bogus plotting script for IDE / Freescale cup car (replaces matlab script)

cam_plot.py

import numpy as np
import matplotlib.pyplot as plt
import serial

plt.ion()
fig = plt.figure()
ax1 = fig.add_subplot(3, 1, 1)
ax2 = fig.add_subplot(3, 1, 2)
ax3 = fig.add_subplot(3, 1, 3)

ax1.set_title("Raw Output")
ax2.set_title("5-Value Average Filter Output")
ax3.set_title("Binary Edge-Detector Output")

ax1.set_ylim([0, 65535])
ax2.set_ylim([0, 65535])
ax3.set_ylim([0, 2])

port = serial.Serial('/dev/ttyACM0', 9600)

scanline = [0]*128

avg_filter_scanlines = np.zeros(shape=(128, 5))
index = 0

raw, = ax1.plot(scanline)
average, = ax2.plot(scanline)
edge_detect, = ax3.plot(np.zeros(128))
idx = 0


def update_average(scan_array, idx):
    # avg_scanline = np.average(scan_array, axis=1)
    # np.roll(scan_array, idx, 1)
    n = 2
    h_n = [1/n]*n
    avg_scanline = np.convolve(scan_array[:, 0], h_n)
    return avg_scanline[0:128]


def update_edge_detect(average_scanline):
    output = np.abs(np.convolve(np.convolve(average_scanline, [-1, 0, 1]), [-1, 3, -1]))
    return output[0:128]/max(output)
    # THRESH = 4500
    # output = np.zeros(average_scanline.shape)
    # for i in range(0, average_scanline.shape[0]):
        # output[i] = 1 if average_scanline[i] > THRESH else 0

    # return output


def update_plots(scan_array, raw, average):
    raw.set_ydata(scan_array[:, 0])
    global idx
    # idx = (idx + 1) % avg_filter_scanlines.shape[1]
    avg = update_average(scan_array, idx)
    average.set_ydata(avg)
    edge_detect.set_ydata(update_edge_detect(avg))
    fig.canvas.draw()
    fig.canvas.flush_events()


port.reset_input_buffer()
port.flushInput()
while(True):
    a = port.readline().decode('utf-8').strip()
    try:
        a = int(a)
    except ValueError:
        print('conversion error')
        continue

    if a == -1:
        print(avg_filter_scanlines[:, 0])
        update_plots(avg_filter_scanlines, raw, average)
        index = 0
    elif index < 128:
        avg_filter_scanlines[index, 0] = a if a > 0 else 0
        index += 1
    else:
        print('extra data')
        port.flushInput()

    # plt.pause(0.000000000001)