swift - didDiscoverCharacteristicsFor 没有返回 HM-10 BLE 的任何特征

Question

我成功地能够使用 didDiscoverServices 发现服务，从那里我调用以下函数来发现特征:

peripheral.discoverCharacteristics(nil, for: service as CBService)

func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {

    if error != nil {
        print("[ERROR] Error discovering characteristics. \(error!.localizedDescription)")
        return
    }

    print("Found \(service.characteristics!.count) characteristics!: \(service.characteristics)")        
}

这会打印:“找到 0 个特征!:可选([])”

我没有从 BLE 设备获得任何特征。感谢您的帮助。

Answer 1

一般在连接之后，下一步就是发现服务。现在每项服务都有自己的特点。在你上面打电话

peripheral.discoverCharacteristics(nil, for: service as CBService)

服务作为 CBService 可能有也可能没有任何特征。我建议你做一件事，检查你的 BLE 设备拥有的所有服务，然后发现所有服务的特征。

func peripheral(peripheral: CBPeripheral, didDiscoverServices error: NSError?) {
    guard let serviceError = error else {
        if let peripheralServices = peripheral.services {
            for service in peripheralServices {
                peripheral.discoverCharacteristics(nil, forService: service)
            }
        }
        return
    }

    print("Error in discovering Services. Error : \(serviceError.localizedDescription)")
}

希望对你有帮助。快乐编码:)