make first version of liveplotter

tools/liveplotter.py

@@ -0,0 +1,41 @@
+#!/usr/bin/env python3
+"""
+Liveplotter
+"""
+
+import time
+import odrive.core
+import matplotlib.pyplot as plt
+import numpy as np
+import threading
+from IPython import embed
+
+data_rate = 100
+plot_rate = 10
+num_samples = 1000
+
+myOdrive = odrive.core.find_any()
+
+plt.ion()
+global vals
+vals = []
+
+def fetch_data():
+    global vals
+    while True:
+        vals.append(myOdrive.motor0.encoder.pll_pos)
+        if len(vals) > num_samples:
+            vals = vals[-num_samples:]
+        time.sleep(1/data_rate)
+
+def plot_data():
+    global vals
+    while True:
+        plt.clf()
+        plt.plot(vals)
+        plt.pause(1/plot_rate)
+
+fetch_thread = threading.Thread(target=fetch_data, daemon=True)
+fetch_thread.start()
+
+plot_data()