add CBPeripehral.GetMaximumWriteValueLength

Assets/CoreBluetooth/Samples/12_Debug/SampleDebug_Central.cs

@@ -42,6 +42,7 @@ public void DidUpdateState(CBCentralManager central)
         public void DidConnectPeripheral(CBCentralManager central, CBPeripheral peripheral)
         {
             Debug.Log($"[DidConnectPeripheral] peripheral: {peripheral}");
+            Debug.Log($"[DidConnectPeripheral] mtu: {peripheral.GetMaximumWriteValueLength(CBCharacteristicWriteType.WithResponse)}");
             peripheral.DiscoverServices(new string[] { _serviceUUID });
         }
 

Packages/com.teach310.core-bluetooth-for-unity/Runtime/CBPeripheral.cs

@@ -95,6 +95,14 @@ public void WriteValue(byte[] data, CBCharacteristic characteristic, CBCharacter
             _nativePeripheral.WriteValue(data, characteristic, type);
         }
 
+        /// <summary>
+        /// The maximum amount of data, in bytes, you can send to a characteristic in a single write type.
+        /// </summary>
+        public int GetMaximumWriteValueLength(CBCharacteristicWriteType type)
+        {
+            return _nativePeripheral.GetMaximumWriteValueLength(type);
+        }
+
         /// <summary>
         /// Sets notifications or indications for the value of a specified characteristic.
         /// </summary>

Packages/com.teach310.core-bluetooth-for-unity/Runtime/NativeMethods.cs

@@ -132,6 +132,9 @@ internal static extern int cb4u_peripheral_write_characteristic_value(
             int writeType
         );
 
+        [DllImport(DLL_NAME, CallingConvention = CallingConvention.Cdecl)]
+        internal static extern int cb4u_peripheral_maximum_write_value_length(SafeNativePeripheralHandle handle, int writeType);
+
         [DllImport(DLL_NAME, CallingConvention = CallingConvention.Cdecl)]
         internal static extern int cb4u_peripheral_set_notify_value(
             SafeNativePeripheralHandle handle,

Packages/com.teach310.core-bluetooth-for-unity/Runtime/NativePeripheralProxy.cs

@@ -106,6 +106,11 @@ internal void WriteValue(byte[] data, CBCharacteristic characteristic, CBCharact
             ExceptionUtils.ThrowIfCharacteristicNotFound(result, characteristic.UUID);
         }
 
+        internal int GetMaximumWriteValueLength(CBCharacteristicWriteType writeType)
+        {
+            return NativeMethods.cb4u_peripheral_maximum_write_value_length(_handle, (int)writeType);
+        }
+
         internal void SetNotifyValue(bool enabled, CBCharacteristic characteristic)
         {
             int result = NativeMethods.cb4u_peripheral_set_notify_value(

Plugins/CoreBluetoothForUnity/Sources/CoreBluetoothForUnity/CB4UPeripheral.swift

@@ -80,6 +80,10 @@ public class CB4UPeripheral : NSObject {
         }
     }
 
+    public func maximumWriteValueLength(_ writeType: CBCharacteristicWriteType) -> Int32 {
+        return Int32(peripheral.maximumWriteValueLength(for: writeType))
+    }
+
     public func setNotifyValue(_ serviceUUID: CBUUID, _ characteristicUUID: CBUUID, _ enabled: Bool) -> Int32 {
         return actionForCharacteristic(serviceUUID, characteristicUUID) { (service, characteristic) -> Void in
             peripheral.setNotifyValue(enabled, for: characteristic)
@@ -97,7 +101,7 @@ extension CB4UPeripheral : CBPeripheralDelegate {
 
     public func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: Error?) {
         let commaSeparatedServiceIds = peripheral.services?.map { $0.uuid.uuidString }.joined(separator: ",") ?? ""
-
+        
         commaSeparatedServiceIds.withCString { (commaSeparatedServiceIdsCString) in
             didDiscoverServicesHandler?(selfPointer(), commaSeparatedServiceIdsCString, errorToCode(error))
         }
@@ -106,7 +110,7 @@ extension CB4UPeripheral : CBPeripheralDelegate {
     public func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {
         let serviceId = service.uuid.uuidString
         let commaSeparatedCharacteristicIds = service.characteristics?.map { $0.uuid.uuidString }.joined(separator: ",") ?? ""
-
+        
         serviceId.withCString { (serviceIdCString) in
             commaSeparatedCharacteristicIds.withCString { (commaSeparatedCharacteristicIdsCString) in
                 didDiscoverCharacteristicsHandler?(selfPointer(), serviceIdCString, commaSeparatedCharacteristicIdsCString, errorToCode(error))

Plugins/CoreBluetoothForUnity/Sources/CoreBluetoothForUnity/CoreBluetoothForUnity.swift

@@ -229,6 +229,16 @@ public func cb4u_peripheral_write_characteristic_value(
     return instance.writeCharacteristicValue(CBUUID(string: String(cString: serviceUUID)), CBUUID(string: String(cString: characteristicUUID)), data, CBCharacteristicWriteType(rawValue: Int(writeType))!)
 }
 
+@_cdecl("cb4u_peripheral_maximum_write_value_length")
+public func cb4u_peripheral_maximum_write_value_length(
+    _ peripheralPtr: UnsafeRawPointer,
+    _ writeType: Int32
+) -> Int32 {
+    let instance = Unmanaged<CB4UPeripheral>.fromOpaque(peripheralPtr).takeUnretainedValue()
+
+    return Int32(instance.maximumWriteValueLength(CBCharacteristicWriteType(rawValue: Int(writeType))!))
+}
+
 @_cdecl("cb4u_peripheral_set_notify_value")
 public func cb4u_peripheral_set_notify_value(
     _ peripheralPtr: UnsafeRawPointer,