ble_temperature.py

# Questo lavoro è concesso in licenza MIT.
# Copyright (c) 2013-2023 OpenMV LLC. Tutti i diritti riservati.
# https://github.com/openmv/openmv/blob/master/LICENSE
#
# Esempio di sensore di temperatura BLE.

import time
from hts221 import HTS221
from board import LED
from machine import Pin, I2C
from ubluepy import Service, Characteristic, UUID, Peripheral, constants


def event_handler(id, handle, data):
    global periph, service, notif_enabled

    if id == constants.EVT_GAP_CONNECTED:
        # indica 'connesso'
        LED(1).on()
    elif id == constants.EVT_GAP_DISCONNECTED:
        # indica 'disconnesso'
        LED(1).off()
        # riavvia l'advertisement
        periph.advertise(device_name="Temperature Sensor", services=[service])
    elif id == constants.EVT_GATTS_WRITE:
        # la scrittura su questa Characteristic è verso il CCCD
        if int(data[0]) == 1:
            notif_enabled = True
        else:
            notif_enabled = False


# inizia con LED(1) spento
LED(1).off()

notif_enabled = False
uuid_service = UUID("0x181A")  # Servizio Environmental Sensing
uuid_temp = UUID("0x2A6E")  # Characteristic di temperatura

service = Service(uuid_service)
temp_props = Characteristic.PROP_READ | Characteristic.PROP_NOTIFY
temp_attrs = Characteristic.ATTR_CCCD
temp_char = Characteristic(uuid_temp, props=temp_props, attrs=temp_attrs)
service.addCharacteristic(temp_char)

periph = Peripheral()
periph.addService(service)
periph.setConnectionHandler(event_handler)
periph.advertise(device_name="Temperature Sensor", services=[service])

bus = I2C(1, scl=Pin(15), sda=Pin(14))
try:
    hts = HTS221(bus)
except OSError:
    from hs3003 import HS3003

    hts = HS3003(bus)

while True:
    if notif_enabled:
        temp = int(hts.temperature() * 100)
        temp_char.write(bytearray([temp & 0xFF, temp >> 8]))
    time.sleep_ms(100)