Fix stop readout #162

This addresses issue #162 (closed).

The stop_readout function is fixed and now called in scan_ext_trigger.py. Additionally, the readout contextmanager was fixed, as indicated by @jjanssen. Thank you again!

bdaq53/scan_base.py

@@ -581,9 +581,10 @@ class ScanBase(object):
             self.chip.wait_for_aurora_sync()
 
         self.start_readout(*args, **kwargs)
-        yield
-        self.fifo_readout.stop(timeout=timeout)
-
+        try:
+            yield
+        finally:
+            self.stop_readout(timeout=timeout)
 
     def start_readout(self, scan_param_id=0, *args, **kwargs):
         # Pop parameters for fifo_readout.start
@@ -597,6 +598,9 @@ class ScanBase(object):
         self.fifo_readout.start(reset_sram_fifo=reset_sram_fifo, fill_buffer=fill_buffer, clear_buffer=clear_buffer,
                                 callback=callback, errback=errback, no_data_timeout=no_data_timeout)
 
+    def stop_readout(self, timeout=10.0):
+        self.fifo_readout.stop(timeout=timeout)
+
     def handle_data(self, data_tuple):
         '''
             Handling of the data.