Convert CBCharacteristic value to string

Question

I have app what working with BLE device. I have characteristic value, but I can't convert it to string. For example,

value = <aa640400 0000001e 0f>

How convert it to string?

score 1 · Answer 1 · edited Jun 10 '17 at 07:24

1

let dd = getCharacteristic.value!;

print(String(data: dd, encoding: String.Encoding.ascii)!);

edited Jun 10 '17 at 07:24

Bugs

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answered Jun 10 '17 at 05:15

Deepak Tagadiya

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Please add an explanation with your code. Code dumps are often downvoted and may even be removed. – Bugs Jun 10 '17 at 07:24
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let value = [UInt8](characteristic.value!) – Deepak Tagadiya Jul 19 '17 at 09:16

app4g · Answer 2 · 2020-10-09T02:30:48.747

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I was using the answer from sandy above and condensed it to

let data = (characteristic.value)!    
let nsdataStr = NSData.init(data: (characteristic.value)!)
print("Raw: \(nsdaraStr)")

All I wanted to do was to get the raw value (in hex) from the BLE peripheral (HR monitor in this case). The output of the above gives me:

// This is the Decimal HRArray:[22, 64, 90, 3] 
Raw: {length = 4, bytes = 0x16404e03}

This code below basically just removes the white space

let str = nsdataStr.description.trimmingCharacters(in:charSet).replacingOccurrences(of: " ", with: "")

making it

Raw: {length=4, bytes=0x16404e03}

which I didn't need.

edited Oct 09 '20 at 02:30

answered Oct 08 '20 at 13:45

app4g

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Please use https://stackoverflow.com/questions/39075043/how-to-convert-data-to-hex-string-in-swift instead. Else, this will be obsolete in future version (iOS13 changed the Data description: https://stackoverflow.com/questions/57839723/does-ios-13-has-new-way-of-getting-device-notification-token). – Larme Oct 09 '20 at 09:13

score -1 · Answer 3 · edited Jan 11 '19 at 07:10

Follow below code:

let data = (characteristic?.value)!

print(data) //-> It will be of type Data we need to convert Data to String

let charSet = CharacterSet(charactersIn: "<>")

let nsdataStr = NSData.init(data: (characteristic?.value)!)

let str = nsdataStr.description.trimmingCharacters(in:charSet).replacingOccurrences(of: " ", with: "")

print(str) // you will get String or Hex value (if its Hex need one more conversion)

Convert CBCharacteristic value to string

3 Answers3