1 files changed, 99 insertions, 0 deletions
diff --git a/esp8266/esponewire.c b/esp8266/esponewire.c
new file mode 100644
index 0000000000..797ec0bd22
--- /dev/null
+++ b/esp8266/esponewire.c
@@ -0,0 +1,99 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015-2016 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 <stdint.h>
+
+#include "etshal.h"
+#include "user_interface.h"
+#include "modpyb.h"
+#include "esponewire.h"
+
+#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)
+
+uint16_t esp_onewire_timings[9] = {480, 40, 420, 5, 5, 40, 10, 50, 10};
+
+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
+
+int esp_onewire_reset(uint pin) {
+    pin_set(pin, 0);
+    DELAY_US(esp_onewire_timings[TIMING_RESET1]);
+    uint32_t i = disable_irq();
+    pin_set(pin, 1);
+    DELAY_US(esp_onewire_timings[TIMING_RESET2]);
+    int status = !pin_get(pin);
+    enable_irq(i);
+    DELAY_US(esp_onewire_timings[TIMING_RESET3]);
+    return status;
+}
+
+int esp_onewire_readbit(uint pin) {
+    pin_set(pin, 1);
+    uint32_t i = disable_irq();
+    pin_set(pin, 0);
+    DELAY_US(esp_onewire_timings[TIMING_READ1]);
+    pin_set(pin, 1);
+    DELAY_US(esp_onewire_timings[TIMING_READ2]);
+    int value = pin_get(pin);
+    enable_irq(i);
+    DELAY_US(esp_onewire_timings[TIMING_READ3]);
+    return value;
+}
+
+void esp_onewire_writebit(uint pin, int value) {
+    uint32_t i = disable_irq();
+    pin_set(pin, 0);
+    DELAY_US(esp_onewire_timings[TIMING_WRITE1]);
+    if (value) {
+        pin_set(pin, 1);
+    }
+    DELAY_US(esp_onewire_timings[TIMING_WRITE2]);
+    pin_set(pin, 1);
+    DELAY_US(esp_onewire_timings[TIMING_WRITE3]);
+    enable_irq(i);
+}