1 files changed, 67 insertions, 0 deletions
diff --git a/extmod/machine_pulse.c b/extmod/machine_pulse.c
new file mode 100644
index 0000000000..8c8bff510c
--- /dev/null
+++ b/extmod/machine_pulse.c
@@ -0,0 +1,67 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 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 "py/runtime.h"
+#include "py/mperrno.h"
+#include "extmod/machine_pulse.h"
+
+#if MICROPY_PY_MACHINE_PULSE
+
+mp_uint_t machine_time_pulse_us(mp_hal_pin_obj_t pin, int pulse_level, mp_uint_t timeout_us) {
+    mp_uint_t start = mp_hal_ticks_us();
+    while (mp_hal_pin_read(pin) != pulse_level) {
+        if ((mp_uint_t)(mp_hal_ticks_us() - start) >= timeout_us) {
+            return (mp_uint_t)-1;
+        }
+    }
+    start = mp_hal_ticks_us();
+    while (mp_hal_pin_read(pin) == pulse_level) {
+        if ((mp_uint_t)(mp_hal_ticks_us() - start) >= timeout_us) {
+            return (mp_uint_t)-1;
+        }
+    }
+    return mp_hal_ticks_us() - start;
+}
+
+STATIC mp_obj_t machine_time_pulse_us_(size_t n_args, const mp_obj_t *args) {
+    mp_hal_pin_obj_t pin = mp_hal_get_pin_obj(args[0]);
+    int level = 0;
+    if (mp_obj_is_true(args[1])) {
+        level = 1;
+    }
+    mp_uint_t timeout_us = 1000000;
+    if (n_args > 2) {
+        timeout_us = mp_obj_get_int(args[2]);
+    }
+    mp_uint_t us = machine_time_pulse_us(pin, level, timeout_us);
+    if (us == (mp_uint_t)-1) {
+        nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError, MP_OBJ_NEW_SMALL_INT(MP_ETIMEDOUT)));
+    }
+    return mp_obj_new_int(us);
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_time_pulse_us_obj, 2, 3, machine_time_pulse_us_);
+
+#endif