onewire_reset);
STATIC int _onewire_readbit(uint pin) {
pin_set(pin, 1);
uint32_t i = disable_irq();
pin_set(pin, 0);
DELAY_US(timings[TIMING_READ1]);
pin_set(pin, 1);
DELAY_US(timings[TIMING_READ2]);
int value = pin_get(pin);
enable_irq(i);
DELAY_US(timings[TIMING_READ3]);
return value;
}
STATIC mp_obj_t onewire_readbit(mp_obj_t pin_in) {
return MP_OBJ_NEW_SMALL_INT(_onewire_readbit(mp_obj_get_pin(pin_in)));
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(onewire_readbit_obj, onewire_readbit);
STATIC mp_obj_t onewire_readbyte(mp_obj_t pin_in) {
uint pin = mp_obj_get_pin(pin_in);
uint8_t value = 0;
for (int i = 0; i < 8; ++i) {
value |= _onewire_readbit(pin) << i;
}
return MP_OBJ_NEW_SMALL_INT(value);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(onewire_readbyte_obj, onewire_readbyte);
STATIC void _onewire_writebit(uint pin, int value) {
uint32_t i = disable_irq();
pin_set(pin, 0);
DELAY_US(timings[TIMING_WRITE1]);
pin_set(pin, value);
DELAY_US(timings[TIMING_WRITE2]);
pin_set(pin, 1);
DELAY_US(timings[TIMING_WRITE3]);
enable_irq(i);
}
STATIC mp_obj_t onewire_writebit(mp_obj_t pin_in, mp_obj_t value_in) {
_onewire_writebit(mp_obj_get_pin(pin_in), mp_obj_get_int(value_in));
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(onewire_writebit_obj, onewire_writebit);
STATIC mp_obj_t onewire_writebyte(mp_obj_t pin_in, mp_obj_t value_in) {
uint pin = mp_obj_get_pin(pin_in);
int value = mp_obj_get_int(value_in);
for (int i = 0; i < 8; ++i) {
_onewire_writebit(pin, value & 1);
value >>= 1;
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(onewire_writebyte_obj, onewire_writebyte);
STATIC mp_obj_t onewire_crc8(mp_obj_t data) {
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(data, &bufinfo, MP_BUFFER_READ);
uint8_t crc = 0;
for (size_t i = 0; i < bufinfo.len; ++i) {
uint8_t byte = ((uint8_t*)bufinfo.buf)[i];
for (int b = 0; b < 8; ++b) {
uint8_t fb_bit = (crc ^ byte) & 0x01;
if (fb_bit == 0x01) {
crc = crc ^ 0x18;
}
crc = (crc >> 1) & 0x7f;
if (fb_bit == 0x01) {
crc = crc | 0x80;
}
byte = byte >> 1;
}
}
return MP_OBJ_NEW_SMALL_INT(crc);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(onewire_crc8_obj, onewire_crc8);
STATIC const mp_map_elem_t onewire_module_globals_table[] = {
{ MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_onewire) },
{ MP_ROM_QSTR(MP_QSTR_timings), MP_ROM_PTR((mp_obj_t)&onewire_timings_obj) },
{ MP_ROM_QSTR(MP_QSTR_reset), MP_ROM_PTR((mp_obj_t)&onewire_reset_obj) },
{ MP_ROM_QSTR(MP_QSTR_readbit), MP_ROM_PTR((mp_obj_t)&onewire_readbit_obj) },
{ MP_ROM_QSTR(MP_QSTR_readbyte), MP_ROM_PTR((mp_obj_t)&onewire_readbyte_obj) },
{ MP_ROM_QSTR(MP_QSTR_writebit), MP_ROM_PTR((mp_obj_t)&onewire_writebit_obj) },
{ MP_ROM_QSTR(MP_QSTR_writebyte), MP_ROM_PTR((mp_obj_t)&onewire_writebyte_obj) },
{ MP_ROM_QSTR(MP_QSTR_crc8), MP_ROM_PTR((mp_obj_t)&onewire_crc8_obj) },
};
STATIC MP_DEFINE_CONST_DICT(onewire_module_globals, onewire_module_globals_table);
const mp_obj_module_t onewire_module = {
.base = { &mp_type_module },
.name = MP_QSTR_onewire,
.globals = (mp_obj_dict_t*)&onewire_module_globals,
};

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

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