I am writing a python script that will gather data from a serial port. I am able to gather the data and when it comes out it says b'1' I want to make an if statement for if it comes out as b'1' then I want it to run a function.
This is my code.
import serial
import time
z1baudrate = 115200
z1port = '/dev/ttyACM0'
z1serial = serial.Serial(port=z1port, baudrate=z1baudrate)
z1serial.timeout = 2
print (z1serial.is_open)
if z1serial.is_open:
while True:
size = z1serial.inWaiting()
if size:
data = z1serial.read(size)
print (data)
else:
print ("no data")
time.sleep(1)
else:
print("z1serial not open")
What should I do?
You can use "==" operator with bytes.
if z1serial.is_open == b'1':
...
should do the trick.
Related
So I have 2 python scripts, one is reading serial port data and the other is receiving a list from that data, however once I run the second script I get a permission error and can no longer read from the serial port. These are my 2 scripts and I'm doing stuff with Arduino, I know that I can have all this in 1 file but for latency purposes I separated the logic from the read. Here are my scripts:
read.py:
import serial
from time import sleep
ser = serial.Serial('COM7', 9600)
while True:
ser_bytes = ser.readline()
decoded_bytes = ser_bytes[0:len(ser_bytes)-2].decode('utf-8')
if len(decoded_bytes) == 0:
ser.flushInput()
if len(decoded_bytes) != 0:
find1 = decoded_bytes.find('&')
find2 = decoded_bytes.find('|')
find3 = decoded_bytes.find('/')
left = decoded_bytes[0:find1]
right = decoded_bytes[find1+1:find2]
fire = decoded_bytes[find2+1: find3]
jump = decoded_bytes[find3+1:]
keypresses = [left, right, fire, jump]
ser.flushInput()
do.py:
from read import keypresses
import pyautogui as pg
while True:
if keypresses[0] == 1:
pg.keyDown('a')
else:
pg.keyUp('a')
if keypresses[1] == 1:
pg.keyDown('d')
else:
pg.keyUp('d')
if keypresses[2] == 1:
pg.mouseDown()
else:
pg.mouseUp()
if keypresses[3] == 1:
pg.keyDown('w')
else:
pg.keyUp('w')
If you could help that'd be nice, thanks.
I am trying to read from two serial ports at once. Each connected device spits out a line of data. I read the data from each port as a list and then concatenate the list and print it out as one line.
If I read each port individually, the data updates fine. But the second I attempt to read from both, it lags up and the data stops changing in the print output. The timestamp updates fine, but the data itself is what starts to lag.
Below is my code, should I be doing some sort of threading? I am reading from an Arduino and a Teensy.
import serial
import time
serA = serial.Serial('/dev/arduino', 230400)
serT = serial.Serial('/dev/teensy', 9600)
while 1 :
timestamp = "%f" % time.time()
print(timestamp)
arduino = serA.readline().rstrip('\n')
data_listA = arduino.split('$')
teensy = serT.readline().rstrip('\n')
data_listT = teensy.split('$')
data_list = data_listA + data_listT
print(data_list)
just check to see if your serial port has bytes to read before you try to read it ...
while 1 :
timestamp = "%f" % time.time()
print(timestamp)
if serA.inWaiting(): # only read if there is something waiting to be read
arduino = serA.readline().rstrip('\n')
data_listA = arduino.split('$')
print("GOT ARDUINO:",data_listA)
if serB.inWaiting():
teensy = serT.readline().rstrip('\n')
data_listT = teensy.split('$')
print("GOT TEENSY:",data_listT)
Using inwaiting() unfortunately did not work for me. I ended up having to use threading. A basic example for people who might encounter my problem is shown below.
import serial
import Queue
import threading
queue = Queue.Queue(1000)
serA = serial.Serial('/dev/arduino', 230400)
serT = serial.Serial('/dev/teensy', 9600)
def serial_read(s):
while 1:
line = s.readline()
queue.put(line)
threadA = threading.Thread(target=serial_read, args=(serA,),).start()
threadT = threading.Thread(target=serial_read, args=(serT,),).start()
while 1:
line = queue.get(True, 1)
print line
I based my code on the last answer from this question.
I am making a throughput test for a bluetooth link, and I need to send data through a serial port to one bluetooth device which will then transport that data wirelessly to another bluetooth device. The other device will then complete the circuit by sending the data back to the host PC via a different serial port.
The problem seems to be when I attempt to open up 2 different instances of PySerial, the program simply hangs. I have isolated it down to running vs. hanging when I comment out one of the two serial port instantiations. Anyone see a problem with how I'm doing this? If so, what is the proper way to do this? See code below:
#/usr/bin/python
import serial
import time
import sys
DEFAULT_BAUD = 115200
SEND_SIZE = 100
def addPath(file):
pth, fl = os.path.split(__file__)
return os.path.join(pth, file)
def is_number(s):
try:
int(s, 16)
return True
except:
return False
class SerialReader():
def __init__(self, portRx, portTx):
self.portTx = portTx
self.portRx = portRx
self.start_time__sec = time.time()
self.interval__sec = 0
self.buffer = []
self.sendtext = ''.join([str(i) for i in range(SEND_SIZE)])
# send first batch of data
self.portTx.write(self.sendtext)
def didDataArrive(self):
# Read port
self.buffer.extend(list(self.portRx.read(1024)))
# Step through the buffer byte and byte and see if the tick text
# is at the front.
while len(self.buffer) >= len(self.sendtext):
if self.buffer[:len(self.sendtext)] == self.sendtext:
# Discard the tick text
self.buffer = self.buffer[len(self.sendtext):]
# Record time
snapshot__sec = time.time()
self.interval__sec = snapshot__sec - self.start_time__sec
self.start_time__sec = snapshot__sec
# send more data
self.portTx.write(self.sendtext)
return True
else:
self.buffer.pop(0)
return False
def main(port1, port2, baudrate1 = DEFAULT_BAUD, baudrate2 = DEFAULT_BAUD):
try:
import serial
except:
traceback.print_exc()
print "="*60
print "You need to install PySerial"
print "Windows: easy_install pyserial"
print "Mac/Linux: sudo easy_install pyserial"
try:
s1 = serial.Serial(port1, baudrate1, timeout = 0.1)
s2 = serial.Serial(port2, baudrate2, timeout = 0.1)
print "Loading serial ports"
except:
print "Serial port error"
exit()
plot_stop = False
dataread = SerialReader(s2, s1)
try:
while plot_stop == False:
if dataread.didDataArrive():
print dataread.interval__sec
except KeyboardInterrupt:
print "Keyboard Interrupt"
plot_stop = True
finally:
print "Closing"
s1.close()
s2.close()
if __name__ == '__main__':
if (len(sys.argv) < 3):
print "Usage: python extract_data.py phonelink_serialport phonelinkclient_serialport [baudrate1] [baudrate2]"
else:
main(*sys.argv[1:])
If I remove one of the following lines (doesn't matter which one), the python script runs (although it eventually crashes because in the code it eventually tries to reference both ports). If I leave these lines in, the program seems to just hang (it just seems to sit there and run indefinitely):
s1 = serial.Serial(port1, baudrate1, timeout = 0.1)
s2 = serial.Serial(port2, baudrate2, timeout = 0.1)
I'm using PySerial to read from serial port like in the code below.
CheckReadUntil() read output of the command that I send to serial port until the sequence of symbols readUntil are in the serial output.
...
self.ser = serial.Serial(comDev, 115200, timeout=10)
...
#Function that continue to read from Serial port until 'readUntil'
#sequence of symbols appears
def CheckReadUntil(self, readUntil):
outputCharacters = []
while 1:
ch = self.ser.read()
outputCharacters += ch
if outputCharacters[-len(readUntil):]==readUntil:
break
outputLines = ''.join(outputCharacters)
return outputLines
However, if there is no sequence readUntil (for any reason), I'm just stuck in the function CheckReadUntil() forever. The setting timeout=10 sets up timeout so I'm stuck in a loop that iterates every 10 seconds and does nothing, just waiting.
How it is possible to understand that there was a timeout event so I may exit the infinite loop? Output length may be different.
UPDATE (previous answer was not correct, this is the working code from #konstantin):
...
self.ser = serial.Serial(comDev, 115200, timeout=10)
...
#Function that continue to read from Serial port until 'readUntil'
#sequence of symbols appears
def CheckReadUntil(self, readUntil):
outputCharacters = []
while 1:
ch = self.ser.read()
if len(ch) == 0:
break
outputCharacters += ch
if outputCharacters[-len(readUntil):]==readUntil:
break
outputLines = ''.join(outputCharacters)
return outputLines
As a newbie to python, I'm trying to use it to read a file and write each line of the file to the RS-232 port. My code bellow seems to work for the most part, except for my listen and react segments. From poking around, it seems that my if statements can't read if I've received a "Start\r", or "End\r" string from my device (RS-232). Can anyone provide feedback on what is missing?
import serial
import time
port = "/dev/ttyS0"
speed = 9600
print("\n\n\n\nScript Starting\n\n\n")
ser = serial.Serial(port, speed, timeout=0)
ser.flushInput() #flush input buffer, discarding all its contents
ser.flushOutput()#flush output buffer, aborting current output and discard all that is in buffer
text_file = open("my.file", "r")
lines = text_file.read().split('\n')
i = 0
counter = 0
while i<len(lines):
response = ser.readline()
if (counter == 0):
print("\n\nProbing With Off Data\n")
ser.write('FFF')
ser.write('\r')
counter+=1
if (response == 'Start'):
ser.write('FFF')
ser.write('\r')
if (response == 'End'):
print("\nString Transmitted:")
print lines
make_list_a_string = ''.join(map(str, lines))
ser.write(make_list_a_string)
ser.write('\r')
print("\n")
i+=1
text_file.close()
exit(0)
Try using strip() to get rid of any trailing or preceding '\r's:
if (response.strip() == 'Start'):