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#1 2020-12-28 11:28:08

kekemuyu
会员
注册时间: 2018-12-13
累计积分: 610

微信小程序通过蓝牙采集温湿度

设备端是esp32+sht30,程序源码:

import bluetooth
from ble_advertising import advertising_payload

from micropython import const
from sht30 import SHT30
import json

sensor = SHT30()


_IRQ_CENTRAL_CONNECT = const(1)
_IRQ_CENTRAL_DISCONNECT = const(2)
_IRQ_GATTS_WRITE = const(3)

_UART_UUID = bluetooth.UUID("6E400001-B5A3-F393-E0A9-E50E24DCCA9E")
_UART_TX = (
    bluetooth.UUID("6E400003-B5A3-F393-E0A9-E50E24DCCA9E"),
    bluetooth.FLAG_NOTIFY,
)
_UART_RX = (
    bluetooth.UUID("6E400002-B5A3-F393-E0A9-E50E24DCCA9E"),
    bluetooth.FLAG_WRITE,
)
_UART_SERVICE = (
    _UART_UUID,
    (_UART_TX, _UART_RX,),
)

# org.bluetooth.characteristic.gap.appearance.xml
_ADV_APPEARANCE_GENERIC_COMPUTER = const(128)


class BLEUART:
    def __init__(self, ble, name="mpy-uart", rxbuf=100):
        self._ble = ble
        self._ble.active(True)
        self._ble.irq(handler=self._irq)
        ((self._tx_handle, self._rx_handle,),) = self._ble.gatts_register_services(
            (_UART_SERVICE,)
        )
        # Increase the size of the rx buffer and enable append mode.
        self._ble.gatts_set_buffer(self._rx_handle, rxbuf, True)
        self._connections = set()
        self._rx_buffer = bytearray()
        self._handler = None
        # Optionally add services=[_UART_UUID], but this is likely to make the payload too large.
        self._payload = advertising_payload(name=name, appearance=_ADV_APPEARANCE_GENERIC_COMPUTER)
        self._advertise()

    def irq(self, handler):
        self._handler = handler

    def _irq(self, event, data):
        # Track connections so we can send notifications.
        if event == _IRQ_CENTRAL_CONNECT:
            conn_handle, _, _, = data
            self._connections.add(conn_handle)
        elif event == _IRQ_CENTRAL_DISCONNECT:
            conn_handle, _, _, = data
            if conn_handle in self._connections:
                self._connections.remove(conn_handle)
            # Start advertising again to allow a new connection.
            self._advertise()
        elif event == _IRQ_GATTS_WRITE:
            conn_handle, value_handle, = data
            if conn_handle in self._connections and value_handle == self._rx_handle:
                self._rx_buffer += self._ble.gatts_read(self._rx_handle)
                if self._handler:
                    self._handler()

    def any(self):
        return len(self._rx_buffer)

    def read(self, sz=None):
        if not sz:
            sz = len(self._rx_buffer)
        result = self._rx_buffer[0:sz]
        self._rx_buffer = self._rx_buffer[sz:]
        return result

    def write(self, data):
        for conn_handle in self._connections:
            self._ble.gatts_notify(conn_handle, self._tx_handle, data)

    def close(self):
        for conn_handle in self._connections:
            self._ble.gap_disconnect(conn_handle)
        self._connections.clear()

    def _advertise(self, interval_us=500000):
        self._ble.gap_advertise(interval_us, adv_data=self._payload)


def demo():
    import time

    ble = bluetooth.BLE()
    uart = BLEUART(ble)

    def on_rx():
      print("rx: ", uart.read().decode().strip())

    uart.irq(handler=on_rx)
    
    #nums = [4, 8, 15, 16, 23, 42]
    #i = 0

    try:
        while True:
          temperature, humidity = sensor.measure()
          print('Temperature:', temperature, '℃, RH:', humidity, '%')
            #uart.write(str(nums[i]) + "\n")
          uart.write(json.dumps({"temp":'%.2f' % temperature}))  #ble max len 20 bytes
          uart.write(json.dumps({"humi":'%.2f' % humidity}))
          time.sleep_ms(1000)
    except KeyboardInterrupt:
        pass

    uart.close()


if __name__ == "__main__":
    demo()

ble_advertising.py

# Helpers for generating BLE advertising payloads.

from micropython import const
import struct
import bluetooth

# Advertising payloads are repeated packets of the following form:
#   1 byte data length (N + 1)
#   1 byte type (see constants below)
#   N bytes type-specific data

_ADV_TYPE_FLAGS = const(0x01)
_ADV_TYPE_NAME = const(0x09)
_ADV_TYPE_UUID16_COMPLETE = const(0x3)
_ADV_TYPE_UUID32_COMPLETE = const(0x5)
_ADV_TYPE_UUID128_COMPLETE = const(0x7)
_ADV_TYPE_UUID16_MORE = const(0x2)
_ADV_TYPE_UUID32_MORE = const(0x4)
_ADV_TYPE_UUID128_MORE = const(0x6)
_ADV_TYPE_APPEARANCE = const(0x19)


# Generate a payload to be passed to gap_advertise(adv_data=...).
def advertising_payload(limited_disc=False, br_edr=False, name=None, services=None, appearance=0):
    payload = bytearray()

    def _append(adv_type, value):
        nonlocal payload
        payload += struct.pack("BB", len(value) + 1, adv_type) + value

    _append(
        _ADV_TYPE_FLAGS,
        struct.pack("B", (0x01 if limited_disc else 0x02) + (0x18 if br_edr else 0x04)),
    )

    if name:
        _append(_ADV_TYPE_NAME, name)

    if services:
        for uuid in services:
            b = bytes(uuid)
            if len(b) == 2:
                _append(_ADV_TYPE_UUID16_COMPLETE, b)
            elif len(b) == 4:
                _append(_ADV_TYPE_UUID32_COMPLETE, b)
            elif len(b) == 16:
                _append(_ADV_TYPE_UUID128_COMPLETE, b)

    # See org.bluetooth.characteristic.gap.appearance.xml
    _append(_ADV_TYPE_APPEARANCE, struct.pack("<h", appearance))

    return payload


def decode_field(payload, adv_type):
    i = 0
    result = []
    while i + 1 < len(payload):
        if payload[i + 1] == adv_type:
            result.append(payload[i + 2 : i + payload[i] + 1])
        i += 1 + payload[i]
    return result


def decode_name(payload):
    n = decode_field(payload, _ADV_TYPE_NAME)
    return str(n[0], "utf-8") if n else ""


def decode_services(payload):
    services = []
    for u in decode_field(payload, _ADV_TYPE_UUID16_COMPLETE):
        services.append(bluetooth.UUID(struct.unpack("<h", u)[0]))
    for u in decode_field(payload, _ADV_TYPE_UUID32_COMPLETE):
        services.append(bluetooth.UUID(struct.unpack("<d", u)[0]))
    for u in decode_field(payload, _ADV_TYPE_UUID128_COMPLETE):
        services.append(bluetooth.UUID(u))
    return services


def demo():
    payload = advertising_payload(
        name="micropython",
        services=[bluetooth.UUID(0x181A), bluetooth.UUID("6E400001-B5A3-F393-E0A9-E50E24DCCA9E")],
    )
    print(payload)
    print(decode_name(payload))
    print(decode_services(payload))


if __name__ == "__main__":
    demo()

蓝牙数据格式是json的字符串:

{"temp":25.5}
{"humi":27.5}

Untitled.png
wxiot.jpg

最近编辑记录 kekemuyu (2020-12-28 11:35:38)

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#2 2020-12-28 11:30:25

raspberryman
会员
注册时间: 2019-12-27
累计积分: 245

Re: 微信小程序通过蓝牙采集温湿度

哪里买的?

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#3 2020-12-29 09:35:54

vip888888
会员
注册时间: 2020-07-16
累计积分: 113

Re: 微信小程序通过蓝牙采集温湿度

uuid那些好像是要以公司名义申请之后才可以从微信端扫描到ble吧?自己重新写的是不是就不行?

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