I have connected to two iPhones and found the services and characteristics in it. I am facing problems in sending write requests from central and receiving response from peripheral. I have written the code below to write data in central and received data in Peripheral. But the function didReceiveWriteRequests didn't execute. I don't know Why didn't work.
In central view write, the data code:
func writeValue(data:NSData){
if let discoveredPeripheral = discoveredPeripheral{
if let deviceCharacteristics = deviceCharacteristics{
discoveredPeripheral.writeValue(data, forCharacteristic: deviceCharacteristics, type: CBCharacteristicWriteType.WithResponse)
}
}
}
and in peripheral view, the receive code:
func peripheralManager(peripheral: CBPeripheralManager!, didReceiveWriteRequests requests: [AnyObject]!) {
println("didReceiveWriteRequests")
println("\(requests.count)")
}
Related
I'm developing and app for iOS which needs to connect to a Bluetooth Device. I've been able to find and connect to devices near me using CoreBluetooth and GATT profile. The writing and reading of characteristics worked as well. These values will eventually be written when a slider is moved. However, now I also need to be able to stream audio to the Bluetooth Device.
When I looked around for streaming audio over bluetooth I noticed this could be done with AVFoundation by allowing output over bluetooth. However, then the device has to use A2DP profile. But this causes the app to be unable to read/write characteristics?
I got this piece of code to read, notify and write to specific characteristics.
func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService,
error: Error?) {
guard let characteristics = service.characteristics else { return }
for characteristic in characteristics {
print(characteristic)
if characteristic.properties.contains(.read) {
print("\(characteristic.uuid): properties contains .read")
if characteristic.uuid == batteryLevelCharacteristicCBUUID { peripheral.readValue(for: characteristic) }
}
if characteristic.properties.contains(.notify) {
print("\(characteristic.uuid): properties contains .notify")
if characteristic.uuid == batteryLevelCharacteristicCBUUID {
peripheral.setNotifyValue(true, for: characteristic)
}
}
if characteristic.properties.contains(.write) {
print("\(characteristic.uuid): properties contains .write")
if characteristic.uuid == writeTestCharacteristicCBUUID {
print("Writing characteristic found! Trying to write now.")
let string = "Hello World!"
let data = string.data(using: .utf8)!
peripheral.writeValue(data, for: characteristic, type: CBCharacteristicWriteType.withResponse)
}
}
}
}
This question seems similar but it is mentioned that it's not possible. Is possible send hexadecimal data to A2DP Bluetooth Device in swift?
However, I was thinking. If you look at a headset for example when you press buttons there has to be some data transfer. Can this somehow be used for what I want to do? But I can't seem to find any information about these signals or how to use those in my code.
So what I want is to be able to stream the audio and also send small values like percentages.
If you know any information that might help me please let me know. Thanks in advance!
I am writing an app that needs to write a byte value to a CBPeripheral using iOS CoreBluetooth. I am able to read values, and the write is successful and triggers the didWriteValueFor delegate like it should. Basically, it does work, BUT, it takes a long time (about 3 seconds and reports of over 10). When I test the write process in another app (nRF Connect), the write is almost instantaneous. Here's the code I am using to write to the Characteristic:
func setConfigurationValue(_ i:UInt8){
guard peripheral != nil, configurationStateCharacteristic != nil else { return }
var vint:UInt8 = i
let intData = Data(bytes: &vint, count: MemoryLayout<UInt8>.size)
isWriting = true
peripheral?.writeValue(intData, for: configurationStateCharacteristic!, type: CBCharacteristicWriteType.withResponse)
// Notify any views that they should show a progress overlay
NotificationName.showProgressOverlay.post(userInfo: ["message":"Device configuring".localized], object: self)
}
Note, that peripheral is a stored reference to the CBPeripheral object, and configurationStateCharacteristic is a reference to the CBCharacteristic I am writing to. This code does work, but what is causing the peripheral BLE device to take so long in writing the data and sending a response?
Any ideas?
I'm making BLE trnasport between tizen and ios using ble. I can send and receive data but I want to add some logic.
IOS function, didreceivewriterequests() callback is called when ios receive data and I want to store received data to a list with uuid.
Tizen already have this logic. But I don't know how to get uuid to identify what uuid is including data. I want to get the data in other funciton with a list by uuid.
How to get uuid in didreceivewriterequests() callback?
Thank you.
As I see, CBATTRequest.characteristic.UUID is deprecated.
characteristic.uuid is not deprecated. You need to access it from each request in the requests array. From there you can retreive the UUID of the characteristic.
func peripheralManager(_ peripheral: CBPeripheralManager, didReceiveWrite requests: [CBATTRequest]) {
for request in requests {
let id = request.characteristic.uuid
print("ID is \(id.uuidString)")
}
}
Swift 3
func peripheralManager(_ peripheral: CBPeripheralManager, didReceiveWrite requests: [CBATTRequest]) {
for writeRequest in requests {
print(characteristic.uuid.uuidString)
}
}
If i want to send data to a bluetooth module, which is connected to the Arduino, what code lines are specifically the ones I need to take notice of.
I want to send something like, the number '75' to the bluetooth module and the Arduino will read it
thanks
Bluetooth LE is very long and cumbersome with many delegates in between. The minimum path to write your data is:
Make sure you have bluetooth permission: CBCentralManagerDelegate.centralManagerDidUpdateStateand if so start scanning with scanForPeripherals
CBCentralManagerDelegate.didDiscover If this is the peripheral you want then set yourself as its delegate
CBPeripheralDelegate.peripheral:didDiscoverServices: If this is the service you want then stop scanning and discoverCharacteristics:for: service
CBPeripheralDelegate.peripheral:didDiscoverCharacteristicsFor: service If a characteristic in the array of characteristics is the one you want then:
func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {
guard let characteristics = service.characteristics else {
return
}
for characteristic in characteristics {
if characteristic.uuid == CBUUID(string: characteristicIdentifier) {
let value: UInt8 = 75
let data = Data(bytes: [value])
peripheral.writeValue(data, for: characteristic, type: .withResponse)
}
}
}
I am working on arduino project which involves it sending/receiving data from the iPhone to to an arduino through a BLE board. I am struggling with receiving data from the arduino back to the iPhone.
I have this function:
func readPosition() -> NSString? {
if self.positionCharacteristic == nil {
return nil
}
self.peripheral?.readValue(for: self.positionCharacteristic!)
if ((self.positionCharacteristic?.value) != nil) {
return NSString(data: self.positionCharacteristic!.value!, encoding:
String.Encoding.utf8.rawValue) }
return nil
}
My problem with it is that I don't understand how to use it in a way that it will immediately read and use what was sent from the arduino. How would I code my project to accomplish this? I need to receive constant data from a sensor that is attached to the arduino
The receiving UUID if needed:
let PositionCharUUID = CBUUID(string: "A9CD2F86-8661-4EB1-B132-367A3434BC90")
It is likely (but you need to check) that your characteristic supports Notify operations. In this case you can use
self.peripheral.setNotifyValue(true, for: self.positionCharacteristic)
You will then get a call to your peripheral delegate's didUpdateValue:for: method