Bluetooth

At present, basic BLE functionality is available. More features will be implemented in the near future, such as pairing. This page will be updated in line with these features.

Full info on bluetooth can be found within bluetooth page of the Firmware API Reference.

Scan for BLE Devices

Scan for all of the advertising devices within range of the scanning device.

bluetooth.start_scan(10)        # starts scanning and stop after 10 seconds
bluetooth.start_scan(-1)        # starts scanning indefenitely until bluetooth.stop_scan() is called

Raw Data from a BLE Device

A quick usage example that scans and prints the raw data from advertisements.

from network import Bluetooth
bluetooth = Bluetooth()
bluetooth.start_scan(-1)    # start scanning with no timeout
while True:
    print(bluetooth.get_adv())

Connect to a BLE Device

Connecting to a device that is sending advertisements.

from network import Bluetooth
import binascii
bluetooth = Bluetooth()

# scan until we can connect to any BLE device around
bluetooth.start_scan(-1)
adv = None
while True:
    adv = bluetooth.get_adv()
    if adv:
        try:
            bluetooth.connect(adv.mac)
        except:
            # start scanning again
            bluetooth.start_scan(-1)
            continue
        break
print("Connected to device with addr = {}".format(binascii.hexlify(adv.mac)))

Connect to a BLE Device and Retrieve Data

Connecting to a device named ‘Heart Rate’ and receiving data from it’s services.

from network import Bluetooth
import time
bt = Bluetooth()
bt.start_scan(-1)

while True:
  adv = bt.get_adv()
  if adv and bt.resolve_adv_data(adv.data, Bluetooth.ADV_NAME_CMPL) == 'Heart Rate':
      try:
          conn = bt.connect(adv.mac)
          services = conn.services()
          for service in services:
              time.sleep(0.050)
              if type(service.uuid()) == bytes:
                  print('Reading chars from service = {}'.format(service.uuid()))
              else:
                  print('Reading chars from service = %x' % service.uuid())
              chars = service.characteristics()
              for char in chars:
                  if (char.properties() & Bluetooth.PROP_READ):
                      print('char {} value = {}'.format(char.uuid(), char.read()))
          conn.disconnect()
          break
      except:
          pass
  else:
      time.sleep(0.050)

Retrieve the Name & Manufacturer from a BLE Device

Using resolve_adv_data() to attempt to retrieve the name and manufacturer data from the advertiser.

import binascii
from network import Bluetooth
bluetooth = Bluetooth()

bluetooth.start_scan(20)
while bluetooth.isscanning():
    adv = bluetooth.get_adv()
    if adv:
        # try to get the complete name
        print(bluetooth.resolve_adv_data(adv.data, Bluetooth.ADV_NAME_CMPL))

        mfg_data = bluetooth.resolve_adv_data(adv.data, Bluetooth.ADV_MANUFACTURER_DATA)

        if mfg_data:
            # try to get the manufacturer data (Apple's iBeacon data is sent here)
            print(binascii.hexlify(mfg_data))