Merge branch 'dfluff-master'

Author: Gadgetoid

examples/bargraph.py

@@ -0,0 +1,120 @@
+#!/usr/bin/env python
+
+from icm20948 import ICM20948
+import time
+import math
+import argparse
+import os
+import signal
+import sys
+
+BAR_CHAR = u'\u2588'  # Unicode FULL BLOCK
+
+running = True
+mingraphval = 0
+maxgraphval = 360
+
+
+# Terminal bar-graph adapted from examples/graph.py file from
+# https://github.com/pimoroni/vl53l1x-python
+def graphValue(value):
+    global cols, mingraphval, maxgraphval
+    if value > maxgraphval:
+        value = maxgraphval
+    elif value < mingraphval:
+        value = mingraphval
+
+    graphvalue = value - mingraphval
+
+    bar_size = int((graphvalue / float(maxgraphval - mingraphval)) * (cols - 10))  # Scale bar_size to our terminal width
+    bar = BAR_CHAR * bar_size        # Create a bar out of `bar_size` unicode FULL BLOCK characters
+    bar = bar.ljust(cols - 7, u' ')  # Pad the bar to the full with of the terminal, minus the value prefix
+    sys.stdout.write("\r")           # Return the cursor to the beginning of the current line
+    sys.stdout.write(u"{:05.1f} {}".format(value, bar))  # Output our measurement and bar
+    sys.stdout.flush()               # Flush the output buffer, since we're overdrawing the last line
+
+
+def exit_handler(signal, frame):
+    global running, args
+    running = False
+    if args.graph:
+        # Clean up terminal after using --graph output
+        sys.stdout.write("\n")
+    sys.exit(0)
+
+
+signal.signal(signal.SIGINT, exit_handler)
+
+parser = argparse.ArgumentParser()
+parser.add_argument('--axis', choices=['xy', 'yz', 'xz'], default='yz', help="Axis to measure (default: yz)")
+parser.add_argument('--graph', '-g', action="store_true", default=False, help="Display heading as terminal-graph")
+args = parser.parse_args()
+
+
+if args.graph:
+    try:
+        rows, cols = [int(c) for c in os.popen("stty size", "r").read().split()]
+    except ValueError:
+        print("Cannot get size of tty! Try running in Terminal.")
+        sys.exit(1)
+
+
+print("""bargraph.py - Convert raw values to heading
+
+Rotate the sensor through 360 degrees to calibrate.
+
+Press Ctrl+C to exit!
+
+""")
+
+X = 0
+Y = 1
+Z = 2
+
+if args.axis == 'xy':
+    AXES = X, Y
+elif args.axis == 'yz':
+    AXES = Y, Z
+elif args.axis == 'xz':
+    AXES = X, Z
+
+
+if args.graph:
+    sys.stdout.write("\n")
+
+
+imu = ICM20948()
+
+amin = list(imu.read_magnetometer_data())
+amax = list(imu.read_magnetometer_data())
+
+while running:
+    mag = list(imu.read_magnetometer_data())
+    for i in AXES:
+        v = mag[i]
+        if v < amin[i]:
+            amin[i] = v
+        if v > amax[i]:
+            amax[i] = v
+        mag[i] -= amin[i]
+        try:
+            mag[i] /= amax[i] - amin[i]
+        except ZeroDivisionError:
+            pass
+        mag[i] -= 0.5
+
+    heading = math.atan2(mag[AXES[0]], mag[AXES[1]])
+
+    if heading < 0:
+        heading += 2 * math.pi
+    heading = math.degrees(heading)
+
+    if args.graph:
+        # Display the heading as a bar-graph in the terminal
+        graphValue(heading)
+    else:
+        # Round the heading value and print out directly
+        heading = round(heading)
+        print("Heading: {}".format(heading))
+
+    time.sleep(0.1)