Revision 3:e6a29c83ac52, committed 2011-12-19

Comitter:

samux

Date:

Mon Dec 19 15:46:17 2011 +0000

Parent:

2:7d8bdeb3753b

Child:

4:bef3b485f22e

Commit message:

ok we can send a music from an sdcard but readings are time to time slow...

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/FATFileSystem.lib	Mon Dec 19 15:46:17 2011 +0000
@@ -0,0 +1,1 @@
+http://mbed.co.uk/projects/libraries/svn/FATFileSystem/trunk@26
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SDFileSystem/.lib	Mon Dec 19 15:46:17 2011 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/simon/programs/SDFileSystem/5yj8f
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SDFileSystem/SDFileSystem.cpp	Mon Dec 19 15:46:17 2011 +0000
@@ -0,0 +1,457 @@
+/* mbed SDFileSystem Library, for providing file access to SD cards
+ * Copyright (c) 2008-2010, sford
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/* Introduction
+ * ------------
+ * SD and MMC cards support a number of interfaces, but common to them all
+ * is one based on SPI. This is the one I'm implmenting because it means
+ * it is much more portable even though not so performant, and we already 
+ * have the mbed SPI Interface!
+ *
+ * The main reference I'm using is Chapter 7, "SPI Mode" of: 
+ *  http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf
+ *
+ * SPI Startup
+ * -----------
+ * The SD card powers up in SD mode. The SPI interface mode is selected by
+ * asserting CS low and sending the reset command (CMD0). The card will 
+ * respond with a (R1) response.
+ *
+ * CMD8 is optionally sent to determine the voltage range supported, and 
+ * indirectly determine whether it is a version 1.x SD/non-SD card or 
+ * version 2.x. I'll just ignore this for now.
+ *
+ * ACMD41 is repeatedly issued to initialise the card, until "in idle"
+ * (bit 0) of the R1 response goes to '0', indicating it is initialised.
+ *
+ * You should also indicate whether the host supports High Capicity cards,
+ * and check whether the card is high capacity - i'll also ignore this
+ *
+ * SPI Protocol
+ * ------------
+ * The SD SPI protocol is based on transactions made up of 8-bit words, with
+ * the host starting every bus transaction by asserting the CS signal low. The
+ * card always responds to commands, data blocks and errors.
+ * 
+ * The protocol supports a CRC, but by default it is off (except for the 
+ * first reset CMD0, where the CRC can just be pre-calculated, and CMD8)
+ * I'll leave the CRC off I think! 
+ * 
+ * Standard capacity cards have variable data block sizes, whereas High 
+ * Capacity cards fix the size of data block to 512 bytes. I'll therefore
+ * just always use the Standard Capacity cards with a block size of 512 bytes.
+ * This is set with CMD16.
+ *
+ * You can read and write single blocks (CMD17, CMD25) or multiple blocks 
+ * (CMD18, CMD25). For simplicity, I'll just use single block accesses. When
+ * the card gets a read command, it responds with a response token, and then 
+ * a data token or an error.
+ * 
+ * SPI Command Format
+ * ------------------
+ * Commands are 6-bytes long, containing the command, 32-bit argument, and CRC.
+ *
+ * +---------------+------------+------------+-----------+----------+--------------+
+ * | 01 | cmd[5:0] | arg[31:24] | arg[23:16] | arg[15:8] | arg[7:0] | crc[6:0] | 1 |
+ * +---------------+------------+------------+-----------+----------+--------------+
+ *
+ * As I'm not using CRC, I can fix that byte to what is needed for CMD0 (0x95)
+ *
+ * All Application Specific commands shall be preceded with APP_CMD (CMD55).
+ *
+ * SPI Response Format
+ * -------------------
+ * The main response format (R1) is a status byte (normally zero). Key flags:
+ *  idle - 1 if the card is in an idle state/initialising 
+ *  cmd  - 1 if an illegal command code was detected
+ *
+ *    +-------------------------------------------------+
+ * R1 | 0 | arg | addr | seq | crc | cmd | erase | idle |
+ *    +-------------------------------------------------+
+ *
+ * R1b is the same, except it is followed by a busy signal (zeros) until
+ * the first non-zero byte when it is ready again.
+ *
+ * Data Response Token
+ * -------------------
+ * Every data block written to the card is acknowledged by a byte 
+ * response token
+ *
+ * +----------------------+
+ * | xxx | 0 | status | 1 |
+ * +----------------------+
+ *              010 - OK!
+ *              101 - CRC Error
+ *              110 - Write Error
+ *
+ * Single Block Read and Write
+ * ---------------------------
+ *
+ * Block transfers have a byte header, followed by the data, followed
+ * by a 16-bit CRC. In our case, the data will always be 512 bytes.
+ *  
+ * +------+---------+---------+- -  - -+---------+-----------+----------+
+ * | 0xFE | data[0] | data[1] |        | data[n] | crc[15:8] | crc[7:0] | 
+ * +------+---------+---------+- -  - -+---------+-----------+----------+
+ */
+ 
+#include "SDFileSystem.h"
+
+#define SD_COMMAND_TIMEOUT 5000
+
+SDFileSystem::SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name) :
+  FATFileSystem(name), _spi(mosi, miso, sclk), _cs(cs) {
+      _cs = 1; 
+}
+
+#define R1_IDLE_STATE           (1 << 0)
+#define R1_ERASE_RESET          (1 << 1)
+#define R1_ILLEGAL_COMMAND      (1 << 2)
+#define R1_COM_CRC_ERROR        (1 << 3)
+#define R1_ERASE_SEQUENCE_ERROR (1 << 4)
+#define R1_ADDRESS_ERROR        (1 << 5)
+#define R1_PARAMETER_ERROR      (1 << 6)
+
+// Types
+//  - v1.x Standard Capacity
+//  - v2.x Standard Capacity
+//  - v2.x High Capacity
+//  - Not recognised as an SD Card
+
+#define SDCARD_FAIL 0
+#define SDCARD_V1   1
+#define SDCARD_V2   2
+#define SDCARD_V2HC 3
+
+int SDFileSystem::initialise_card() {
+    // Set to 100kHz for initialisation, and clock card with cs = 1
+    _spi.frequency(100000); 
+    _cs = 1;
+    for(int i=0; i<16; i++) {   
+        _spi.write(0xFF);
+    }
+
+    // send CMD0, should return with all zeros except IDLE STATE set (bit 0)
+    if(_cmd(0, 0) != R1_IDLE_STATE) { 
+        fprintf(stderr, "No disk, or could not put SD card in to SPI idle state\n");
+        return SDCARD_FAIL;
+    }
+
+    // send CMD8 to determine whther it is ver 2.x
+    int r = _cmd8();
+    if(r == R1_IDLE_STATE) {
+        return initialise_card_v2();
+    } else if(r == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) {
+        return initialise_card_v1();
+    } else {
+        fprintf(stderr, "Not in idle state after sending CMD8 (not an SD card?)\n");
+        return SDCARD_FAIL;
+    }
+}
+
+int SDFileSystem::initialise_card_v1() {
+    for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
+        _cmd(55, 0); 
+        if(_cmd(41, 0) == 0) { 
+            return SDCARD_V1;
+        }
+    }
+
+    fprintf(stderr, "Timeout waiting for v1.x card\n");
+    return SDCARD_FAIL;
+}
+
+int SDFileSystem::initialise_card_v2() {
+    
+    for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
+        _cmd(55, 0); 
+        if(_cmd(41, 0) == 0) { 
+            _cmd58();
+            return SDCARD_V2;
+        }
+    }
+
+    fprintf(stderr, "Timeout waiting for v2.x card\n");
+    return SDCARD_FAIL;
+}
+
+int SDFileSystem::disk_initialize() {
+
+    int i = initialise_card();
+//    printf("init card = %d\n", i);
+//    printf("OK\n");
+
+    _sectors = _sd_sectors();
+
+    // Set block length to 512 (CMD16)
+    if(_cmd(16, 512) != 0) {
+        fprintf(stderr, "Set 512-byte block timed out\n");
+        return 1;
+    }
+        
+    _spi.frequency(1000000); // Set to 1MHz for data transfer
+    return 0;
+}
+
+int SDFileSystem::disk_write(const char *buffer, int block_number) {
+    // set write address for single block (CMD24)
+    if(_cmd(24, block_number * 512) != 0) {
+        return 1;
+    }
+
+    // send the data block
+    _write(buffer, 512);    
+    return 0;    
+}
+
+int SDFileSystem::disk_read(char *buffer, int block_number) {        
+    // set read address for single block (CMD17)
+    if(_cmd(17, block_number * 512) != 0) {
+        return 1;
+    }
+    
+    // receive the data
+    _read(buffer, 512);
+    return 0;
+}
+
+int SDFileSystem::disk_status() { return 0; }
+int SDFileSystem::disk_sync() { return 0; }
+int SDFileSystem::disk_sectors() { return _sectors; }
+
+// PRIVATE FUNCTIONS
+
+int SDFileSystem::_cmd(int cmd, int arg) {
+    _cs = 0; 
+
+    // send a command
+    _spi.write(0x40 | cmd);
+    _spi.write(arg >> 24);
+    _spi.write(arg >> 16);
+    _spi.write(arg >> 8);
+    _spi.write(arg >> 0);
+    _spi.write(0x95);
+
+    // wait for the repsonse (response[7] == 0)
+    for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
+        int response = _spi.write(0xFF);
+        if(!(response & 0x80)) {
+            _cs = 1;
+            _spi.write(0xFF);
+            return response;
+        }
+    }
+    _cs = 1;
+    _spi.write(0xFF);
+    return -1; // timeout
+}
+int SDFileSystem::_cmdx(int cmd, int arg) {
+    _cs = 0; 
+
+    // send a command
+    _spi.write(0x40 | cmd);
+    _spi.write(arg >> 24);
+    _spi.write(arg >> 16);
+    _spi.write(arg >> 8);
+    _spi.write(arg >> 0);
+    _spi.write(0x95);
+
+    // wait for the repsonse (response[7] == 0)
+    for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
+        int response = _spi.write(0xFF);
+        if(!(response & 0x80)) {
+            return response;
+        }
+    }
+    _cs = 1;
+    _spi.write(0xFF);
+    return -1; // timeout
+}
+
+
+int SDFileSystem::_cmd58() {
+    _cs = 0; 
+    int arg = 0;
+    
+    // send a command
+    _spi.write(0x40 | 58);
+    _spi.write(arg >> 24);
+    _spi.write(arg >> 16);
+    _spi.write(arg >> 8);
+    _spi.write(arg >> 0);
+    _spi.write(0x95);
+
+    // wait for the repsonse (response[7] == 0)
+    for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
+        int response = _spi.write(0xFF);
+        if(!(response & 0x80)) {
+            int ocr = _spi.write(0xFF) << 24;
+            ocr |= _spi.write(0xFF) << 16;
+            ocr |= _spi.write(0xFF) << 8;
+            ocr |= _spi.write(0xFF) << 0;
+//            printf("OCR = 0x%08X\n", ocr);
+            _cs = 1;
+            _spi.write(0xFF);
+            return response;
+        }
+    }
+    _cs = 1;
+    _spi.write(0xFF);
+    return -1; // timeout
+}
+
+int SDFileSystem::_cmd8() {
+    _cs = 0; 
+    
+    // send a command
+    _spi.write(0x40 | 8); // CMD8
+    _spi.write(0x00);     // reserved
+    _spi.write(0x00);     // reserved
+    _spi.write(0x01);     // 3.3v
+    _spi.write(0xAA);     // check pattern
+    _spi.write(0x87);     // crc
+
+    // wait for the repsonse (response[7] == 0)
+    for(int i=0; i<SD_COMMAND_TIMEOUT * 1000; i++) {
+        char response[5];
+        response[0] = _spi.write(0xFF);
+        if(!(response[0] & 0x80)) {
+                for(int j=1; j<5; j++) {
+                    response[i] = _spi.write(0xFF);
+                }
+                _cs = 1;
+                _spi.write(0xFF);
+                return response[0];
+        }
+    }
+    _cs = 1;
+    _spi.write(0xFF);
+    return -1; // timeout
+}
+
+int SDFileSystem::_read(char *buffer, int length) {
+    _cs = 0;
+
+    // read until start byte (0xFF)
+    while(_spi.write(0xFF) != 0xFE);
+
+    // read data
+    for(int i=0; i<length; i++) {
+        buffer[i] = _spi.write(0xFF);
+    }
+    _spi.write(0xFF); // checksum
+    _spi.write(0xFF);
+
+    _cs = 1;    
+    _spi.write(0xFF);
+    return 0;
+}
+
+int SDFileSystem::_write(const char *buffer, int length) {
+    _cs = 0;
+    
+    // indicate start of block
+    _spi.write(0xFE);
+    
+    // write the data
+    for(int i=0; i<length; i++) {
+        _spi.write(buffer[i]);
+    }
+    
+    // write the checksum
+    _spi.write(0xFF); 
+    _spi.write(0xFF);
+
+    // check the repsonse token
+    if((_spi.write(0xFF) & 0x1F) != 0x05) {
+        _cs = 1;
+        _spi.write(0xFF);        
+        return 1;
+    }
+
+    // wait for write to finish
+    while(_spi.write(0xFF) == 0);
+
+    _cs = 1; 
+    _spi.write(0xFF);
+    return 0;
+}
+
+static int ext_bits(char *data, int msb, int lsb) {
+    int bits = 0;
+    int size = 1 + msb - lsb; 
+    for(int i=0; i<size; i++) {
+        int position = lsb + i;
+        int byte = 15 - (position >> 3);
+        int bit = position & 0x7;
+        int value = (data[byte] >> bit) & 1;
+        bits |= value << i;
+    }
+    return bits;
+}
+
+int SDFileSystem::_sd_sectors() {
+
+    // CMD9, Response R2 (R1 byte + 16-byte block read)
+    if(_cmdx(9, 0) != 0) {
+        fprintf(stderr, "Didn't get a response from the disk\n");
+        return 0;
+    }
+    
+    char csd[16];    
+    if(_read(csd, 16) != 0) {
+        fprintf(stderr, "Couldn't read csd response from disk\n");
+        return 0;
+    }
+
+    // csd_structure : csd[127:126]
+    // c_size        : csd[73:62]
+    // c_size_mult   : csd[49:47]
+    // read_bl_len   : csd[83:80] - the *maximum* read block length
+
+    int csd_structure = ext_bits(csd, 127, 126);
+    int c_size = ext_bits(csd, 73, 62);
+    int c_size_mult = ext_bits(csd, 49, 47);
+    int read_bl_len = ext_bits(csd, 83, 80);
+
+//    printf("CSD_STRUCT = %d\n", csd_structure);
+    
+    if(csd_structure != 0) {
+        fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures\n");
+        return 0;
+    }
+             
+    // memory capacity = BLOCKNR * BLOCK_LEN
+    // where
+    //  BLOCKNR = (C_SIZE+1) * MULT
+    //  MULT = 2^(C_SIZE_MULT+2) (C_SIZE_MULT < 8)
+    //  BLOCK_LEN = 2^READ_BL_LEN, (READ_BL_LEN < 12)         
+                            
+    int block_len = 1 << read_bl_len;
+    int mult = 1 << (c_size_mult + 2);
+    int blocknr = (c_size + 1) * mult;
+    int capacity = blocknr * block_len;
+        
+    int blocks = capacity / 512;
+        
+    return blocks;
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SDFileSystem/SDFileSystem.h	Mon Dec 19 15:46:17 2011 +0000
@@ -0,0 +1,81 @@
+/* mbed SDFileSystem Library, for providing file access to SD cards
+ * Copyright (c) 2008-2010, sford
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MBED_SDFILESYSTEM_H
+#define MBED_SDFILESYSTEM_H
+
+#include "mbed.h"
+#include "FATFileSystem.h"
+
+/** Access the filesystem on an SD Card using SPI
+ *
+ * @code
+ * #include "mbed.h"
+ * #include "SDFileSystem.h"
+ *
+ * SDFileSystem sd(p5, p6, p7, p12, "sd"); // mosi, miso, sclk, cs
+ *  
+ * int main() {
+ *     FILE *fp = fopen("/sd/myfile.txt", "w");
+ *     fprintf(fp, "Hello World!\n");
+ *     fclose(fp);
+ * }
+ */
+class SDFileSystem : public FATFileSystem {
+public:
+
+    /** Create the File System for accessing an SD Card using SPI
+     *
+     * @param mosi SPI mosi pin connected to SD Card
+     * @param miso SPI miso pin conencted to SD Card
+     * @param sclk SPI sclk pin connected to SD Card
+     * @param cs   DigitalOut pin used as SD Card chip select
+     * @param name The name used to access the virtual filesystem
+     */
+    SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name);
+    virtual int disk_initialize();
+    virtual int disk_write(const char *buffer, int block_number);
+    virtual int disk_read(char *buffer, int block_number);    
+    virtual int disk_status();
+    virtual int disk_sync();
+    virtual int disk_sectors();
+
+protected:
+
+    int _cmd(int cmd, int arg);
+    int _cmdx(int cmd, int arg);
+    int _cmd8();
+    int _cmd58();
+    int initialise_card();
+    int initialise_card_v1();
+    int initialise_card_v2();
+    
+    int _read(char *buffer, int length);
+    int _write(const char *buffer, int length);
+    int _sd_sectors();
+    int _sectors;
+    
+    SPI _spi;
+    DigitalOut _cs;     
+};
+
+#endif

--- a/USBDevice/USBAudio/USBAudio.cpp	Fri Dec 16 17:12:56 2011 +0000
+++ b/USBDevice/USBAudio/USBAudio.cpp	Mon Dec 19 15:46:17 2011 +0000
@@ -24,12 +24,6 @@
 
 
 USBAudio::USBAudio(uint32_t frequency, uint8_t channel_nb, uint16_t vendor_id, uint16_t product_id, uint16_t product_release): USBDevice(vendor_id, product_id, product_release) {
-    mute = 0;
-    volCur = 0x0080;
-    volMin = 0x0000;
-    volMax = 0x0100;
-    volRes = 0x0004;
-    available = false;
 
     FREQ = frequency;
 
@@ -51,19 +45,6 @@
     USBDevice::connect();
 }
 
-bool USBAudio::read(uint8_t * buf) {
-    return true;
-}
-
-bool USBAudio::readNB(uint8_t * buf) {
-    return false;
-}
-
-
-float USBAudio::getVolume() {
-    return (mute) ? 0.0 : (float)volCur/(float)volMax;
-}
-
 bool USBAudio::write(uint8_t * buf) {
     readIN = false;
     SOF_handler = false;
@@ -80,7 +61,6 @@
     return true;
 }
 
-
 // Called in ISR context on each start of frame
 void USBAudio::SOF(int frameNumber) {
     if (buf_stream != NULL) {
@@ -125,28 +105,6 @@
 
 
 
-// Called in ISR context
-// Called by USBDevice on Endpoint0 request
-// This is used to handle extensions to standard requests and class specific requests.
-// Return true if class handles this request
-bool USBAudio::USBCallback_request() {
-    bool success = false;
-    CONTROL_TRANSFER * transfer = getTransferPtr();
-
-    // Process class-specific requests
-    if (transfer->setup.bmRequestType.Type == CLASS_TYPE) {
-        printf("class spe request\r\n");
-    }
-    return success;
-}
-
-
-// Called in ISR context when a data OUT stage has been performed
-void USBAudio::USBCallback_requestCompleted(uint8_t * buf, uint16_t length) {
-}
-
-
-
 #define TOTAL_DESCRIPTOR_LENGTH ((1 * CONFIGURATION_DESCRIPTOR_LENGTH) \
                                + (5 * INTERFACE_DESCRIPTOR_LENGTH) \
                                + (1 * CONTROL_INTERFACE_DESCRIPTOR_LENGTH) \

--- a/USBDevice/USBAudio/USBAudio.h	Fri Dec 16 17:12:56 2011 +0000
+++ b/USBDevice/USBAudio/USBAudio.h	Mon Dec 19 15:46:17 2011 +0000
@@ -78,54 +78,15 @@
     * @param product_release Your preoduct_release
     */
     USBAudio(uint32_t frequency = 48000, uint8_t channel_nb = 1, uint16_t vendor_id = 0x7bb8, uint16_t product_id = 0x1111, uint16_t product_release = 0x0100);
-
-    /**
-    * Get current volume between 0.0 and 1.0
-    *
-    * @returns volume
-    */
-    float getVolume();
     
-    /**
-    * Read an audio packet. warning: blocking
-    *
-    * @param buf pointer on a buffer which will be filled with an audio packet
-    *
-    * @returns true if successfull
-    */
-    bool read(uint8_t * buf);
     
     /**
-    * Try to read an audio packet. warning: non blocking
-    *
-    * @param buf pointer on a buffer which will be filled if an audio packet is available
+    * Write an audio packet
     *
-    * @returns true if successfull
+    * @param buf audio packet
+    * @returns true if successful
     */
-    bool readNB(uint8_t * buf);
-    
     bool write(uint8_t * buf);
-    
-
-    /** attach a handler to update the volume
-     *
-     * @param function Function to attach
-     *
-     */
-    void attach(void(*fptr)(void)) {
-        updateVol.attach(fptr);
-    }
-
-    /** Attach a nonstatic void/void member function to update the volume
-     *
-     * @param tptr Object pointer
-     * @param mptr Member function pointer
-     *
-     */
-    template<typename T>
-    void attach(T *tptr, void(T::*mptr)(void)) {
-        updateVol.attach(tptr, mptr);
-    }
 
 
 protected:
@@ -140,15 +101,6 @@
     virtual bool USBCallback_setConfiguration(uint8_t configuration);
 
     /*
-    * Called by USBDevice on Endpoint0 request. Warning: Called in ISR context
-    * This is used to handle extensions to standard requests
-    * and class specific requests
-    *
-    * @returns true if class handles this request
-    */
-    virtual bool USBCallback_request();
-
-    /*
     * Get string product descriptor
     *
     * @returns pointer to the string product descriptor
@@ -178,22 +130,15 @@
      */
     virtual bool USBCallback_setInterface(uint16_t interface, uint8_t alternate);
 
-    /*
-    * Called by USBDevice on Endpoint0 request completion
-    * if the 'notify' flag has been set to true. Warning: Called in ISR context
-    *
-    * In this case it is used to indicate that a HID report has
-    * been received from the host on endpoint 0
-    *
-    * @param buf buffer received on endpoint 0
-    * @param length length of this buffer
-    */
-    virtual void USBCallback_requestCompleted(uint8_t * buf, uint16_t length);
 
     /*
     * Callback called on each Start of Frame event
     */
     virtual void SOF(int frameNumber);
+    
+    /*
+    * Callback called when a packet has been sent
+    */
     virtual bool EP3_IN_callback();
 
 private:

--- a/USBDevice/USBDevice/USBBusInterface_LPC11U.cpp	Fri Dec 16 17:12:56 2011 +0000
+++ b/USBDevice/USBDevice/USBBusInterface_LPC11U.cpp	Mon Dec 19 15:46:17 2011 +0000
@@ -574,7 +574,6 @@
     instance->usbisr();
 }
 
-DigitalOut p(p20);
 void USBHAL::usbisr(void) {
     // Start of frame
     if (LPC_USB->INTSTAT & FRAME_INT) {
@@ -686,13 +685,11 @@
     }
 
     if (LPC_USB->INTSTAT & EP(EP3IN)) {
-        p = 1;
         // Clear EP3_IN interrupt
         LPC_USB->INTSTAT = EP(EP3IN);
         epComplete |= EP(EP3IN);
         if (EP3_IN_callback())
             epComplete &= ~EP(EP3IN);
-        p = 0;
     }
 
     if (LPC_USB->INTSTAT & EP(EP3OUT)) {

--- a/USBDevice/USBDevice/USBBusInterface_LPC17_LPC23.cpp	Fri Dec 16 17:12:56 2011 +0000
+++ b/USBDevice/USBDevice/USBBusInterface_LPC17_LPC23.cpp	Mon Dec 19 15:46:17 2011 +0000
@@ -520,7 +520,7 @@
     instance->usbisr();
 }
 
-DigitalOut p(p20);
+
 void USBHAL::usbisr(void) {
     uint8_t devStat;
 

--- a/main.cpp	Fri Dec 16 17:12:56 2011 +0000
+++ b/main.cpp	Mon Dec 19 15:46:17 2011 +0000
@@ -1,20 +1,50 @@
 #include "mbed.h"
 #include "USBAudio.h"
+#include "SDFileSystem.h"
 
 extern "C" void HardFault_Handler() {
     error("Hard Fault!\n");
 }
 
 USBAudio audio(8000, 1, 0x74ac, 0x8788);
+SDFileSystem sd(p5, p6, p7, p8, "sd"); // the pinout on the mbed Cool Components workshop board
+AnalogIn mic(p20);
+DigitalOut p(p21);
 
-//USBHID hid;
-uint16_t buf[8];
+/* Wav file header data, for setting up the transfer protocol */
+short channels;
+long sampleRate;
+short wordWidth;
+
+int16_t buf[8];
 
 int main() {
-    for (int i = 0; i < 8; i++) {
-        buf[i] = (i % 2) ? -255 : 255;
+    FILE * fp;
+
+    fp = fopen("/sd/3.wav", "r");
+    if (fp == NULL) {
+        error("Could not open file for write\n");
     }
+
+    printf("test\r\n");
+    /* Parse wav file header */
+    fseek(fp, 22, SEEK_SET);
+    fread(&channels, 2, 1, fp);
+    fseek(fp, 24, SEEK_SET);
+    fread(&sampleRate, 4, 1, fp);
+    fseek(fp, 34, SEEK_SET);
+    fread(&wordWidth, 2, 1, fp);
+
     while (1) {
+        p = 1;
+        for (int i = 0; i < 8; i++) {
+            if (!feof(fp)) {
+                fread(buf + i, 2, 1, fp);
+            } else {
+                fseek(fp, 36, SEEK_SET);
+            }
+        }
+        p = 0;
         audio.write((uint8_t *)buf);
     }
 }