Python bluetooth耳机

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数据小探 2024-12-24 08:26:50

文章标签 Python bluetooth耳机 vscode ide 编辑器 ico 文章分类 Python 后端开发

MicroPico是一个Visual Studio代码扩展，旨在简化和加速树莓派Pico和Pico W板的MicroPython项目的开发。该工具简化了编码过程，提供了代码高亮、自动补全、代码片段和项目管理功能，所有这些都是为Raspberry Pi Pico和Pico W微控制器上使用MicroPython的无缝开发体验量身定制的。

注意固件的版本要求

基于树莓派Pico W MicroPython固件的自动补全:RPI_PICO_W-20231005-v1.21.0.uf2来自micropython-stub项目的Uf2。
1，去 https://micropython.org/download/RPI_PICO_W/ 下载RPI_PICO_W-20231005-v1.21.0.uf2固件。
2，按住bootsel按钮将设备插入计算机，此时会出现RPI-RP2的盘符。
3，将下载好的Pico W最新Micropython固件拖曳到PI-RP2的盘符中去。
4，上述步骤完成后，RPI-RP2盘符自动消失。
5，在任意盘符设立项目文件夹。
6，VScode打开项目文件夹，按住ctrl+shift+p输入MicroPico: Configure Project。
7，界面最底端显示的快捷键和右键显示的扩展勾选项。

Pico W的蓝牙硬件规格

由于CYW43439无线芯片，Pico W具有无线功能。
每颗Pico W的核心是RP2040，这是Raspberry Pi的首要芯片。
英飞凌CYW43439支持 IEEE 802.11 b/g/n WLAN （Wi-Fi）和蓝牙 5.2。1.20版本在发布以前的固件和软件仅支持Wi-Fi。该CYW43439支持BLE和Wi-Fi和蓝牙之间共享的单个天线。板载 LED 通过英飞凌 43439 芯片的WL_GPIO0引脚进行控制。在 Pico 上，LED 连接到 GPIO 引脚 25。
此外，SWD调试引脚向电路板中心移动，为PCB天线腾出空间。您可以在RP2040和CYW43439之间找到它们，从左到右的顺序仍然是SWCLK，GND，SWDIO。

蓝牙经典和低功耗蓝牙（BLE）

Pico W 可与蓝牙经典和低功耗蓝牙配合使用。经典蓝牙和低功耗蓝牙（BLE）是设备在蓝牙规范内进行通信的两种不同方式。
蓝牙经典，也称为蓝牙基本速率/增强数据速率（BR/EDR），是蓝牙的原始版本。它专为高速数据传输、音频流和设备配对而设计。蓝牙经典通常用于无线音频扬声器、键盘、鼠标和设备之间的文件传输等应用。
低功耗蓝牙（BLE），也称为智能蓝牙，是蓝牙的一种节能变体。BLE 是作为蓝牙 4.0 规范的一部分引入的，针对需要长电池寿命的低功耗设备进行了优化，例如健身追踪器、智能手表、家庭自动化设备和无线传感器。
Pico W既可以用作中央设备，也可以用作外围设备。

MicroPico编程：

新建 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
    if appearance:
        _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()

新建main.py

import bluetooth
import random
import struct
import time
import machine
import ubinascii
from ble_advertising import advertising_payload
from micropython import const
from machine import Pin

_IRQ_CENTRAL_CONNECT = const(1)
_IRQ_CENTRAL_DISCONNECT = const(2)
_IRQ_GATTS_INDICATE_DONE = const(20)

_FLAG_READ = const(0x0002)
_FLAG_NOTIFY = const(0x0010)
_FLAG_INDICATE = const(0x0020)

# org.bluetooth.service.environmental_sensing
_ENV_SENSE_UUID = bluetooth.UUID(0x181A)
# org.bluetooth.characteristic.temperature
_TEMP_CHAR = (
    bluetooth.UUID(0x2A6E),
    _FLAG_READ | _FLAG_NOTIFY | _FLAG_INDICATE,
)
_ENV_SENSE_SERVICE = (
    _ENV_SENSE_UUID,
    (_TEMP_CHAR,),
)

# org.bluetooth.characteristic.gap.appearance.xml
_ADV_APPEARANCE_GENERIC_THERMOMETER = const(768)

class BLETemperature:
    def __init__(self, ble, name=""):
        self._sensor_temp = machine.ADC(4)
        self._ble = ble
        self._ble.active(True)
        self._ble.irq(self._irq)
        ((self._handle,),) = self._ble.gatts_register_services((_ENV_SENSE_SERVICE,))
        self._connections = set()
        if len(name) == 0:
            name = 'Pico %s' % ubinascii.hexlify(self._ble.config('mac')[1],':').decode().upper()
        print('Sensor name %s' % name)
        self._payload = advertising_payload(
            name=name, services=[_ENV_SENSE_UUID]
        )
        self._advertise()

    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
            self._connections.remove(conn_handle)
            # Start advertising again to allow a new connection.
            self._advertise()
        elif event == _IRQ_GATTS_INDICATE_DONE:
            conn_handle, value_handle, status = data

    def update_temperature(self, notify=False, indicate=False):
        # Write the local value, ready for a central to read.
        temp_deg_c = self._get_temp()
        print("write temp %.2f degc" % temp_deg_c);
        self._ble.gatts_write(self._handle, struct.pack("<h", int(temp_deg_c * 100)))
        if notify or indicate:
            for conn_handle in self._connections:
                if notify:
                    # Notify connected centrals.
                    self._ble.gatts_notify(conn_handle, self._handle)
                if indicate:
                    # Indicate connected centrals.
                    self._ble.gatts_indicate(conn_handle, self._handle)

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

    # ref https:///raspberrypi/pico-micropython-examples/blob/master/adc/temperature.py
    def _get_temp(self):
        conversion_factor = 3.3 / (65535)
        reading = self._sensor_temp.read_u16() * conversion_factor
        
        # The temperature sensor measures the Vbe voltage of a biased bipolar diode, connected to the fifth ADC channel
        # Typically, Vbe = 0.706V at 27 degrees C, with a slope of -1.721mV (0.001721) per degree. 
        return 27 - (reading - 0.706) / 0.001721
        
def demo():
    ble = bluetooth.BLE()
    temp = BLETemperature(ble)
    counter = 0
    led = Pin('LED', Pin.OUT)
    while True:
        if counter % 10 == 0:
            temp.update_temperature(notify=True, indicate=False)
        led.toggle()
        time.sleep_ms(1000)
        counter += 1

if __name__ == "__main__":
    demo()