100 lines
2.9 KiB
C
100 lines
2.9 KiB
C
/*
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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) 2015-2016 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 <stdint.h>
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#include "etshal.h"
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#include "user_interface.h"
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#include "modpyb.h"
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#include "esponewire.h"
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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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uint16_t esp_onewire_timings[9] = {480, 40, 420, 5, 5, 40, 10, 50, 10};
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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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int esp_onewire_reset(uint pin) {
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pin_set(pin, 0);
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DELAY_US(esp_onewire_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(esp_onewire_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(esp_onewire_timings[TIMING_RESET3]);
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return status;
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}
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int esp_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(esp_onewire_timings[TIMING_READ1]);
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pin_set(pin, 1);
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DELAY_US(esp_onewire_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(esp_onewire_timings[TIMING_READ3]);
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return value;
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}
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void esp_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(esp_onewire_timings[TIMING_WRITE1]);
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if (value) {
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pin_set(pin, 1);
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}
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DELAY_US(esp_onewire_timings[TIMING_WRITE2]);
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pin_set(pin, 1);
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DELAY_US(esp_onewire_timings[TIMING_WRITE3]);
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enable_irq(i);
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}
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