最近剛出爐的7697，具有BLE功能，SimplePeripheral範例中使用BLE點亮LED，在範例目錄…\Arduino15\packages\LinkIt\hardware\linkit_rtos\0.7.11\libraries\LBLE\examples\SimplePeripheral之下有個aia檔，它用了實驗性的Bluetooth LE extension，匯入AppInventor後的畫面如下：
SimplePeripheral只用到INT類型的characteristic來控制LED，寫入1時點亮，寫入0時熄滅，在Android系統可以使用BLE Scanner或BLE UUID Explorer等App軟體來測試。其實閱讀…\Arduino15\packages\LinkIt\hardware\linkit_rtos\0.7.11\libraries\LBLE\src之程式碼可以發現，7697還有支援字串類型的characteristic，不過因為BLE的封包很短，扣除掉一些header後，在android系統每個封包最多只能傳送20 bytes。如果想用字串來傳遞WiFi AP的ssid與password，除非自行切割長字串，不然也只能使用20 bytes的ssid與密碼。下面這個程式加入了字串類型的characteristic，當使用App對characteristic進行寫入之後，7697的LBLEPeriphral.cpp會自動保存其寫入的資料，之後可用Characteristic.isWritten()判斷而將寫入的資料取出。使用BLE UUID Explorer的操作畫面，掃描裝置結果如下圖：
點選裝置後，點開Unknown service後可看到3個characteristic，畫面如下圖：
第一個Unknown characteristic是INT類型，點選進入讀寫畫面，寫入1後，7697上的LED就會點亮，這跟用AppInventor程式的效果相同，畫面如下圖：
第2個或第3個Unknown characteristic是String類型，寫入字串後再按Read讀回，證明7697的確有將資料保存起來的，畫面如下圖：
此時在Arduino終端機上可以見到輸入的字串，畫面如下圖：
程式碼如下：
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#include <LBLE.h> #include <LBLEPeriphral.h>
// Define a simple GATT service with only 1 characteristic LBLEService nodeService("19B10010-E8F2-537E-4F6C-D104768A1214"); LBLECharacteristicInt switchCharacteristic("19B10011-E8F2-537E-4F6C-D104768A1214", LBLE_READ | LBLE_WRITE); LBLECharacteristicString ssidCharacteristic("19B10012-E8F2-537E-4F6C-D104768A1214", LBLE_READ | LBLE_WRITE); LBLECharacteristicString passCharacteristic("19B10013-E8F2-537E-4F6C-D104768A1214", LBLE_READ | LBLE_WRITE); String ssid="ssid"; String pass="pass";
void setup() {
// Initialize LED pin pinMode(LED_BUILTIN, OUTPUT); digitalWrite(LED_BUILTIN, LOW);
//Initialize serial and wait for port to open: Serial.begin(9600); Serial.println("node begin");
// Initialize BLE subsystem LBLE.begin(); while (!LBLE.ready()) { delay(100); Serial.print("."); } Serial.println("BLE ready");
Serial.print("Device Address = ["); Serial.print(LBLE.getDeviceAddress()); Serial.println("]");
// configure our advertisement data. // In this case, we simply create an advertisement that represents an // connectable device with a device name LBLEAdvertisementData advertisement; advertisement.configAsConnectableDevice("BLE LED");
// Configure our device's Generic Access Profile's device name // Ususally this is the same as the name in the advertisement data. LBLEPeripheral.setName("BLE LED");
// Add characteristics into ledService nodeService.addAttribute(switchCharacteristic); nodeService.addAttribute(ssidCharacteristic); nodeService.addAttribute(passCharacteristic);
// Add service to GATT server (peripheral) LBLEPeripheral.addService(nodeService);
// start the GATT server - it is now // available to connect LBLEPeripheral.begin();
// start advertisment LBLEPeripheral.advertise(advertisement); }
void loop() { delay(100); if (switchCharacteristic.isWritten()) { const char value = switchCharacteristic.getValue(); switch (value) { case 1: digitalWrite(LED_BUILTIN, HIGH); break; case 0: digitalWrite(LED_BUILTIN, LOW); break; default: Serial.println("Unknown value written"); break; } } if (ssidCharacteristic.isWritten()) { ssid = ssidCharacteristic.getValue(); Serial.print("ssid="); Serial.println(ssid); } if (passCharacteristic.isWritten()) { pass = ssidCharacteristic.getValue(); Serial.print("pass="); Serial.println(pass); } } |
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