revert srf node to not use edges

seems more reliable to me... :-)

hardware/PiSrf/nrsrf.py

@@ -16,48 +16,32 @@ ECHO    = 0
 TRIGGER = 0
 OLD = 0
 SLEEP = 0.5
+MAX_DIST = 400
 
 def Measure():
-    start = 0
+    realstart = time.time()
     GPIO.output(TRIGGER, True)
     time.sleep(0.00001)
     GPIO.output(TRIGGER, False)
+    while GPIO.input(ECHO)==0:
+        start = time.time()
+        Dif = time.time() - realstart
+        if Dif > 0.2:
+            print("Ultrasonic Sensor Timed out, Restart.")
+            time.sleep(0.4)
+            return 400
+    while GPIO.input(ECHO)==1:
+        stop = time.time()
+        Dif = time.time() - realstart
+        if Dif > 0.4:
+            print("Ultrasonic Sensor Timed out, Restarting.")
+            time.sleep(0.2)
+            return 400
 
-    channel = GPIO.wait_for_edge(ECHO, GPIO.BOTH, timeout=200)
-    if channel is None:
-        print("Ultrasonic sensor timed out (pre-echo).")
-        GPIO.remove_event_detect(ECHO)
-        restart()
-    # else:
-        # print("Echo start detected")
-    start = time.time()
-
-    GPIO.wait_for_edge(ECHO, GPIO.BOTH,  timeout=400)
-    if channel is None:
-        print("Ultrasonic sensor timed out (post-echo).")
-        GPIO.remove_event_detect(ECHO)
-        restart()
-    # else:
-        # print("Echo finish detected")
-    stop = time.time()
-
-    elapsed = stop-start
-    distance = (elapsed * 34300)/2 # Using speed of sound at 20C (68F)
-
+    elapsed = stop - start
+    distance = (elapsed * 36000)/2
     return distance
 
-def restart():
-    # print("Restarting...")
-    GPIO.setmode(GPIO.BOARD)        # Use GPIO BOARD numbers
-    GPIO.setup(TRIGGER, GPIO.OUT)   # Trigger
-    GPIO.output(TRIGGER, False)     # Set low
-    GPIO.setup(ECHO, GPIO.OUT)      # Echo
-    GPIO.output(ECHO, False)
-    time.sleep(0.1)
-    GPIO.setup(ECHO,GPIO.IN)
-    GPIO.add_event_detect(ECHO, GPIO.BOTH)
-    time.sleep(2.0)
-
 # Main program loop
 if len(sys.argv) > 1:
     pins = sys.argv[1].lower().split(',')
@@ -70,7 +54,12 @@ if len(sys.argv) > 1:
     ECHO    = int(pins[1])
     SLEEP   = float(pins[2])
 
-    restart()
+    GPIO.setmode(GPIO.BOARD)        # Use GPIO BOARD numbers
+    GPIO.setup(TRIGGER, GPIO.OUT)   # Trigger
+    GPIO.output(TRIGGER, False)
+    GPIO.setup(ECHO, GPIO.OUT)      # Echo
+    GPIO.output(ECHO, False)
+    GPIO.setup(ECHO,GPIO.IN)
 
     # Flush stdin so we start clean
     while len(select.select([sys.stdin.fileno()], [], [], 0.0)[0])>0:
@@ -83,14 +72,12 @@ if len(sys.argv) > 1:
                 print(distance)
                 OLD = distance
             time.sleep(SLEEP)
-        except Exception as e:		# try to clean up on exit
-            print(e)			# Print error message on exception
-            GPIO.remove_event_detect(ECHO)
-            GPIO.cleanup(TRIGGER)
-            GPIO.cleanup(ECHO)
+        except:                     # try to clean up on exit
+            print("0.0")
+            GPIO.cleanup()
             sys.exit(0)
 
 else:
     print("Bad params")
-    print("    sudo nrsrf.py trigger_pin,echo_pin,rate_in_seconds")
+    print("    nrsrf.py trigger_pin, echo_pin, rate_in_seconds")
     sys.exit(0)

hardware/PiSrf/package.json

@@ -1,6 +1,6 @@
 {
     "name"          : "node-red-node-pisrf",
-    "version"       : "0.1.2",
+    "version"       : "0.1.3",
     "description"   : "A Node-RED node for a Raspberry Pi to use a SRF04 or SRF05 range finder",
     "dependencies"  : {
     },