iOS swift 将 BLE 数据传递给单独的 class ZC1C425268E68385D1AB5074C17A94

Question

I am sure this has been answered somewhere, but I am not sure what to search for. I am in the early stages of a simple BLE iOS app and trying to work out how to transfer the incoming BLE data to a separate function. The data incoming from BLE is converting into an array, but I believe it's not possible to send this to a different function. I try to send it as a string, but then it seems impossible to break the string into an array.

Could someone advice what is the most efficient way to transfer the incoming BLE data to a separate functions?

This is the code in the func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) :

// Decode the incoming BLE into bytes
let data2 = characteristic.value
let count = (data2?.count)! / MemoryLayout<UInt8>.size
var array = [UInt8](repeating: 0, count: count)
data?.copyBytes(to: &array, count:count * MemoryLayout<UInt8>.size)
// Transfer the incoming BLE data to a sepurate class to decode
var stringFromData = String(data: characteristic.value!, encoding: String.Encoding.ascii)
// How to transfer the incoming BLE data to a sepurate class?
BLE_Element_One_DataExtract_class.DummyFunc(_IncomingElementOneData: stringFromData!, _IncomingUUID: characteristic.uuid)

print("BLE incoming data in an array = ")
let x=0
for x in array
{
    print("\(array) BLE data \n")
    
}

// Separate class and function to decode the BLE data and store in the MVVM
// This code does not work, as it does not treat the incoming data as a string 

class BLE_Element_One_DataExtract
{
    func DummyFunc(_IncomingElementOneData:String, _IncomingUUID:CBUUID)
    {
        let data
        let data2 = _IncomingElementOneData
        let count = (data2?.count)! / MemoryLayout<UInt8>.size
        var array = [UInt8](repeating: 0, count: count)
        data?.copyBytes(to: &array, count:count * MemoryLayout<UInt8>.size)
        
        print("data is -> : ", terminator : "")
        
        if(_IncomingUUID.isEqual(CBUUIDs.ECHO_DISPLAY_ELEMENT_STATUS_ONE_UUID_CHAR))
        {
            print ("Found ECHO_DISPLAY_ELEMENT_STATUS_ONE_UUID_CHAR inner func")
            // BLE_Element_One_DataExtract(?? send data string ??)
        }
    }
}

Answer 1

I suppose you want to convert characteristic.value (it has type Data? ) to a variable of type String .

You mentioned you want String , but in code you also work with [UInt8] , so I'm not sure if I understand what you want to do.

You've already implemented listening for the updates with func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) , and reading the incoming data from characteristic.value , so it remains to convert the data to the wanted type.

Conversion example (if characteristic.value is nil, or conversion error, result will be an empty string):

let data = characteristic.value ?? Data()
let stringValue = String(data: data, encoding: .utf8) ?? ""
// pass stringValue where you need it

Also you can pass data to the destination function "as is" using type Data? , so it will be the job of destination function to decide what to do with it:

func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) {
    DataDestinationClass.doSomething(data: characteristic.value, uuid: characteristic.uuid)
}

class DataDestinationClass {
    static func doSomething(data: Data?, uuid: CBUUID) {
        let stringValue = String(data: data ?? Data(), encoding: .utf8) ?? ""
        print("MYLOG: stringValue = '\(stringValue)'")
    }
}

Here is an example of putting the received characteristic.value to the Text Field: https://github.com/alexanderlavrushko/BLEProof-collection/blob/5cbb089dbfed42cfb8aad0db236a376ff1cce620/iOS/BLEProofCentral/BLEProofCentral/BLECentralViewController.swift#L295

Answer 2

"The data incoming from BLE is converting into an array, but I believe it's not possible to send this to a different function."

No, it's trivial to pass your data array to another function:

// Your code
var array = [UInt8](repeating: 0, count: count)
data?.copyBytes(to: &array, count:count * MemoryLayout<UInt8>.size)

// At this point you can simply pass your array to another
// function (which could be in a different class)
otherClass.processData(data: array)

The class / function receiving the data could simply look like this:

class OtherClass {
    func processData(data: [UInt8]) {
        // Do something with your data
    }
}