为了解决这个问题,我们需要检查HM10是否正确设置了读属性。以下是一个示例代码:
BLEDevice central;
BLEAddress addr;
BLEClient client;
BLEService service;
BLECharacteristic characteristic;
// 连接到 BLE 设备
central.connect(addr);
// 获取 BLE 服务
client = central.getService(serviceUUID);
// 获取 BLE 特征
characteristic = client.getCharacteristic(charUUID);
if (characteristic.canRead()) {
// 从 BLE 特征中读取数据
uint8_t value[20];
characteristic.readValue(value, 20);
} else {
// 特征不可读,输出错误信息
Serial.println("Error: characteristic cannot be read.");
}
在这个示例代码中,我们首先连接到BLE设备并获取服务。接下来,我们从服务中获取特征,检查该特征是否具有读取属性,如果是,则可以使用 readValue()
方法读取数据。如果特征不具备读取属性,则会输出一个错误信息。