Read and write value of the characteristic

[stefan85e]

Connect to a BLE Device and Retrieve Data

I trying this ex: https://docs.pycom.io/chapter/tutorials/all/ble.html
I wounder what should I do to write data so that this code that is in this ex: can read it?

characteristic.read()
Read the value of the characteristic, sending a request to the GATT server. Returns a bytes object representing the characteristic value.

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)