rpOsci: re-introduced legend chan1, chan2

rpOsci.py

@@ -368,8 +368,11 @@ class OscDisplay(QWidget, Ui_OscDisplay):
         self.ax_y2.set_ylabel("Voltage [mV]", color='grey', size='x-large')
         # gq end
         x = np.arange(self.tot)
-        (self.curve2,) = self.ax.plot(x, self.buffer[1::2], color="#00CCCC")
-        (self.curve1,) = self.ax.plot(x, self.buffer[0::2], color="#FFAA00")
+        (self.curve2,) = self.ax.plot(x, self.buffer[1::2],
+                                      color="#00CCCC", label="chan 2")
+        (self.curve1,) = self.ax.plot(x, self.buffer[0::2],
+                                      color="#FFAA00", label="chan 1")
+        self.ax.legend(handles=[self.curve1, self.curve2])
         self.line = [None, None]
         self.line[0] = self.ax.axvline(self.pre, linestyle="dotted")
         self.line[1] = self.ax.axhline(self.levelValue.value(), linestyle="dotted")