Startup

script/devices/BarcodeReader.py

@@ -0,0 +1,83 @@
+
+
+class BarcodeReader(DeviceBase):
+
+    def __init__(self, name, microscan, microscan_cmd):
+        DeviceBase.__init__(self, name)
+        self.microscan = microscan
+        self.microscan_cmd = microscan_cmd
+
+        
+    def doInitialize(self):
+        self.disable()
+        self.readout = None
+        self.processing = False
+        self.task_callable=None
+        
+    def enable(self):
+        self.microscan_cmd.write("<H>")
+        self.setState(State.Ready)
+    
+    def disable(self):    
+        self.microscan_cmd.write("<I>")
+        self.setState(State.Disabled)
+    
+    def get(self,timeout=1.0):    
+        self.state.assertReady()
+        try:
+            self.setState(State.Busy)
+            self.microscan.flush()
+            ret =  self.microscan.waitString(int(timeout * 1000)) 
+            if ret is not None:
+                ret = ret.strip()   
+            self.setCache(ret, None)
+            return ret
+        except:
+            self.setCache(None, None)
+            return None
+        finally:
+            if self.state == State.Busy:
+                self.setState(State.Ready)
+
+    def doUpdate(self):
+        self.get()
+
+
+    def read(self,timeout=1.0):    
+        if self.processing:
+            raise Exception("Ongoing read operation")
+        self.processing = True
+        try:
+            initial = self.state
+            if initial == State.Disabled:
+                self.enable()
+            try:
+                return self.get(timeout)
+            finally:
+                if initial == State.Disabled:
+                    self.disable()
+        finally:
+            self.processing = False
+    
+    def _read_task(self, timeout):
+        global readout
+        self.readout = self.read(timeout)
+        return self.readout
+    
+    def start_read(self, timeout=1.0):
+        self.readout = None
+        self.task_callable = fork((self._read_task, (timeout,)))   
+
+    def get_readout(self):
+        return self.readout
+
+    def wait_readout(self):
+        if self.task_callable is not None:
+            join(self.task_callable)
+            self.task_callable = None
+        return self.readout
+
+
+add_device(BarcodeReader("barcode_reader", mscan_pin, mscan_pin_cmd), force = True)         
+add_device(BarcodeReader("barcode_reader_puck", mscan_puck, mscan_puck_cmd), force = True)         
+