CurieI2S add examples

-add basic examples using callback functions/interrupts
-add callback function to fill tx buffer

Author: bigdinotech

libraries/CurieI2S/examples/I2S_RxCallback/I2S_RxCallback.ino

@@ -0,0 +1,53 @@
+/**
+ * A simple sketch to test the rx channel of the i2s interface. 
+ * A callback function is used to fill up a buffer whenever data is received
+ * 
+ * To test this sketch you will need a second Arduino/Genuino 101 board with the I2S_TxCallback sketch uploaded
+ * 
+ * Connection:
+ * I2S_RSCK(pin 8) -> I2S_TSCK(pin 2) 
+ * I2S_RWS(pin 3) -> I2S_TWS(pin 4)
+ * I2S_RXD(pin 5) -> I2S_TXD(pin 7)
+ * 
+**/
+#include <CurieI2S.h>
+
+uint32_t dataBuff[256];
+volatile int count = 0;
+
+void setup() 
+{
+  // put your setup code here, to run once:
+  Serial.begin(115200);
+  while(!Serial);
+  Serial.println("CurieI2S Rx Callback Example");
+  CurieI2S.begin(I2S_44K, I2S_32bit);
+  CurieI2S.setI2SMode(PHILIPS_MODE);
+  CurieI2S.attachRxInterrupt(rxDataReceived);
+  CurieI2S.initRX();
+  CurieI2S.startRX();
+
+}
+
+void loop() 
+{
+  if(count>0)
+  {
+    for(int i =0; i < count; i++)
+    {
+      Serial.print("data: ");
+      Serial.println(dataBuff[i], HEX);
+    }
+    count = 0;
+  }
+  delay(500);
+}
+
+//This function is called inside an ISR so it is important to make this as atomic/fast as possible
+void rxDataReceived()
+{
+  while(CurieI2S.available())
+  {
+    dataBuff[count++] =  CurieI2S.requestdword();   
+  }
+}

libraries/CurieI2S/examples/I2S_TxCallback/I2S_TxCallback.ino

@@ -0,0 +1,56 @@
+#include <CurieI2S.h>
+
+//I2S_TX -> Pin 7
+//I2S_TSK -> Pin 4
+//I2S_TSCK -> pin 2
+
+void setup() 
+{
+  Serial.begin(115200);
+  while(!Serial);
+  Serial.println("CurieI2S Tx Callback");
+  CurieI2S.begin(I2S_44K, I2S_32bit);
+  CurieI2S.setI2SMode(PHILIPS_MODE);
+  CurieI2S.attachTxEmptyInterrupt(doneTX);
+  CurieI2S.attachTxInterrupt(fillTxBuffer);
+  CurieI2S.initTX();
+}
+
+void loop() 
+{
+  Serial.println("+++");
+
+  //start filling the tx buffer
+  CurieI2S.pushData(0xFFFFFFFF);
+  CurieI2S.pushData(0x00000000);
+  CurieI2S.pushData(0xDEADFACE);
+  CurieI2S.pushData(0x10101010);
+  Serial.println("start transmitting");
+  //Start Transmission
+  CurieI2S.startTX(); 
+  for(int i = 0; i < 40; i++)
+  {
+    //keep filling the buffer
+    while(!CurieI2S.pushData(0xFFFFFFFF));
+    while(!CurieI2S.pushData(0x00000000));
+    while(!CurieI2S.pushData(0xDEADFACE));
+    while(!CurieI2S.pushData(0x10101010));
+  }
+  //Tx is automatically stopped after the tx buffer is emptied
+  
+  delay(500);
+  Serial.println("+++");
+}
+
+void doneTX()
+{
+  Serial.println("done transmitting");
+}
+
+void fillTxBuffer()
+{
+  //you can fill the tx buffer here if you want
+  //CurieI2S.pushData(0xDEADDEAD);
+  //CurieI2S.pushData(0xDEADFACE);
+}
+

libraries/CurieI2S/src/CurieI2S.cpp

@@ -47,7 +47,7 @@ static void i2sInterruptHandler(void)
         //Serial.println("rx almost full");
 
         //disable RFIFO_AFULL interrupts
-        *I2S_CID_CTRL = *I2S_CID_CTRL & 0x7FFFFFFF;
+        //*I2S_CID_CTRL = *I2S_CID_CTRL & 0x7FFFFFFF;
 
         int index;
         int fifoDataLength = (*I2S_RFIFO_STAT & 0x0000000F);
@@ -67,7 +67,7 @@ static void i2sInterruptHandler(void)
             #endif
 
         }
-        
+            
         //enable RFIFO_EMPTY interrupt
         *I2S_CID_CTRL = *I2S_CID_CTRL | 0x10000000;
 
@@ -124,6 +124,9 @@ static void i2sInterruptHandler(void)
         //digitalWrite(I2S_DEBUG_PIN, LOW);
         #endif
 
+        //call tx callback
+        CurieI2S.i2s_tx_callback();
+        
         if(_i2s_Tx_BufferPtr->head != _i2s_Tx_BufferPtr->tail)
         {
             int index = _i2s_Tx_BufferPtr->tail;
@@ -227,8 +230,8 @@ static void i2sInterruptHandler(void)
                 i2s_stat = i2s_stat & 0xFFFFF0FF;
                 *I2S_STAT = i2s_stat | 0x00000001;
 
-                //call rx callback
-                CurieI2S.i2s_tx_callback();
+                //call tx empty callback
+                CurieI2S.i2s_tx_empty_callback();
 
                 //enable TFIFO_AEMPTY and TFIFO_FULL interrupts
                 *I2S_CID_CTRL = *I2S_CID_CTRL | 0x06000000;
@@ -263,8 +266,9 @@ static void i2sInterruptHandler(void)
 
 Curie_I2S::Curie_I2S()
 {
-    i2s_txCB = NULL;
     i2s_rxCB = NULL;
+    i2s_txEmptyCB = NULL;
+    i2s_txCB = NULL;
 }
 
 void Curie_I2S::begin(uint32_t sampleRate, uint32_t resolution)
@@ -391,7 +395,7 @@ void Curie_I2S::init()
     *I2S_CTRL = i2s_ctrl;
 
     //set threshold for FIFOs
-    *I2S_TFIFO_CTRL |= 0x00030003;
+    *I2S_TFIFO_CTRL |= 0x00030002;
     *I2S_RFIFO_CTRL |= 0x00010002;
 
     //enable interrupts
@@ -633,6 +637,11 @@ void Curie_I2S::attachRxInterrupt(void (*userCallBack)())
     i2s_rxCB = userCallBack;
 }
 
+void Curie_I2S::attachTxEmptyInterrupt(void (*userCallBack)())
+{
+    i2s_txEmptyCB = userCallBack;
+}
+
 void Curie_I2S::attachTxInterrupt(void (*userCallBack)())
 {
     i2s_txCB = userCallBack;
@@ -644,6 +653,12 @@ inline void Curie_I2S::i2s_rx_callback(void)
         i2s_rxCB();
 }
 
+inline void Curie_I2S::i2s_tx_empty_callback(void)
+{
+    if(i2s_txEmptyCB != NULL)
+        i2s_txEmptyCB();
+}
+
 inline void Curie_I2S::i2s_tx_callback(void)
 {
     if(i2s_txCB != NULL)

libraries/CurieI2S/src/CurieI2S.h

@@ -128,9 +128,11 @@ class Curie_I2S
         //enables i2s interrupts
         void enableInterrupts();
 
+        void (*i2s_rxCB)();
+        
         void (*i2s_txCB)();
 
-        void (*i2s_rxCB)();
+        void (*i2s_txEmptyCB)();
 
     public:
         Curie_I2S();
@@ -200,21 +202,29 @@ class Curie_I2S
 
         uint8_t getRxFIFOLength();
 
-        // Attach user callback when there is data pushed into the rx buffer from the RX_FIFO
+        // Attach user callback that is triggered when there is data pushed into the rx buffer from the RX_FIFO
         void attachRxInterrupt(void (*userCallBack)());
 
         void detachRxInterrupt(void) { return attachTxInterrupt(NULL); };
 
-        // Attach user callback when that gets called when TX_FIFO is empty(transmission done);
+        // Attach user callback that is triggered when that gets called when TX_FIFO is empty(transmission done);
+        void attachTxEmptyInterrupt(void (*userCallBack)());
+        
+        void detachTxEmptyInterrupt(void) { return attachTxEmptyInterrupt(NULL); };
+        
+        // Attach user callback that is triggered when that gets called when TX_FIFO has available space;
         void attachTxInterrupt(void (*userCallBack)());
 
-        void detachTxInterrupt(void) { return attachRxInterrupt(NULL); };
+        void detachTxInterrupt(void) { return attachTxInterrupt(NULL); };
+        
+        //rx callback
+        void i2s_rx_callback(void);
 
         //tx callback
         void i2s_tx_callback(void);
 
-        //rx callback
-        void i2s_rx_callback(void);
+        //tx empty callback
+        void i2s_tx_empty_callback(void);
 };
 
 extern Curie_I2S CurieI2S;