Jira 794 Inconsistent writeInt() result with different Peripherals, git 385

Root cause:
-  As a Central, the write() operation can produce two different
   commands to a Peripheral depending on the Characteristic.
-  One command is a simple write without aknowledgement from
   Peripheral and the other requires a complete handshake for
   each write operation.
-  Root cause of the issue was that the function,
   BLECharacteristicImp::write(), did not check the
   characteristic property to determine if the caller requires
   a response.  It just treats all calls do not require a
   response.

Feature added:
-  For write with respond from Peripheral, it is now a
   blocking call (it also satisfied Arduino's request).

Modifications:
1. libraries/CurieBLE/src/internal/BLECallbacks.cpp:
   - ble_on_write_no_rsp_complete:  CB to process Peripheral
     Response to complete a write operation.
2. libraries/CurieBLE/src/internal/BLECallbacks.h:
   - Function definition added.
3. libraries/CurieBLE/src/internal/BLECharacteristicImp.cpp:
   - In function write(), check the characteristic property to
     determine whether the call requires a response.
   - Added a flag to signal the waiting on Peripheral
     Response for a write operation.
   - Write with response is now a blocking call.
4. BLECharacteristicImp.h:
   - Prototyping.

Author: sgbihu

libraries/CurieBLE/src/internal/BLECallbacks.cpp

@@ -223,4 +223,9 @@ void ble_central_device_found(const bt_addr_le_t *addr,
                                                   ad, len);
 }
 
+void ble_on_write_no_rsp_complete(struct bt_conn *conn, uint8_t err,
+                                         const void *data)
+{
+    BLECharacteristicImp::writeResponseReceived(conn, err, data);
+}
 

libraries/CurieBLE/src/internal/BLECallbacks.h

@@ -74,5 +74,8 @@ uint8_t profile_service_read_rsp_process(bt_conn_t *conn,
                                  const void *data, 
                                  uint16_t length);
 
+void ble_on_write_no_rsp_complete(struct bt_conn *conn, uint8_t err,
+                                         const void *data);
+
 #endif
 

libraries/CurieBLE/src/internal/BLECharacteristicImp.cpp

@@ -27,6 +27,7 @@
 
 bt_uuid_16_t BLECharacteristicImp::_gatt_chrc_uuid = {BT_UUID_TYPE_16, BT_UUID_GATT_CHRC_VAL};
 bt_uuid_16_t BLECharacteristicImp::_gatt_ccc_uuid = {BT_UUID_TYPE_16, BT_UUID_GATT_CCC_VAL};
+volatile bool BLECharacteristicImp::_gattc_writing = false;
 
 BLECharacteristicImp::BLECharacteristicImp(const bt_uuid_t* uuid, 
                                            unsigned char properties,
@@ -637,13 +638,20 @@ bool BLECharacteristicImp::read()
     return _reading;
 }
 
+void BLECharacteristicImp::writeResponseReceived(struct bt_conn *conn, 
+                                                 uint8_t err,
+                                                 const void *data)
+{
+    _gattc_writing = false;
+}
+
 bool BLECharacteristicImp::write(const unsigned char value[], 
                                  uint16_t length)
 {
     int retval = 0;
     bt_conn_t* conn = NULL;
 
-    if (true == BLEUtils::isLocalBLE(_ble_device))
+    if (true == BLEUtils::isLocalBLE(_ble_device) || true == _gattc_writing)
     {
         // GATT server can't write
         return false;
@@ -655,12 +663,29 @@ bool BLECharacteristicImp::write(const unsigned char value[],
         return false;
     }
 
-    // Send read request
-    retval = bt_gatt_write_without_response(conn, 
-                                            _value_handle,
-                                            value, 
-                                            length, 
-                                            false);
+    // Send write request
+    if (_gatt_chrc.properties | BT_GATT_CHRC_WRITE_WITHOUT_RESP)
+    {
+        retval = bt_gatt_write_without_response(conn, 
+                                                _value_handle,
+                                                value, 
+                                                length, 
+                                                false);
+    }
+    else if (_gatt_chrc.properties | BT_GATT_CHRC_WRITE)
+    {
+        _gattc_writing = true;
+        retval = bt_gatt_write(conn, 
+                               _value_handle,
+                               0,
+                               value, 
+                               length, 
+                               ble_on_write_no_rsp_complete);
+        while (_gattc_writing)
+        {
+            delay(2);
+        }
+    }
     bt_conn_unref(conn);
     return (0 == retval);
 }

libraries/CurieBLE/src/internal/BLECharacteristicImp.h

@@ -168,6 +168,10 @@ class BLECharacteristicImp: public BLEAttribute{
      */
     bool write(const unsigned char value[], 
                uint16_t length);
+    
+    static void writeResponseReceived(struct bt_conn *conn, 
+                                      uint8_t err,
+                                      const void *data);
 
     int descriptorCount() const;
     uint8_t discoverResponseProc(bt_conn_t *conn,
@@ -325,6 +329,7 @@ class BLECharacteristicImp: public BLEAttribute{
     bool        _subscribed;
 
     bool _reading;
+    static volatile bool _gattc_writing;
     bt_gatt_read_params_t _read_params; // GATT read parameter
 
     typedef LinkNode<BLEDescriptorImp *>  BLEDescriptorLinkNodeHeader;