描述

背景：

如果您沒有 Android 設(shè)備，但仍想構(gòu)建藍(lán)牙? 低能耗跳傘高度計(jì)，您會(huì)怎么做？當(dāng)然，使用 ESP32 在 RSL10-SENSE-DB-GEVK 和 OLED 顯示器上調(diào)整高度。

軟件：

我們將使用 Arduino IDE 編寫程序來控制 RSL10-SENSE-DB-GEVK，而不是構(gòu)建應(yīng)用程序。我從 BLE 客戶端示例開始并對(duì)其進(jìn)行了修改以滿足該項(xiàng)目的要求。

我們以一些聲明開始代碼：

#include "BLEDevice.h"
static BLEUUID ServiceUUID("e093f3b5-00a3-a9e5-9eca-40016e0edc24");
static BLEUUID WriteCharacteristicUUID("e093f3b7-00a3-a9e5-9eca-40036e0edc24");
static String ThisMAC = "60:c0:bf:28:99:7d";
static BLERemoteCharacteristic* WriteCharacteristic;
static BLEAdvertisedDevice* ThisDevice;
static boolean Connected = false;

當(dāng) ESP32 找到 BLE 設(shè)備時(shí)，我們需要回調(diào)。一旦我們通過 MAC 地址找到我們的 RSL10-SENSE-DB-GEVK，我們需要停止掃描。

class AdvertisedDeviceCB: public BLEAdvertisedDeviceCallbacks {
void onResult(BLEAdvertisedDevice advertisedDevice) {
if ((String)advertisedDevice.getAddress().toString().c_str() == ThisMAC) {
BLEDevice::getScan()->stop();
ThisDevice = new BLEAdvertisedDevice(advertisedDevice);
}
}
};

接下來，我們需要回調(diào)來捕獲 BLE 連接和斷開連接。這也將使用板載藍(lán)色 LED 進(jìn)行視覺確認(rèn)，當(dāng)建立連接時(shí)該 LED 會(huì)亮起。

class ClientCB : public BLEClientCallbacks {
void onConnect(BLEClient* ThisClient) {
Connected = true;
digitalWrite(LED_BUILTIN, HIGH);
}
void onDisconnect(BLEClient* ThisClient) {
Connected = false;
digitalWrite(LED_BUILTIN, LOW);
}
};

在這里，我們初始化我們的按鈕并開始 BLE 掃描：

void setup() {
pinMode(LED_BUILTIN, OUTPUT);
pinMode(22, INPUT_PULLUP);
pinMode(23, INPUT_PULLUP);
BLEDevice::init("");
BLEScan* ThisBLEScan = BLEDevice::getScan();
ThisBLEScan->setAdvertisedDeviceCallbacks(new AdvertisedDeviceCB());
ThisBLEScan->setInterval(1349);
ThisBLEScan->setWindow(449);
ThisBLEScan->setActiveScan(true);
ThisBLEScan->start(5, false);
}

最后，我們創(chuàng)建客戶端并等待建立連接，然后指定我們感興趣的服務(wù)和特性。根據(jù)我們按下的按鈕，我們將從顯示屏上的數(shù)字中增加或減少 50 英尺。

void loop() {
if (!Connected) {
BLEClient* ThisClient = BLEDevice::createClient();
do {
delay(1000);
ThisClient->setClientCallbacks(new ClientCB());
ThisClient->connect(ThisDevice);
} while (!Connected);
BLERemoteService* ThisRemoteService = ThisClient->getService(ServiceUUID);
WriteCharacteristic = ThisRemoteService->getCharacteristic(WriteCharacteristicUUID);
}
else {
if (digitalRead(22) == LOW) {
WriteCharacteristic->writeValue("+50", 3);
delay(200);
}
if (digitalRead(23) == LOW) {
WriteCharacteristic->writeValue("-50", 3);
delay(200);
}
}
}

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