【得捷电子Follow me第3期】任务汇总|综合实践：无线扩展温湿度计第二屏！！！

alanlan86 · 发表于2023-12-23 20:28

【得捷电子Follow me第3期】任务汇总|综合实践：无线扩展温湿度计第二屏！！！ [复制链接]

<i class="pstatus"> 本帖最后由 alanlan86 于 2023-12-23 20:34 编辑 </i>

# 第一部分
<div id="player_72a9c5baeae54b3a63450807a11a93420" class="localvideo-box"></div><div class="localvideo-title">温湿度采集2</div><br/>
演示采用ESP32-C3 XIAO采集小米温湿度计（小米生态链企业青萍的Goose）！

# 第二部分
- 任务汇总：
- [【得捷电子Follow me第3期】任务1：使用MicroPython系统|开箱帖](https://bbs.eeworld.com.cn/thread-1263490-1-1.html "【得捷电子Follow me第3期】任务1：使用MicroPython系统|开箱帖")

- [【得捷电子Follow me第3期】任务2：驱动扩展板上的OLED屏幕|字符&中文](https://bbs.eeworld.com.cn/thread-1263808-1-1.html " 【得捷电子Follow me第3期】任务2：驱动扩展板上的OLED屏幕|字符&中文")

- [【得捷电子FollowMe第3期】任务3：控制蜂鸣器播放音乐|刷动画](https://bbs.eeworld.com.cn/thread-1263806-1-1.html "【得捷电子FollowMe第3期】任务3：控制蜂鸣器播放音乐|刷动画")

- [【得捷电子Follow me第3期】任务4：连接WiFi网络|同步网络时间](【得捷电子FollowMe第3期】任务3：控制蜂鸣器播放音乐|刷动画 "【得捷电子Follow me第3期】任务4：连接WiFi网络|同步网络时间")

- [ 【得捷电子Follow me第3期】任务5：使用外部传感器|电阻测温度](https://bbs.eeworld.com.cn/thread-1263816-1-1.html " 【得捷电子Follow me第3期】任务5：使用外部传感器|电阻测温度")

- [【得捷电子Follow m3第3期】任务6：综合实践|WiFi信号追踪](https://bbs.eeworld.com.cn/thread-1263822-1-1.html "【得捷电子Follow m3第3期】任务6：综合实践|WiFi信号追踪")

- [ 【得捷电子Follow m3第3期】任务6：综合实践|圆屏点亮时钟界面](https://bbs.eeworld.com.cn/thread-1265632-1-1.html " 【得捷电子Follow m3第3期】任务6：综合实践|圆屏点亮时钟界面")

# 第三部分
## 综合实践
- 感谢EEWrorld和得捷电子提供的机会，Follow Me 3 有幸获得参加机会！所以除了继续体验ESP32+Micropython之外，也开始上手试玩一下Arduino（PlaftormIO）。

### 简介
- 设计动机：最近寒潮来袭，广东也是瞬间入冬！看看家里的温湿度计，瞬间想到，如果在客厅壁挂了温湿度计，想在卧室看看温度，还得跑出去，瞬间发挥“码农”的动力————手搓一个温湿度显示第二屏！！！
- 后话：如果把蓝牙测温计，丢小孩的被窝里面，如果晚上踢被子，就可以在另外的卧室进行连线“闹醒”！ :Onion-5:瞬间很理工男了~~~~

### 硬件
#### 核心硬件：
- 小巧强大的ESP32-C3 XIAO
![](https://files.seeedstudio.com/wiki/XIAO_WiFi/board-pic.png)

#### 扩展板+OLED显示：
- （泪崩，扩展板上OLED烧坏了！只能通过I2C扩展了Follow me 1期的OLED显示板）
![](https://files.seeedstudio.com/wiki/Seeeduino-XIAO-Expansion-Board/Update_pic/zheng1.jpg)
#### 青萍温湿度计
![](https://img2.baidu.com/it/u=1033386465,3578526124&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=739)

### 软件
#### A、开发环境
采用VSCode+PlatformIO，将ESP32-C3的开发环境搭建好。
#### B、代码库
采用了NimBLE-Arduino，OLED显示的代码库u8g2
```c
[env:seeed_xiao_esp32c3]
platform = espressif32
board = seeed_xiao_esp32c3
framework = arduino
lib_deps = 
	h2zero/NimBLE-Arduino@^1.4.1
	olikraus/U8g2@^2.35.8
```
#### C、蓝牙代码
- 参考example code里面的BLE Client例程进行修改。作为client端需要将蓝牙扫描打开，同时，由于温湿度计连接无需做配对，所以需要将配对代码部分接口调用注释掉。
#### ①初始化客户端

```cpp
void setup (){
    Serial.begin(115200);
    Serial.println("Starting NimBLE Client");

u8g2.begin();
    //u8g2.setFlipMode(1);   // set number from 1 to 3, the screen word will rotary 180

u8g2.clearBuffer();                   // clear the internal memory
    u8g2.setFont(u8g2_font_ncenB08_tr);   // choose a suitable font
    u8g2.drawStr(0,15,"Goose Sensor");    // write something to the internal memory
    u8g2.drawStr(0,30,"Start...");
    u8g2.drawStr(0,40,"BLE Scan..");
    u8g2.sendBuffer();                    // transfer internal memory to the display

/** Initialize NimBLE, no device name spcified as we are not advertising */
    NimBLEDevice::init("");

/** Set the IO capabilities of the device, each option will trigger a different pairing method.
     *  BLE_HS_IO_KEYBOARD_ONLY    - Passkey pairing
     *  BLE_HS_IO_DISPLAY_YESNO   - Numeric comparison pairing
     *  BLE_HS_IO_NO_INPUT_OUTPUT - DEFAULT setting - just works pairing
     */
    //NimBLEDevice::setSecurityIOCap(BLE_HS_IO_KEYBOARD_ONLY); // use passkey
    //NimBLEDevice::setSecurityIOCap(BLE_HS_IO_DISPLAY_YESNO); //use numeric comparison

/** 2 different ways to set security - both calls achieve the same result.
     *  no bonding, no man in the middle protection, secure connections.
     *
     *  These are the default values, only shown here for demonstration.
     */
    //NimBLEDevice::setSecurityAuth(false, false, true);
    //NimBLEDevice::setSecurityAuth(/*BLE_SM_PAIR_AUTHREQ_BOND | BLE_SM_PAIR_AUTHREQ_MITM |*/ BLE_SM_PAIR_AUTHREQ_SC);

/** Optional: set the transmit power, default is 3db */
#ifdef ESP_PLATFORM
    NimBLEDevice::setPower(ESP_PWR_LVL_P9); /** +9db */
#else
    NimBLEDevice::setPower(9); /** +9db */
#endif

/** Optional: set any devices you don't want to get advertisments from */
    // NimBLEDevice::addIgnored(NimBLEAddress ("aa:bb:cc:dd:ee:ff"));

/** create new scan */
    NimBLEScan* pScan = NimBLEDevice::getScan();

/** create a callback that gets called when advertisers are found */
    pScan->setAdvertisedDeviceCallbacks(new AdvertisedDeviceCallbacks());

/** Set scan interval (how often) and window (how long) in milliseconds */
    pScan->setInterval(500);
    pScan->setWindow(450);

/** Active scan will gather scan response data from advertisers
     *  but will use more energy from both devices
     */
    pScan->setActiveScan(true);
    /** Start scanning for advertisers for the scan time specified (in seconds) 0 = forever
     *  Optional callback for when scanning stops.
     */
    pScan->start(scanTime, scanEndedCB);
}
```
#### ②扫描及连接

- 考虑到扫描->连接的时间效率，将scan的window和interval做一下调整！

- 通过扫描获得周边广播设备（server端）的广播内容。此处，调整一下例程原有通过service uuid进行匹配的规则，采用DeviceName=Goose进行匹配，然后决定发起连接。

```cpp
/** Define a class to handle the callbacks when advertisments are received */
class AdvertisedDeviceCallbacks: public NimBLEAdvertisedDeviceCallbacks {

void onResult(NimBLEAdvertisedDevice* advertisedDevice) {
        Serial.print("Advertised Device found: ");
        Serial.println(advertisedDevice->toString().c_str());
        //if(advertisedDevice->isAdvertisingService(NimBLEUUID(SERVICE_UUID)))
        if (advertisedDevice->getName() == "Goose")
        {
            Serial.println("Found Our Service");
            /** stop scan before connecting */
            NimBLEDevice::getScan()->stop();
            /** Save the device reference in a global for the client to use*/
            advDevice = advertisedDevice;
            /** Ready to connect now */
            doConnect = true;
        }
    };
};
```
#### ③匹配Server端
- 通过扫描&连接后，对目标设备发起连接，则需要继续匹配Server端的service uuid和characteristic的uuid，主要代码在connectToServer()函数中。

```cpp
void loop (){
    /** Loop here until we find a device we want to connect to */
    while(!doConnect){
        delay(1);
    }

doConnect = false;

/** Found a device we want to connect to, do it now */
    if(connectToServer()) {
        Serial.println("Success! we should now be getting notifications, scanning for more!");
    } else {
        Serial.println("Failed to connect, starting scan");
    }

//NimBLEDevice::getScan()->start(scanTime,scanEndedCB);
}
```

- connectToServer()函数主要匹配服务及特征值部分代码。调整服务UUID，匹配特征值UUID的主要内容，是实现和温湿度计匹配的关键代码。。

```cpp
/** Handles the provisioning of clients and connects / interfaces with the server */
bool connectToServer() {
    NimBLEClient* pClient = nullptr;

/** Check if we have a client we should reuse first **/
    if(NimBLEDevice::getClientListSize()) {
        /** Special case when we already know this device, we send false as the
         *  second argument in connect() to prevent refreshing the service database.
         *  This saves considerable time and power.
         */
        pClient = NimBLEDevice::getClientByPeerAddress(advDevice->getAddress());
        if(pClient){
            if(!pClient->connect(advDevice, false)) {
                Serial.println("Reconnect failed");
                return false;
            }
            Serial.println("Reconnected client");
        }
        /** We don't already have a client that knows this device,
         *  we will check for a client that is disconnected that we can use.
         */
        else {
            pClient = NimBLEDevice::getDisconnectedClient();
        }
    }

/** No client to reuse? Create a new one. */
    if(!pClient) {
        if(NimBLEDevice::getClientListSize() >= NIMBLE_MAX_CONNECTIONS) {
            Serial.println("Max clients reached - no more connections available");
            return false;
        }

pClient = NimBLEDevice::createClient();

Serial.println("New client created");

pClient->setClientCallbacks(&clientCB, false);
        /** Set initial connection parameters: These settings are 15ms interval, 0 latency, 120ms timout.
         *  These settings are safe for 3 clients to connect reliably, can go faster if you have less
         *  connections. Timeout should be a multiple of the interval, minimum is 100ms.
         *  Min interval: 12 * 1.25ms = 15, Max interval: 12 * 1.25ms = 15, 0 latency, 51 * 10ms = 510ms timeout
         */
        pClient->setConnectionParams(12,12,0,51);
        /** Set how long we are willing to wait for the connection to complete (seconds), default is 30. */
        pClient->setConnectTimeout(5);

if (!pClient->connect(advDevice)) {
            /** Created a client but failed to connect, don't need to keep it as it has no data */
            NimBLEDevice::deleteClient(pClient);
            Serial.println("Failed to connect, deleted client");
            return false;
        }
    }

if(!pClient->isConnected()) {
        if (!pClient->connect(advDevice)) {
            Serial.println("Failed to connect");
            return false;
        }
    }

Serial.print("Connected to: ");
    Serial.println(pClient->getPeerAddress().toString().c_str());
    Serial.print("RSSI: ");
    Serial.println(pClient->getRssi());

/** Now we can read/write/subscribe the charateristics of the services we are interested in */
    NimBLERemoteService* pSvc = nullptr;
    NimBLERemoteCharacteristic* pChr = nullptr;
    NimBLERemoteDescriptor* pDsc = nullptr;

pSvc = pClient->getService(SERVICE_UUID);
    if(pSvc) {     /** make sure it's not null */
        pChr = pSvc->getCharacteristic(CHAR_UUID);

if(pChr) {     /** make sure it's not null */
            if(pChr->canRead()) {
                Serial.print(pChr->getUUID().toString().c_str());
                Serial.print(" Value: ");
                Serial.println(pChr->readValue().c_str());
            }

if(pChr->canWrite()) {
                if(pChr->writeValue("Tasty")) {
                    Serial.print("Wrote new value to: ");
                    Serial.println(pChr->getUUID().toString().c_str());
                }
                else {
                    /** Disconnect if write failed */
                    pClient->disconnect();
                    return false;
                }

if(pChr->canRead()) {
                    Serial.print("The value of: ");
                    Serial.print(pChr->getUUID().toString().c_str());
                    Serial.print(" is now: ");
                    Serial.println(pChr->readValue().c_str());
                }
            }

/** registerForNotify() has been deprecated and replaced with subscribe() / unsubscribe().
             *  Subscribe parameter defaults are: notifications=true, notifyCallback=nullptr, response=false.
             *  Unsubscribe parameter defaults are: response=false.
             */
            if(pChr->canNotify()) {
                //if(!pChr->registerForNotify(notifyCB)) {
                if(!pChr->subscribe(true, notifyCB)) {
                    /** Disconnect if subscribe failed */
                    pClient->disconnect();
                    return false;
                }
            }
            else if(pChr->canIndicate()) {
                /** Send false as first argument to subscribe to indications instead of notifications */
                //if(!pChr->registerForNotify(notifyCB, false)) {
                if(!pChr->subscribe(false, notifyCB)) {
                    /** Disconnect if subscribe failed */
                    pClient->disconnect();
                    return false;
                }
            }
        }

} else {
        Serial.println("Goose Sensor service not found.");
    }

Serial.println("Done with this device!");
    return true;
}
```

##### ④接收温湿度
- 接收温湿度计通知Notify的温湿度数值，并做OLED显示。

```cpp
/** Notification / Indication receiving handler callback */
void notifyCB(NimBLERemoteCharacteristic* pRemoteCharacteristic, uint8_t* pData, size_t length, bool isNotify){
    uint16_t humidity, temperature;
    char data[64];
    std::string str = (isNotify == true) ? "Notification" : "Indication";
    str += " from ";

temperature = (pData[3] << 8)|(pData[2] << 0);
	humidity    = (pData[5] << 8)|(pData[4] << 0);
	
	//Serial.printf("rx data:0x%x,0x%x,", pData[0], pData[1]);
	snprintf(data, sizeof(data), "humidity=%d,temperature=%d\r\n", humidity&(~(1 << 15)), temperature);

/** NimBLEAddress and NimBLEUUID have std::string operators */
    str += std::string(pRemoteCharacteristic->getRemoteService()->getClient()->getPeerAddress());
    str += ": Service = " + std::string(pRemoteCharacteristic->getRemoteService()->getUUID());
    str += ", Characteristic = " + std::string(pRemoteCharacteristic->getUUID());
    //str += ", Value = " + std::string((char*)pData, length);
    str += data;
    Serial.println(str.c_str());

//display on OLED screen
    u8g2.clearBuffer();                   // clear the internal memory
    u8g2.setFont(u8g2_font_ncenB08_tr);   // choose a suitable font
    u8g2.drawStr(0,15,"Goose Sensor");    // write something to the internal memory
    u8g2.drawStr(0,30,"Get Data...");
    snprintf(data, sizeof(data), "temperature:%.01f", float(temperature/10.0));
    u8g2.drawStr(0,40,data);
    snprintf(data, sizeof(data), "himidity:%.01f", float(humidity/10.0));
    u8g2.drawStr(0,50,data);
    u8g2.sendBuffer();                    // transfer internal memory to the display
}

```

### 调试
- 代码烧录后，可以由ESP32-C3 对温湿度计进行连接，且可以获取到温湿度计，通过串口打印。

<ignore_js_op>

<a href="javascript:;" onclick="showWindow(this.id, this.getAttribute('url'), 'get', 0);" id="savephoto_767010" url="home.php?mod=spacecp&ac=album&op=saveforumphoto&aid=767010&handlekey=savephoto_767010">保存到相册</a>

</p>

</div>
<div class="tip_horn"></div>
</div>

</ignore_js_op>

- 温湿度获取后OLED显示。

<ignore_js_op>

<div class="tip tip_4 aimg_tip" id="aimg_767011_menu" style="position: absolute; display: none" disautofocus="true">
<div class="xs0">
<p><strong>温湿度显示.jpg</strong> <em class="xg1">(482.34 KB, 下载次数: 0)</em></p>
<p>
<a href="javascript:;" class="loginf" >下载附件</a>

<a href="javascript:;" onclick="showWindow(this.id, this.getAttribute('url'), 'get', 0);" id="savephoto_767011" url="home.php?mod=spacecp&ac=album&op=saveforumphoto&aid=767011&handlekey=savephoto_767011">保存到相册</a>

</p>

</div>
<div class="tip_horn"></div>
</div>

</ignore_js_op>

### 源码

<ignore_js_op>

<a href="javascript:;" class="loginf">BLEDemo.zip</a>

<em class="xg1">(11.95 MB, 下载次数: 0)</em>
</span>
<div class="tip tip_4" id="attach_767012_menu" style="position: absolute; display: none" disautofocus="true">
<div class="tip_c xs0">
<div class="y">2023-12-23 20:24 上传</div>
点击文件名下载附件
源码
</div>
<div class="tip_horn"></div>
</div>

</ignore_js_op>

### 总结
- 动手永远是乐趣的起点！因此follow me第4期，也开始了！希望能够继续有机会参加活动，可以接触上手更多好玩有趣的小玩儿！~~~感谢EEWorld提供的平台，得捷电子的赞助支持！
 :Onion-8:  :Onion-8: :Onion-19:  :Onion-19:

【得捷电子Follow me第3期】任务汇总|综合实践：无线扩展温湿度计第二屏！！！ [复制链接]

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