add emg_rate.py example

examples/emg_rate.py

@@ -0,0 +1,77 @@
+# Copyright (c) 2015  Niklas Rosenstein
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+import sys
+import myo as libmyo
+from time import clock
+from collections import deque
+
+
+class EmgRate(libmyo.DeviceListener):
+
+  __slots__ = 'times last_time n'.split()
+
+  def __init__(self, n):
+    super(EmgRate, self).__init__()
+    self.times = deque()
+    self.last_time = None
+    self.n = int(n)
+
+  @property
+  def rate(self):
+    if not self.times:
+      return 0.0
+    else:
+      return 1.0 / (sum(self.times) / float(self.n))
+
+  def on_pair(self, myo, *args):
+    print("on_pair")
+
+  def on_connect(self, myo, *args):
+    print("on_connect")
+
+  def on_arm_sync(self, myo, *args):
+    print("on_arm_sync")
+    myo.set_stream_emg(libmyo.StreamEmg.enabled)
+
+  def on_emg_data(self, myo, timestamp, emg):
+    t = clock()
+    if self.last_time is not None:
+      self.times.append(t - self.last_time)
+      if len(self.times) > self.n:
+        self.times.popleft()
+    self.last_time = t
+
+def main():
+  libmyo.init()
+  hub = libmyo.Hub()
+  listener = EmgRate(50)
+  try:
+    while True:
+      hub.run_once(100, listener)
+      print("\r\033[KEMG Rate:", listener.rate, end='')
+      sys.stdout.flush()
+  finally:
+    hub.stop(True)
+    hub.shutdown()
+
+
+if __name__ == '__main__':
+  main()