add ble connection interval and ble TX flush interval

Author: soundanalogous

examples/StandardFirmataBLE/StandardFirmataBLE.ino

@@ -20,7 +20,7 @@
 
   See file LICENSE.txt for further informations on licensing terms.
 
-  Last updated by Jeff Hoefs: February 27th, 2016
+  Last updated by Jeff Hoefs: March 5th, 2016
 */
 
 #include <Servo.h>
@@ -47,6 +47,9 @@
 // the minimum interval for sampling analog input
 #define MINIMUM_SAMPLING_INTERVAL   1
 
+// min cannot be < 0x0006. Adjust max if necessary
+#define FIRMATA_BLE_MIN_INTERVAL    0x0006 // 7.5ms (7.5 / 1.25)
+#define FIRMATA_BLE_MAX_INTERVAL    0x0018 // 30ms (30 / 1.25)
 
 /*==============================================================================
  * GLOBAL VARIABLES
@@ -751,7 +754,12 @@ void setup()
   Firmata.attach(START_SYSEX, sysexCallback);
   Firmata.attach(SYSTEM_RESET, systemResetCallback);
 
-  stream.setLocalName("FIRMATA");
+  stream.setLocalName(FIRMATA_BLE_LOCAL_NAME);
+
+  // set the BLE connection interval - this is the fastest interval you can read inputs
+  stream.setConnectionInterval(FIRMATA_BLE_MIN_INTERVAL, FIRMATA_BLE_MAX_INTERVAL);
+  // set how often the BLE TX buffer is flushed (if not full)
+  stream.setFlushInterval(FIRMATA_BLE_MAX_INTERVAL);
 
 #ifdef BLE_REQ
   for (byte i = 0; i < TOTAL_PINS; i++) {
@@ -775,7 +783,7 @@ void loop()
   byte pin, analogPin;
 
   // do not process data if no BLE connection is established
-  // poll will send the TX buffer every 30ms while it contains data
+  // poll will send the TX buffer at the specified flush interval or when the buffer is full
   if (!stream.poll()) return;
 
   /* DIGITALREAD - as fast as possible, check for changes and output them to the

examples/StandardFirmataBLE/bleConfig.h

@@ -1,16 +1,20 @@
-/*===================================================================================
+/*==================================================================================================
  * BLE CONFIGURATION
  *
- * If you are using an Arduino 101, you do not need to make any changes to this
- * file. If you are using another supported BLE board or shield, follow the
- * instructions for the specific board or shield below.
+ * If you are using an Arduino 101, you do not need to make any changes to this file (unless you
+ * need a unique ble local name (see below). If you are using another supported BLE board or shield,
+ * follow the instructions for the specific board or shield below.
  *
  * Supported boards and shields:
  * - Arduino 101 (recommended)
  * - RedBearLab BLE Shield (v2)  ** to be verified **
  * - RedBearLab BLE Nano ** works with modifications **
  *
- *==================================================================================*/
+ *================================================================================================*/
+
+// change this to a unique name per board if running StandardFirmataBLE on multiple boards
+// within the same physical space
+#define FIRMATA_BLE_LOCAL_NAME "FIRMATA"
 
 /*
  * RedBearLab BLE Shield
@@ -42,18 +46,17 @@ BLEStream stream(BLE_REQ, BLE_RDY, BLE_RST);
 #endif
 
 
-/*===================================================================================
+/*==================================================================================================
  * END BLE CONFIGURATION - you should not need to change anything below this line
- *==================================================================================*/
+ *================================================================================================*/
 
 /*
  * Arduino 101
  *
  * Test script: https://gist.github.com/soundanalogous/927360b797574ed50e27
  */
 #ifdef _VARIANT_ARDUINO_101_X_
-#include <CurieBle.h>
-//#include <CurieBLE.h> // switch to this once new Arduino 101 board package is available
+#include <CurieBLE.h>
 #include "utility/BLEStream.h"
 BLEStream stream;
 #endif

utility/BLEStream.cpp

@@ -4,7 +4,7 @@
   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
+  Last updated by Jeff Hoefs: March 5th, 2016
  */
 
 #include "BLEStream.h"
@@ -23,6 +23,7 @@ BLEStream::BLEStream(unsigned char req, unsigned char rdy, unsigned char rst) :
   this->_txCount = 0;
   this->_rxHead = this->_rxTail = 0;
   this->_flushed = 0;
+  this->_flushInterval = BLESTREAM_TXBUFFER_FLUSH_INTERVAL;
   BLEStream::_instance = this;
 
   addAttribute(this->_uartService);
@@ -47,7 +48,7 @@ bool BLEStream::poll()
 {
   // BLEPeripheral::poll is called each time connected() is called
   this->_connected = BLEPeripheral::connected();
-  if (millis() > this->_flushed + BLESTREAM_TXBUFFER_FLUSH_INTERVAL) {
+  if (millis() > this->_flushed + this->_flushInterval) {
     flush();
   }
   return this->_connected;
@@ -151,6 +152,13 @@ BLEStream::operator bool()
   return retval;
 }
 
+void BLEStream::setFlushInterval(int interval)
+{
+  if (interval > BLESTREAM_MIN_FLUSH_INTERVAL) {
+    this->_flushInterval = interval;
+  }
+}
+
 void BLEStream::_received(const unsigned char* data, size_t size)
 {
   for (size_t i = 0; i < size; i++) {

utility/BLEStream.h

@@ -4,16 +4,15 @@
   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
+  Last updated by Jeff Hoefs: March 5th, 2016
  */
 
 #ifndef _BLE_STREAM_H_
 #define _BLE_STREAM_H_
 
 #include <Arduino.h>
 #if defined(_VARIANT_ARDUINO_101_X_)
-#include <CurieBle.h>
-//#include <CurieBLE.h> // switch to this once new Arduino 101 board package is available
+#include <CurieBLE.h>
 #define _MAX_ATTR_DATA_LEN_ BLE_MAX_ATTR_DATA_LEN
 #else
 #include <BLEPeripheral.h>
@@ -25,6 +24,7 @@
 #else
 #define BLESTREAM_TXBUFFER_FLUSH_INTERVAL 80
 #endif
+#define BLESTREAM_MIN_FLUSH_INTERVAL 8 // minimum interval for flushing the TX buffer
 
 class BLEStream : public BLEPeripheral, public Stream
 {
@@ -34,6 +34,7 @@ class BLEStream : public BLEPeripheral, public Stream
     void begin(...);
     bool poll();
     void end();
+    void setFlushInterval(int);
 
     virtual int available(void);
     virtual int peek(void);
@@ -46,6 +47,7 @@ class BLEStream : public BLEPeripheral, public Stream
   private:
     bool _connected;
     unsigned long _flushed;
+    int _flushInterval;
     static BLEStream* _instance;
 
     size_t _rxHead;