Python Serial Plotter

FastSerialPlotter.md

Python Serial Plotter High Frequency UART Plot AVR Arduino

This code plots serial data using mathplotlib and with high frequency. You might use it as a crude oscilloscope

import serial
from threading import Thread
import threading
import time
import matplotlib.pyplot as plt
import matplotlib.animation as animation
import numpy as np

serialPort = "/dev/ttyUSB0"
serialBaud = 115200

print('Trying to connect to: ' + str(serialPort) +
      ' at ' + str(serialBaud) + ' BAUD.')
serialConnection = serial.Serial(serialPort, serialBaud, timeout=4)
print('Connected')

plotXSize = 10000
isRun = True
serialData = []
plotData = list(range(-plotXSize, 1024+1))[-plotXSize:]

serialDataLock = threading.Lock()


def readerThreadWorker():
    global plotData, serialData
    time.sleep(1.0)
    while (isRun):
        time.sleep(0.1)
        serialDataLock.acquire()
        data = serialData.copy()
        serialData = []
        serialDataLock.release()
        if len(data) == 0:
          continue
        plotData.extend(data)
        plotData = plotData[-plotXSize:]
        print(len(data) / 0.1, "Data/Second")


def writerThreadWorker():
    global serialData
    time.sleep(1.0)
    serialConnection.reset_input_buffer()
    while (isRun):
        data = serialConnection.readline()[:-1]
        data = int(str(data, 'utf-8', 'ignore'))
        serialDataLock.acquire()
        serialData.append(data)
        serialDataLock.release()


writerThread = Thread(target=writerThreadWorker)
writerThread.start()
readerThread = Thread(target=readerThreadWorker)
readerThread.start()


x = list(range(1, plotXSize+1))
y = plotData

# You probably won't need this if you're embedding things in a tkinter plot...
plt.ion()

fig = plt.figure()
ax = fig.add_subplot(111)
line1, = ax.plot(x, y)  # Returns a tuple of line objects, thus the comma

while 1:
    line1.set_ydata(np.array(plotData))
    ax.set_ylim([max(0,min(plotData)), max(plotData)])
    fig.canvas.draw()
    fig.canvas.flush_events()
    time.sleep(0.1)