Added support for the Adafruit Feather M0 Bluefruit LE (and potentially other Bluefruit LE boards/modules that communicate with the nRF51822 via SPI) to StandardFirmataBLE

Author: cstawarz

examples/StandardFirmataBLE/StandardFirmataBLE.ino

@@ -768,7 +768,7 @@ void setup()
   Firmata.attach(START_SYSEX, sysexCallback);
   Firmata.attach(SYSTEM_RESET, systemResetCallback);
 
-#ifdef BLE_REQ
+#ifdef IS_IGNORE_BLE_PINS
   for (byte i = 0; i < TOTAL_PINS; i++) {
     if (IS_IGNORE_BLE_PINS(i)) {
       Firmata.setPinMode(i, PIN_MODE_IGNORE);

examples/StandardFirmataBLE/bleConfig.h

@@ -12,6 +12,7 @@
  * - Arduino 101 (recommended)
  * - RedBearLab BLE Shield (v2)  ** to be verified **
  * - RedBearLab BLE Nano ** works with modifications **
+ * - Adafruit Feather M0 Bluefruit LE
  *
  *================================================================================================*/
 
@@ -58,6 +59,31 @@
 #endif
 
 
+/*
+ * Adafruit Feather M0 Bluefruit LE
+ *
+ * If you are using an Adafruit Feather M0 Bluefruit LE, uncomment the define below.
+ * This configuration should also work with other Bluefruit LE boards/modules that communicate
+ * with the nRF51822 via SPI (e.g. Bluefruit LE SPI Friend, Bluefruit LE Shield), although
+ * you may need to change the values of BLE_SPI_CS, BLE_SPI_IRQ, and/or BLE_SPI_RST below.
+ *
+ * You will need to install a lightly-modified version of the Adafruit BluefruitLE nRF51
+ * package, available at:
+ * https://github.com/cstawarz/Adafruit_BluefruitLE_nRF51/archive/firmata_fixes.zip
+ */
+//#define BLUEFRUIT_LE_SPI
+
+#ifdef BLUEFRUIT_LE_SPI
+// Both values must be between 10ms and 4s
+#define FIRMATA_BLE_MIN_INTERVAL 10 // 10ms
+#define FIRMATA_BLE_MAX_INTERVAL 20 // 20ms
+
+#define BLE_SPI_CS   8
+#define BLE_SPI_IRQ  7
+#define BLE_SPI_RST  4
+#endif
+
+
 /*
  * Generic settings
  */
@@ -93,6 +119,12 @@ BLEStream stream(BLE_REQ, BLE_RDY, BLE_RST);
 #endif
 
 
+#ifdef BLUEFRUIT_LE_SPI
+#include "utility/BluefruitLE_SPI_Stream.h"
+BluefruitLE_SPI_Stream stream(BLE_SPI_CS, BLE_SPI_IRQ, BLE_SPI_RST);
+#endif
+
+
 /*
  * RedBearLab BLE Nano (with default switch settings)
  *
@@ -133,4 +165,6 @@ BLEStream stream(BLE_REQ, BLE_RDY, BLE_RST);
 
 #if defined(BLE_REQ) && defined(BLE_RDY) && defined(BLE_RST)
 #define IS_IGNORE_BLE_PINS(p) ((p) == BLE_REQ || (p) == BLE_RDY || (p) == BLE_RST)
+#elif defined(BLE_SPI_CS) && defined(BLE_SPI_IRQ) && defined(BLE_SPI_RST)
+#define IS_IGNORE_BLE_PINS(p) ((p) == BLE_SPI_CS || (p) == BLE_SPI_IRQ || (p) == BLE_SPI_RST)
 #endif

utility/BluefruitLE_SPI_Stream.cpp

@@ -0,0 +1,3 @@
+/*
+ * Implementation is in BluefruitLE_SPI_Stream.h to avoid linker issues.
+ */

utility/BluefruitLE_SPI_Stream.h

@@ -0,0 +1,127 @@
+/*
+  BluefruitLE_SPI_Stream.h
+
+  Documentation for the various AT commands used below is available at
+  https://learn.adafruit.com/adafruit-feather-m0-bluefruit-le/at-commands
+ */
+
+#ifndef _BLUEFRUIT_LE_SPI_STREAM_H_
+#define _BLUEFRUIT_LE_SPI_STREAM_H_
+
+#include <Adafruit_BluefruitLE_SPI.h>
+
+
+class BluefruitLE_SPI_Stream : public Stream
+{
+  public:
+    BluefruitLE_SPI_Stream(int8_t csPin, int8_t irqPin, int8_t rstPin);
+
+    void begin();
+    bool poll();
+    void end();
+
+    // Print overrides
+    size_t write(uint8_t byte);
+    using Print::write;  // Expose other write variants
+
+    // Stream overrides
+    int available();
+    int read();
+    int peek();
+    void flush();
+
+  private:
+    Adafruit_BluefruitLE_SPI ble;
+
+    uint8_t txBuffer[SDEP_MAX_PACKETSIZE];
+    size_t txCount;
+};
+
+
+BluefruitLE_SPI_Stream::BluefruitLE_SPI_Stream(int8_t csPin, int8_t irqPin, int8_t rstPin) :
+  ble(csPin, irqPin, rstPin),
+  txCount(0)
+{ }
+
+void BluefruitLE_SPI_Stream::begin()
+{
+  // Initialize the SPI interface
+  ble.begin();
+
+  // Perform a factory reset to make sure everything is in a known state
+  ble.factoryReset();
+
+  // Disable command echo from Bluefruit
+  ble.echo(false);
+
+  // Change the MODE LED to indicate BLE UART activity
+  ble.println("AT+HWMODELED=BLEUART");
+
+  // Set local name
+  ble.print("AT+GAPDEVNAME=");
+  ble.println(FIRMATA_BLE_LOCAL_NAME);
+
+  // Set connection interval
+  ble.print("AT+GAPINTERVALS=");
+  ble.print(FIRMATA_BLE_MIN_INTERVAL);
+  ble.print(",");
+  ble.print(FIRMATA_BLE_MAX_INTERVAL);
+  ble.println(",,,");
+
+  // Disable real and simulated mode switch (i.e. "+++") command
+  ble.println("AT+MODESWITCHEN=local,0");
+  ble.enableModeSwitchCommand(false);
+
+  // Switch to data mode
+  ble.setMode(BLUEFRUIT_MODE_DATA);
+}
+
+bool BluefruitLE_SPI_Stream::poll()
+{
+  // If there's outgoing data in the buffer, just send it.  The firmware on
+  // the nRF51822 will decide when to transmit the data in its TX FIFO.
+  if (txCount) flush();
+
+  // In order to check for a connection, we would need to switch from data to
+  // command mode and back again.  However, due to the internal workings of
+  // Adafruit_BluefruitLE_SPI, this can lead to unread incoming data being
+  // lost.  Therefore, we always return true.
+  return true;
+}
+
+void BluefruitLE_SPI_Stream::end()
+{
+  flush();
+  ble.end();
+}
+
+size_t BluefruitLE_SPI_Stream::write(uint8_t byte)
+{
+  txBuffer[txCount++] = byte;
+  if (txCount == sizeof(txBuffer)) flush();
+  return 1;
+}
+
+int BluefruitLE_SPI_Stream::available()
+{
+  return ble.available();
+}
+
+int BluefruitLE_SPI_Stream::read()
+{
+  return ble.read();
+}
+
+int BluefruitLE_SPI_Stream::peek()
+{
+  return ble.peek();
+}
+
+void BluefruitLE_SPI_Stream::flush()
+{
+  ble.write(txBuffer, txCount);
+  txCount = 0;
+}
+
+
+#endif // _BLUEFRUIT_LE_SPI_STREAM_H_