Turn BLE: Implementing BLE Sensors with MCU Devkits

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from machine import Pin

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led = Pin('LED', Pin.OUT)

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while True:
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  led.toggle()

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import time
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while True:
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  time.sleep_ms(500)

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from machine import ADC

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adc = ADC(4)

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temperature =  27.0 - ((adc.read_u16() * 3.3 / 65535) - 0.706) / 0.001721
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print("T: {}ºC".format(temperature))

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import aioble
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import bluetooth

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# Constants for the device information service
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_SVC_DEVICE_INFO = bluetooth.UUID(0x180A)
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svc_dev_info = aioble.Service(_SVC_DEVICE_INFO)

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_CHAR_MANUFACTURER_NAME_STR = bluetooth.UUID(0x2A29)
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_CHAR_MODEL_NUMBER_STR = bluetooth.UUID(0x2A24)
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_CHAR_SERIAL_NUMBER_STR = bluetooth.UUID(0x2A25)
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_CHAR_FIRMWARE_REV_STR = bluetooth.UUID(0x2A26)
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_CHAR_HARDWARE_REV_STR = bluetooth.UUID(0x2A27)
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aioble.Characteristic(svc_dev_info, _CHAR_MANUFACTURER_NAME_STR, read=True, initial='Jorge')
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aioble.Characteristic(svc_dev_info, _CHAR_MODEL_NUMBER_STR, read=True, initial='J-0001')
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aioble.Characteristic(svc_dev_info, _CHAR_SERIAL_NUMBER_STR, read=True, initial='J-0001-0000')
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aioble.Characteristic(svc_dev_info, _CHAR_FIRMWARE_REV_STR, read=True, initial='0.0.1')
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aioble.Characteristic(svc_dev_info, _CHAR_HARDWARE_REV_STR, read=True, initial='0.0.1')

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aioble.register_services(svc_dev_info)

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from micropython import const
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_ADVERTISING_INTERVAL_US = const(200_000)
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_APPEARANCE = const(0x0552) # Multi-sensor
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async def task_peripheral():
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  """ Task to handle advertising and connections """
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  while True:
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    async with await aioble.advertise(
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        _ADVERTISING_INTERVAL_US,
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        name='RP2-SENSOR',
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        appearance=_APPEARANCE,
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        services=[_DEVICE_INFO_SVC]
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    ) as connection:
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      print("Connected from ", connection.device)
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      await connection.disconnected() # NOT connection.disconnect()
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      print("Disconnect")

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connected=False
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async def task_peripheral():
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  """ Task to handle advertising and connections """
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  global connected
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  while True:
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    connected = False
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    async with await aioble.advertise(
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        _ADVERTISING_INTERVAL_MS,
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        appearance=_APPEARANCE,
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        name='RP2-SENSOR',
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        services=[_SVC_DEVICE_INFO]
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    ) as connection:
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      print("Connected from ", connection.device)
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      connected = True

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async def task_flash_led():
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  """ Blink the on-board LED, faster if disconnected and slower if connected  """
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  BLINK_DELAY_MS_FAST = const(100)
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  BLINK_DELAY_MS_SLOW = const(500)
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  while True:
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    led.toggle()
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    if connected:
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      await asyncio.sleep_ms(BLINK_DELAY_MS_SLOW)
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    else:
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      await asyncio.sleep_ms(BLINK_DELAY_MS_FAST)

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import uasyncio as asyncio

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async def task_sensor():
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  """ Task to handle sensor measures """
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  while True:
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    temperature =  27.0 - ((adc.read_u16() * 3.3 / 65535) - 0.706) / 0.001721
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    print("T: {}°C".format(temperature))
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    time.sleep_ms(_TEMP_MEASUREMENT_INTERVAL_MS)

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_TEMP_MEASUREMENT_INTERVAL_MS = const(15_000)

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await asyncio.sleep_ms(_TEMP_MEASUREMENT_FREQUENCY)

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async def main():
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  """ Create all the tasks """
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  tasks = [
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    asyncio.create_task(task_peripheral()),
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    asyncio.create_task(task_flash_led()),
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    asyncio.create_task(task_sensor()),
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  ]
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  asyncio.gather(*tasks)

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asyncio.run(main())

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# Constants for the Environmental Sensing Service
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_SVC_ENVIRONM_SENSING = bluetooth.UUID(0x181A)
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svc_env_sensing = aioble.Service(_SVC_ENVIRONM_SENSING)

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_CHAR_TEMP_MEASUREMENT = bluetooth.UUID(0x2A1C)
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temperature_char = aioble.Characteristic(svc_env_sensing, _CHAR_TEMP_MEASUREMENT, read=True)

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aioble.register_services(svc_dev_info, svc_env_sensing)

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services=[_SVC_DEVICE_INFO, _SVC_ENVIRONM_SENSING]

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def _encode_ieee11073(value, precision=2):
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  """ Binary representation of float value as IEEE-11073:20601 32-bit FLOAT """
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  return int(value * (10 ** precision)).to_bytes(3, 'little', True) + struct.pack('<b', -precision)

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temperature_char.write(struct.pack("<B4s", 0, _encode_ieee11073(temperature)))

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await connection.disconnected(timeout_ms=None)

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temperature_char = aioble.Characteristic(svc_env_sensing, _CHAR_TEMP_MEASUREMENT, read=True, notify=True)

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_DESC_ES_TRIGGER_SETTING = bluetooth.UUID(0x290D)
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aioble.Descriptor(temperature_char, _DESC_ES_TRIGGER_SETTING, write=True, initial=struct.pack("<B", 0))

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connection = None

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global connected, connection

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connection = None

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payload = struct.pack("<B4s", 0, _encode_ieee11073(temperature))
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temperature_char.write(payload)
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if connection is not None:
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  temperature_char.notify(connection, payload)