树莓派ZeroW串口通讯

  1 # -*- coding:utf-8 -*-
  2 import serial
  3 import time
  4 
  5 def main():
  6   ser = serial.Serial("/dev/ttyAMA0", 19200)
  7   ser.flushInput()
  8   ser.flushOutput()
  9 
 10   while True:
 11     recv_num = ser.inWaiting()
 12 
 13     if recv_num > 0:
 14       recv_buffer = ser.read(recv_num)
 15       ser.flushInput()
 16 
 17       ser.flushOutput()
 18       ser.write('received ' + str(recv_num) + ' bytes >>  ')
 19       ser.write(recv_buffer)
 20 
 21     time.sleep(0.1)
 22 
 23 if __name__ == '__main__':
 24   main()

  1 # -*- coding:utf-8 -*-
  2 import serial
  3 import time
  4 import binascii
  5 
  6 DB_COMN_LENGTH = 400
  7 COMN_LENTH_MIN = 50
  8 COMN_LENTH_MAX = 400
  9 
 10 def DeviceConfigSet(str_config):
 11   print('DeviceConfigSet() function run...')
 12 
 13 def DeviceClear():
 14   print('DeviceClear() function run...')
 15 
 16 def GetDeviceStatus():
 17   print('GetDeviceStatus() function run...')
 18   return 'defined_device_status_string...'
 19 
 20 def main():
 21   global DB_COMN_LENGTH
 22   global COMN_LENTH_MIN
 23   global COMN_LENTH_MAX
 24 
 25   # initialize
 26   print('>> initialize...')
 27   ####
 28 
 29   is_data_received = False
 30   is_admin_mode_enabled = False
 31 
 32   in_admin_count = 0
 33   update_status_interval = 0
 34 
 35   comn_data = [0 for i in range(DB_COMN_LENGTH)]
 36   recv_num_last = 0
 37 
 38   ser = serial.Serial("/dev/ttyAMA0",19200)
 39   ser.flushInput()
 40   ser.flushOutput()
 41 
 42   print('>> wait for data or command...')
 43 
 44   while True:
 45     recv_num = ser.inWaiting()
 46     if recv_num > 0:
 47       time.sleep(0.01)
 48       recv_num_real = ser.inWaiting()
 49       while recv_num_real > recv_num:
 50         recv_num = recv_num_real
 51         time.sleep(0.01)
 52         recv_num_real = ser.inWaiting()
 53 
 54       recv = ser.read(recv_num_real)
 55 
 56       if in_admin_count < 3600 and 'ADMIN_CONFIG' == recv[0:12]:
 57         print('>> command received...')
 58         print(recv)
 59         is_admin_mode_enabled = True
 60         DeviceConfigSet(recv)
 61 
 62       elif in_admin_count < 3600 and 'ADMIN_QUERY*' == recv[0:12]:
 63         print('>> command received...')
 64         print(recv)
 65         is_admin_mode_enabled = True
 66 
 67       elif in_admin_count < 3600 and 'ADMIN_CLEAR*' == recv[0:12]:
 68         print('>> command received...')
 69         print(recv)
 70         is_admin_mode_enabled = True
 71         DeviceClear()
 72 
 73       elif True == is_admin_mode_enabled and 'ADMIN_EXIT**' == recv[0:12]:
 74         print('>> command received...')
 75         print(recv)
 76         is_admin_mode_enabled = False
 77 
 78       elif recv_num_real >= COMN_LENTH_MIN and recv_num_real <= COMN_LENTH_MAX:
 79         is_data_received = True
 80         for i in range(0, recv_num_real):
 81           comn_data[i] = int(binascii.b2a_hex(recv[i]), 16)
 82         for i in range(recv_num_real, recv_num_last):
 83           comn_data[i] = 0
 84         recv_num_last = recv_num_real
 85         print('>> data received...')
 86         print(comn_data)
 87 
 88       else:
 89         print('>> invalid data received!!!...')
 90         print(recv)
 91 
 92       ser.flushInput()
 93 
 94     # save data records if needed
 95     ####
 96 
 97     if in_admin_count < 3600:
 98       in_admin_count = in_admin_count + 1
 99     else:
100       is_admin_mode_enabled = False
101 
102     if True == is_admin_mode_enabled:
103       update_status_interval = update_status_interval + 1
104       if update_status_interval >= 20:
105         update_status_interval = 0
106         ser.flushOutput()
107         ser.write(GetDeviceStatus())
108 
109     # system tick
110     time.sleep(0.05)
111 
112 if __name__ == '__main__':
113   main()

  1 recv_num = ser.inWaiting()
  2 if recv_num > 0:
  3   time.sleep(0.01)
  4   recv_num_real = ser.inWaiting()
  5   while recv_num_real > recv_num:
  6     recv_num = recv_num_real
  7     time.sleep(0.01)
  8     recv_num_real = ser.inWaiting()
  9 
 10   recv = ser.read(recv_num_real)