Merge pull request #249 from ajd4096/experimental-send-wait-timeout

Add optional wait timeout in milliseconds to printcore send, send_now

printcore.py

@@ -48,6 +48,7 @@ class printcore():
         self.onlinecb=None#impl ()
         self.loud=False#emit sent and received lines to terminal
         self.greetings=['start','Grbl ']
+        self.wait=0# default wait period for send(), send_now()
         if port is not None and baud is not None:
             #print port, baud
             self.connect(port, baud)
@@ -193,7 +194,7 @@ class printcore():
         self.printing=True
         Thread(target=self._print).start()
     
-    def send(self,command):
+    def send(self,command,wait=0):
         """Adds a command to the checksummed main command queue if printing, or sends the command immediately if not printing
         """
         
@@ -202,11 +203,18 @@ class printcore():
         else:
             while not self.clear:
                 time.sleep(0.001)
+            if (wait == 0 and self.wait > 0):
+                wait = self.wait
+            if (wait > 0)
+                self.clear=False
             self._send(command,self.lineno,True)
             self.lineno+=1
+            while ((wait > 0) and not self.clear):
+                time.sleep(0.001)
+                wait-=1
         
     
-    def send_now(self,command):
+    def send_now(self,command,wait=0):
         """Sends a command to the printer ahead of the command queue, without a checksum
         """
         if(self.online):
@@ -215,7 +223,14 @@ class printcore():
             else:
                 while not self.clear:
                     time.sleep(0.001)
+                if (wait == 0 and self.wait > 0):
+                    wait = self.wait
+                if (wait > 0)
+                    self.clear=False
                 self._send(command)
+                while ((wait > 0) and not self.clear):
+                    time.sleep(0.001)
+                    wait-=1
             #callback for command sent
         else:
             print "Not connected to printer."