SERIAL之 READLINE READ_UNTIL比较

最新推荐文章于 2024-12-18 07:29:58 发布

原创最新推荐文章于 2024-12-18 07:29:58 发布 · 1.9k 阅读

0 ·

CC 4.0 BY-SA版权

PYTHON 专栏收录该内容

67 篇文章

订阅专栏

本文介绍了一种使用Python进行串口通信的方法，通过测试readline和read_until函数在不同timeout设置下的表现，对比了阻塞型和非阻塞型读取方式的差异。

部署运行你感兴趣的模型镜像

READLINE

阻塞型，除非设置了timeout

READ_UNTIL

非阻塞型，最好设置timeout

# test serial timeout, readline and read_until
import time
import serial
import serial.tools.list_ports

def get_time_stamp():
   ct = time.time()
   local_time = time.localtime(ct)
   data_head = time.strftime("%Y-%m-%d %H:%M:%S", local_time)
   data_secs = (ct - int(ct)) * 1000
   time_stamp = "%s.%03d" % (data_head, data_secs)
   return time_stamp


port_list = list(serial.tools.list_ports.comports())
#print(port_list)
if len(port_list) == 0:
   print('无可用串口')
else:
   for i in range(0,len(port_list)):
       #help(port_list[i])
       #print(port_list[i].__dict__)
       #print(port_list[i])
       port_name = port_list[i].device

tout = 0.1
#print(port_name)
#print(type(port_name))

###############################test readline function##########################################
try:
   serial_timeout = serial.Serial(port_name,115200,timeout=tout)
except Exception as e:
   print('rasie exception:',e)
   
try:
   serial_timeout.open()
except:
   print(port_name,' has opened! ')
   
print('start test readline.........',get_time_stamp())

#write serial
try:
   serial_timeout.write(b'II\n')
except Exception as e:
   print(e)
#read serial
try:
   serial_timeout.readline()
except Exception as e:
   print(e)
   
#serial_timeout.close()
print('stop test readline.........',get_time_stamp())


###############################test readline function##########################################

#serial_timeout = serial.Serial(port_name,115200,timeout=tout)

try:
   serial_timeout = serial.Serial(port_name,115200,timeout=tout)
except Exception as e:
   print('rasie exception:',e)
   
   
try:
   serial_timeout.open()
except:
   print(port_name,' has opened! ')
   
print('start test read_until.........',get_time_stamp())

#write serial
try:
   serial_timeout.write(b'II\n')
except Exception as e:
   print(e)
#read serial
try:
   serial_timeout.read_until(b'\n\n')
except Exception as e:
   print(e)
   
serial_timeout.close()
print('stop test read_until.........',get_time_stamp())