pycom-documentation/content/tutorials/networks/ble.md

title, aliases

title	aliases
Bluetooth	tutorials/all/ble.html tutorials/all/ble.md chapter/tutorials/all/ble

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.

Scan for BLE devices

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 ubinascii
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(ubinascii.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)

Connect to a BLE device and get name and manufacturer data

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

import ubinascii
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(ubinascii.hexlify(mfg_data))