proper check for available packets

Author: soundanalogous

utility/BLEStream.cpp

@@ -3,6 +3,8 @@
 
   Based on BLESerial.cpp by Voita Molda
   https://github.com/sandeepmistry/arduino-BLEPeripheral/blob/master/examples/serial/BLESerial.cpp
+
+  Last updated by Jeff Hoefs: February 28th, 2016
  */
 
 #include "BLEStream.h"
@@ -21,7 +23,6 @@ BLEStream::BLEStream(unsigned char req, unsigned char rdy, unsigned char rst) :
   this->_txCount = 0;
   this->_rxHead = this->_rxTail = 0;
   this->_flushed = 0;
-  this->_packetTxCount = 0;
   BLEStream::_instance = this;
 
   addAttribute(this->_uartService);
@@ -111,21 +112,9 @@ void BLEStream::flush(void)
 {
   if (this->_txCount == 0) return;
 #ifndef _VARIANT_ARDUINO_101_X_
-  long diff = millis() - this->_flushed;
-  // flush() is called approximately every 1ms or less when sending multiple packets and
-  // otherwise no more frequently than BLESTREAM_TXBUFFER_FLUSH_INTERVAL
-  // TODO - determine if 2 is the best value or if something higher is necessary
-  if (diff < 2) {
-    // 2 is the max number of packets that can be sent in short succession
-    // TODO - get the max packet value programatically
-    if (++this->_packetTxCount >= 2) {
-      // delay after 2 packets have been sent in short succession
-      // 100ms is the minimum necessary delay value
-      delay(100);
-      this->_packetTxCount = 0;
-    }
-  } else {
-    this->_packetTxCount = 0;
+  // ensure there are available packets before sending
+  while(!this->_txCharacteristic.canNotify()) {
+    BLEPeripheral::poll();
   }
 #endif
   this->_txCharacteristic.setValue(this->_txBuffer, this->_txCount);

utility/BLEStream.h

@@ -3,6 +3,8 @@
 
   Based on BLESerial.cpp by Voita Molda
   https://github.com/sandeepmistry/arduino-BLEPeripheral/blob/master/examples/serial/BLESerial.h
+
+  Last updated by Jeff Hoefs: February 28th, 2016
  */
 
 #ifndef _BLE_STREAM_H_
@@ -53,8 +55,6 @@ class BLEStream : public BLEPeripheral, public Stream
     size_t _txCount;
     unsigned char _txBuffer[_MAX_ATTR_DATA_LEN_];
 
-    uint8_t _packetTxCount;
-
     BLEService _uartService = BLEService("6E400001-B5A3-F393-E0A9-E50E24DCCA9E");
     BLEDescriptor _uartNameDescriptor = BLEDescriptor("2901", "UART");
     BLECharacteristic _rxCharacteristic = BLECharacteristic("6E400002-B5A3-F393-E0A9-E50E24DCCA9E", BLEWriteWithoutResponse, _MAX_ATTR_DATA_LEN_);