1  # A more 'rugged' echo test for the Feather M0 Bluefruit
 2  # Sets the name, then echo's all RX'd data with a reversed packet
 3  # we wrap the loop in a try/except block and have multiple loops
 4  # and functions to keep our connection up and running no matter what
 5  
 6  import time
 7  import busio
 8  import board
 9  from digitalio import DigitalInOut
10  from adafruit_bluefruitspi import BluefruitSPI
11  
12  ADVERT_NAME = b"BlinkaBLE"
13  
14  spi_bus = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)
15  cs = DigitalInOut(board.D8)
16  irq = DigitalInOut(board.D7)
17  rst = DigitalInOut(board.D4)
18  bluefruit = BluefruitSPI(spi_bus, cs, irq, rst, debug=False)
19  
20  
21  def init_bluefruit():
22      # Initialize the device and perform a factory reset
23      print("Initializing the Bluefruit LE SPI Friend module")
24      bluefruit.init()
25      bluefruit.command_check_OK(b"AT+FACTORYRESET", delay=1)
26      # Print the response to 'ATI' (info request) as a string
27      print(str(bluefruit.command_check_OK(b"ATI"), "utf-8"))
28      # Change advertised name
29      bluefruit.command_check_OK(b"AT+GAPDEVNAME=" + ADVERT_NAME)
30  
31  
32  def wait_for_connection():
33      print("Waiting for a connection to Bluefruit LE Connect ...")
34      # Wait for a connection ...
35      dotcount = 0
36      while not bluefruit.connected:
37          print(".", end="")
38          dotcount = (dotcount + 1) % 80
39          if dotcount == 79:
40              print("")
41          time.sleep(0.5)
42  
43  
44  # This code will check the connection but only query the module if it has been
45  # at least 'n_sec' seconds. Otherwise it 'caches' the response, to keep from
46  # hogging the Bluefruit connection with constant queries
47  connection_timestamp = None
48  is_connected = None
49  
50  
51  def check_connection(n_sec):
52      # pylint: disable=global-statement
53      global connection_timestamp, is_connected
54      if (not connection_timestamp) or (time.monotonic() - connection_timestamp > n_sec):
55          connection_timestamp = time.monotonic()
56          is_connected = bluefruit.connected
57      return is_connected
58  
59  
60  # Unlike most circuitpython code, this runs in two loops
61  # one outer loop manages reconnecting bluetooth if we lose connection
62  # then one inner loop for doing what we want when connected!
63  while True:
64      # Initialize the module
65      try:  # Wireless connections can have corrupt data or other runtime failures
66          # This try block will reset the module if that happens
67          init_bluefruit()
68          wait_for_connection()
69          print("\n *Connected!*")
70  
71          # Once connected, check for incoming BLE UART data
72          while check_connection(3):  # Check our connection status every 3 seconds
73              # OK we're still connected, see if we have any data waiting
74              resp = bluefruit.uart_rx()
75              if not resp:
76                  continue  # nothin'
77              print("Read %d bytes: %s" % (len(resp), resp))
78              # Now write it!
79              print("Writing reverse...")
80              send = []
81              for i in range(len(resp), 0, -1):
82                  send.append(resp[i - 1])
83              print(bytes(send))
84              bluefruit.uart_tx(bytes(send))
85          print("Connection lost.")
86  
87      except RuntimeError as e:
88          print(e)  # Print what happened
89          continue  # retry!