From da0d715d4991cab08d38bb0a0bef62508f6e1225 Mon Sep 17 00:00:00 2001
From: Fabio Manganiello <blacklight86@gmail.com>
Date: Fri, 2 Mar 2018 16:02:04 +0100
Subject: [PATCH] Getting distance synchronously

---
 .../plugins/gpio/sensor/distance/__init__.py  | 99 +++++++------------
 platypush/plugins/gpio/zeroborg/__init__.py   | 15 +--
 2 files changed, 37 insertions(+), 77 deletions(-)

diff --git a/platypush/plugins/gpio/sensor/distance/__init__.py b/platypush/plugins/gpio/sensor/distance/__init__.py
index b528ee12..e61f5403 100644
--- a/platypush/plugins/gpio/sensor/distance/__init__.py
+++ b/platypush/plugins/gpio/sensor/distance/__init__.py
@@ -12,7 +12,6 @@ class GpioSensorDistancePlugin(Plugin):
     def __init__(self, trigger_pin, echo_pin):
         self.trigger_pin = trigger_pin
         self.echo_pin = echo_pin
-        self.measured_distance_mm = None
         self._is_probing = False
 
         gpio.setmode(gpio.BCM)
@@ -24,75 +23,45 @@ class GpioSensorDistancePlugin(Plugin):
         time.sleep(1)
 
 
-    def start(self):
-        self._is_probing = True
-        logging.info('Received distance sensor start command')
-
-        def _run():
-            gpio.setmode(gpio.BCM)
-            gpio.setup(self.trigger_pin, gpio.OUT)
-            gpio.setup(self.echo_pin, gpio.IN)
-
-            while self._is_probing:
-                gpio.output(self.trigger_pin, True)
-                time.sleep(0.00001)  # 1 us pulse to trigger echo measurement
-                gpio.output(self.trigger_pin, False)
-                read_timeout = False
-
-                pulse_start = time.time()
-                pulse_on = pulse_start
-
-                while gpio.input(self.echo_pin) == 0:
-                    pulse_on = time.time()
-                    if pulse_on - pulse_start > 0.5:
-                        logging.warning('Distance sensor echo timeout: 0')
-                        read_timeout = True
-                        break
-
-                pulse_start = pulse_on
-                pulse_end = time.time()
-                pulse_off = pulse_end
-
-                while gpio.input(self.echo_pin) == 1:
-                    pulse_off = time.time()
-                    if pulse_off - pulse_end > 0.5:
-                        logging.warning('Distance sensor echo timeout: 1')
-                        read_timeout = True
-                        break
-
-                if read_timeout:
-                    continue
-
-                pulse_end = pulse_off
-                pulse_duration = pulse_end - pulse_start
-
-                # s = vt where v = avg speed of sound
-                self.measured_distance_mm = round(pulse_duration * 171500.0, 2)
-
-                gpio.output(self.trigger_pin, False)
-                time.sleep(0.1)
-
-            gpio.cleanup()
-            self.measured_distance_mm = None
-
-        self._probe_thread = threading.Thread(target=_run)
-        self._probe_thread.start()
-
-        return Response(output={'status': 'probing'})
-
-
     def get_distance(self):
-        return self.measured_distance_mm
+        gpio.setmode(gpio.BCM)
+        gpio.setup(self.trigger_pin, gpio.OUT)
+        gpio.setup(self.echo_pin, gpio.IN)
 
+        gpio.output(self.trigger_pin, True)
+        time.sleep(0.00001)  # 1 us pulse to trigger echo measurement
+        gpio.output(self.trigger_pin, False)
+        read_timeout = False
 
-    def stop(self):
-        self._is_probing = False
-        self.measured_distance_mm = None
+        pulse_start = time.time()
+        pulse_on = pulse_start
 
-        if self._probe_thread and threading.get_ident() != self._probe_thread.ident:
-            self._probe_thread.join()
+        while gpio.input(self.echo_pin) == 0:
+            pulse_on = time.time()
+            if pulse_on - pulse_start > 0.5:
+                logging.warning('Distance sensor echo timeout: 0')
+                read_timeout = True
+                break
 
-        return Response(output={'status':'stopped'})
+        pulse_start = pulse_on
+        pulse_end = time.time()
+        pulse_off = pulse_end
+
+        while gpio.input(self.echo_pin) == 1:
+            pulse_off = time.time()
+            if pulse_off - pulse_end > 0.5:
+                logging.warning('Distance sensor echo timeout: 1')
+                read_timeout = True
+                break
+
+        if read_timeout:
+            return None
+
+        pulse_end = pulse_off
+        pulse_duration = pulse_end - pulse_start
+
+        # s = vt where v = avg speed of sound
+        return round(pulse_duration * 171500.0, 2)
 
 
 # vim:sw=4:ts=4:et:
diff --git a/platypush/plugins/gpio/zeroborg/__init__.py b/platypush/plugins/gpio/zeroborg/__init__.py
index dad4b588..b00b4021 100644
--- a/platypush/plugins/gpio/zeroborg/__init__.py
+++ b/platypush/plugins/gpio/zeroborg/__init__.py
@@ -40,7 +40,6 @@ class GpioZeroborgPlugin(Plugin):
         self.v_in = v_in
         self.v_out = v_out
         self.max_power = v_out / float(v_in)
-        self.distance_sensor = None
         self.auto_mode = False
 
         self.zb = ZeroBorg.ZeroBorg()
@@ -50,16 +49,11 @@ class GpioZeroborgPlugin(Plugin):
 
 
     def get_distance(self):
-        if not self.distance_sensor:
-            self.distance_sensor = get_plugin('gpio.sensor.distance')
-
-        if not self.distance_sensor:
+        distance_sensor = get_plugin('gpio.sensor.distance')
+        if not distance_sensor:
             raise RuntimeError('No gpio.sensor.distance configuration found')
 
-        if self.distance_sensor.get_distance() is None:
-            self.distance_sensor.start()
-
-        return self.distance_sensor.get_distance()
+        return distance_sensor.get_distance()
 
 
     def drive(self, direction):
@@ -126,9 +120,6 @@ class GpioZeroborgPlugin(Plugin):
         self.zb.MotorsOff()
         self.zb.ResetEpo()
 
-        if self.distance_sensor:
-            self.distance_sensor.stop()
-
         return Response(output={'status':'stopped'})