ทดสอบทำ Data Visualization โดยรับค่าจาก Serial Port นำมาแสดงผลด้วย matplotlib บน Python Platform
Library ที่จำเป็น
- matplotlib-1.3.1.win-amd64-py2.7
- numpy-MKL-1.8.1.win-amd64-py2.7
- pyparsing-2.0.2.win-amd64-py2.7
- pyserial-2.7.win-amd64-py2.7
- python-dateutil-2.2.win-amd64-py2.7
- six-1.6.1.win-amd64-py2.7
สามารถดาวน์โหลดได้ที่ http://www.lfd.uci.edu/~gohlke/pythonlibs/#six
Python ดาวน์โหลดได้ที่ https://www.python.org/
Arduino Sketch
int i = 0;
void setup() {
// initialize serial communication at 9600 bits per second:
Serial.begin(9600);
}
// the loop routine runs over and over again forever:
void loop() {
do {
i = i+1;
Serial.println(i);
delay(1);
}
while(i < 5);
do {
i = i-1;
Serial.println(i);
delay(1);
}
while(i > 0);
delay(1); // delay in between reads for stability
}
Python Code
import sys, time
import numpy as np
from matplotlib import pyplot as plt
from serial import Serial
from serial import SerialException
## specify your serial port here
## for Ubuntu: use '/dev/ttyUSB0' or '/dev/ttyACM0'
com_port = 'COM1'
## specify baudrate
baudrate = 9600
timeout = 1.0 # set serial I/O timeout in seconds
try:
ser = Serial( port=com_port, baudrate=baudrate, timeout=timeout,
bytesize=8, parity='N', stopbits=1 )
except SerialException as ex:
print ex
sys.exit(-1)
nsteps = 200
ymax = 5.5
ymin = 0.0
xdata = []
ydata = []
fig, ax = plt.subplots()
data, = ax.plot( xdata, ydata )
plt.axis( [0,nsteps,ymin,ymax] )
plt.ion() # enable interactive plotting mode
plt.title('Arduino Serial Plot')
plt.xlabel('Index')
plt.ylabel('Data')
plt.grid(True)
plt.show(block=False)
x = 0
new_y = []
print 'Press Ctrl+C to exit...'
try:
while True:
y = ser.readline()
if y is None or len(y) == 0:
continue
##y = int(y.strip()) / 1000.0
new_y.append( y )
if len(new_y) < 10:
continue
for y in new_y:
ydata.append(y)
xdata.append(x)
x += 1
new_y = []
if len(xdata) > nsteps:
n = len(xdata)-nsteps
del xdata[0:n]
del ydata[0:n]
plt.xlim( [x-nsteps+1,x] )
else:
plt.xlim( [0,nsteps] )
data.set_data( xdata, ydata )
#fig.canvas.draw()
fig.canvas.flush_events()
except KeyboardInterrupt as ex:
print 'Exit'
except Exception as ex:
print 'Exception:', ex
finally:
print 'Done...'
pass
sys.exit(0)
Serial Port
Reviewed by Uthid
on
December 01, 2020
Rating:
Reviewed by Uthid
on
December 01, 2020
Rating:
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