Revision 0:82a02991476c, committed 2012-09-08

Comitter:

Xach

Date:

Sat Sep 08 20:40:58 2012 +0000

Commit message:

a program i made a while back to log gps/accelerometer data

Changed in this revision

diff -r 000000000000 -r 82a02991476c ACCEL_ADXL345.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ACCEL_ADXL345.cpp	Sat Sep 08 20:40:58 2012 +0000
@@ -0,0 +1,104 @@
+#include "ACCEL_ADXL345.h"
+#include "mbed.h"
+
+void accel_ISR() {
+    accelRdy = true;
+    accelTime = timer.read_us();
+    updateAccel();
+}
+
+void updateAccel() {
+  
+    __disable_irq();// if we are interrupted here i could mean we get accel data from 2 different samples
+    _cs = 0;
+    _spi.write(0xF2);   // Read X out reg and have it continue for 6 bytes
+    xraw0 =  _spi.write(0x0);
+    xraw1 =  _spi.write(0x0);
+    yraw0 =  _spi.write(0x0);
+    yraw1 =  _spi.write(0x0);
+    zraw0 =  _spi.write(0x0);
+    zraw1 =  _spi.write(0x0);
+    _cs = 1;
+    __enable_irq();
+    
+    //pc.printf(" X1=%i, X0=%i, Y1=%i, Y0=%i, Z1=%i, Z0=%i, \n",xraw1,xraw0,yraw1,yraw0,zraw1,zraw0);
+
+    //   pc.printf("%d %d %d",xaxis,yaxis,zaxis);
+}
+
+void convertAccel(){
+  xaxis = (float)(xraw0 | (xraw1 << 8))/250.0;//(((xraw1 & 0x01) | ((xraw1&0x01)<<3) )<< 8));
+  yaxis = (float)(yraw0 | (yraw1 << 8))/250.0;//(((yraw1 & 0x01) | ((yraw1&0x01)<<3) ) << 8));
+  zaxis = (float)(zraw0 | (zraw1 << 8))/250.0;//(((zraw1 & 0x01) | ((zraw1&0x01)<<3) ) << 8));
+
+}
+
+
+void initAccel() {
+
+    // Taken from datasheet
+    // 8 bit data
+    // High steady state clock
+    // Second edge capture
+    _spi.format(8,3);
+
+    // 5MHz clock rate
+    _spi.frequency(1000000);
+
+    // Select the device, active low chip select
+    _cs = 0;
+
+    _spi.write(0x31); // set data_format to 0b00000001 to turn on 4 wire mode with act high interrupts,10 bit mode and +- 4g operation
+    _spi.write(0x0B);
+    // end this transfer
+    _cs = 1;
+
+
+    wait (0.01); //this is stupid, get rid of it
+
+
+// new transfer
+    _cs = 0;
+
+    _spi.write(0x5D); // start writing at 0x1D but turn on sequential writes so we can set everything in one fowl swoop
+
+    _spi.write(0xFF);  // set THRESH_TAP - only used when corresponding interrupt is enabled
+    _spi.write(0x00); // set OFSX
+    _spi.write(0x00); // set OFSY
+    _spi.write(0x00); // set OFSZ
+    _spi.write(0xFF); // set DUR (min duration to be considered a TAP event)
+    _spi.write(0x00); // set Latent (max duration between TAP events)
+    _spi.write(0x00); // set Window (max time after a Latency to be in the same TAP window)
+    _spi.write(0x00); // set THRESH_ACT - only used when corresponding interrupt is enabled
+    _spi.write(0x00); // set THRESH_INACT - only used when corresponding interrupt is enabled
+    _spi.write(0xFF); // set TIME_INACT - only used when corresponding interrupt is enabled
+    _spi.write(0x00); // set ACT_INACT_CTL - AC/DC coupling for activity registers + enabling/disabling in x,y.z - only used when corresponding interrupt is enabled
+    _spi.write(0xFF); // set THRESH_FF (free fall) - only used when corresponding interrupt is enabled
+    _spi.write(0xFF); // set TIME_FF (free fall)
+    _spi.write(0x00); // set TAP_AXES (with 0x00 we are disabling all tap detection)
+    // end this transfer
+    _cs = 1;
+
+// start another multiple byte transfer
+    _cs = 0;
+    _spi.write(0x6C); // another sequential write starting at 0x2C
+    _spi.write(0x0E); // set BW_RATE to disable low power and turn on max bandwidth
+    _spi.write(0x0B); // set // set PWR_CTRL to start measurments, and not be asleep , and to do 8hz measurements if asleep
+    _spi.write(0x00); // set INT_ENABLE
+    _spi.write(0x00); // set INT_MAP - send all interrupts to INT1 but doesnt really matter because we wont use this (yet)
+    _cs = 1;
+
+    // start new transfer
+    _cs = 0;
+    _spi.write(0x38); // FIFO_CTL
+    _spi.write(0x00); // disable the FIFO
+    _cs = 1;
+
+    _cs = 0;
+    _spi.write(0x80);
+    wait(.1);
+    devid = _spi.write(0x0);
+    _cs  = 1;
+    accel.attach_us(&accel_ISR, 625);
+    accelRdy = false;
+}

diff -r 000000000000 -r 82a02991476c ACCEL_ADXL345.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ACCEL_ADXL345.h	Sat Sep 08 20:40:58 2012 +0000
@@ -0,0 +1,19 @@
+
+#include"mbed.h"
+
+SPI _spi (p5,p6,p7);
+DigitalOut _cs (p8);
+
+void updateAccel();
+void convertAccel();
+void initAccel();
+void accel_ISR();
+volatile bool accelRdy;
+volatile int accelTime;
+unsigned char xraw0, yraw0, zraw0;
+signed char xraw1, yraw1, zraw1;
+float xaxis, yaxis,zaxis;
+unsigned char devid;
+Ticker accel;
+
+Timer timer;

diff -r 000000000000 -r 82a02991476c FATFileSystem.lib
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/FATFileSystem.lib	Sat Sep 08 20:40:58 2012 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_unsupported/code/FatFileSystem/#333d6e93e58f

diff -r 000000000000 -r 82a02991476c GPS_LS20031.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/GPS_LS20031.cpp	Sat Sep 08 20:40:58 2012 +0000
@@ -0,0 +1,49 @@
+
+#include "GPS_LS20031.h"
+#include "mbed.h"
+
+
+
+char checkSum(char* theseChars) {
+    char check = 0;
+    // iterate over the string, XOR each byte with the total sum:
+
+    for (int c = 1;theseChars[c]!= '*'; c++) {
+        check = char(check ^ theseChars[c]);
+    }
+    // return the result
+    return check;
+}
+
+bool NMEA_parse(char *msg) {
+    char ns, ew,av;
+    float magVar;
+
+
+    // Check if it is a GPGGA msg (matches both locked and non-locked msg)
+    if (sscanf(msg, "$GPRMC,%f,%c,%f,%c,%f,%c,%f,%f,%f", &timeG, &av, &latitude, &ns, &longitude, &ew, &speed_knotts, &magVar, &date) >= 1) {
+        if (av == 'A') {
+            if (ns == 'S') {
+                latitude  *= -1.0;
+            }
+            if (ew == 'W') {
+                longitude *= -1.0;
+            }
+            return true;
+            /*  float degrees = trunc(latitude / 100.0f);
+              float minutes = latitude - (degrees * 100.0f);
+              latitude = degrees + minutes / 60.0f;
+              degrees = trunc(longitude / 100.0f);  //a term had to be removed from this line
+              minutes = longitude - (degrees * 100.0f);
+              longitude = degrees + minutes / 60.0f;*/
+        }
+         else {
+            longitude = 0.0;
+            latitude = 0.0;
+            return false;
+        }
+
+    }
+    return false;
+
+}
\ No newline at end of file

diff -r 000000000000 -r 82a02991476c GPS_LS20031.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/GPS_LS20031.h	Sat Sep 08 20:40:58 2012 +0000
@@ -0,0 +1,13 @@
+#pragma once
+#ifndef GPS_LS20031_H
+#define GPS_LS20031_H
+
+bool NMEA_parse(char* msg);
+char checkSum(char* theseChars);
+float date;
+float latitude;
+float longitude;
+float speed_knotts;
+float timeG;
+
+#endif
\ No newline at end of file

diff -r 000000000000 -r 82a02991476c SDFileSystem.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SDFileSystem.cpp	Sat Sep 08 20:40:58 2012 +0000
@@ -0,0 +1,295 @@
+/* mbed Microcontroller Library - SDFileSystem
+ * Copyright (c) 2008-2009, sford
+ *
+ * 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; 
+}
+
+int SDFileSystem::disk_initialize() {
+
+    _spi.frequency(100000); // Set to 100kHz for initialisation
+    
+    // Initialise the card by clocking it a bit (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) != 0x01) { 
+        fprintf(stderr, "Not in idle state\n");
+        fprintf(stderr, "_cnd value = %i\n", _cmd(0,0));
+        return 1;
+    }
+    
+    // ACMD41 to give host capacity support (repeat until not busy)
+    // ACMD41 is application specific command, so we send APP_CMD (CMD55) beforehand
+    for(int i=0;; i++) {
+        _cmd(55, 0); 
+        int response = _cmd(41, 0);
+        if(response == 0) { 
+            break;
+        } else if(i > SD_COMMAND_TIMEOUT) {
+            fprintf(stderr, "Timeout waiting for card\n");
+            return 1;
+        }    
+    }
+
+    _sectors = _sd_sectors();
+
+    // Set block length to 512 (CMD16)
+    if(_cmd(16, 512) != 0) {
+        fprintf(stderr, "Set block timeout\n");
+        return 1;
+    }
+        
+    _spi.frequency(5000000); // 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;
+            return response;
+        }
+    }
+    _cs = 1;
+    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;    
+    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; 
+        return 1;
+    }
+
+    // wait for write to finish
+    while(_spi.write(0xFF) == 0);
+
+    _cs = 1; 
+    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(_cmd(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] 
+
+    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);
+    
+    if(csd_structure != 0) {
+        fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures");
+        return 0;
+    }
+                            
+    int blocks = (c_size + 1) * (1 << (c_size_mult + 2));
+    int block_size = 1 << read_bl_len;
+
+    if(block_size != 512) {
+        fprintf(stderr, "This disk tastes funny! I only like 512-byte blocks");
+        return 0;
+    }
+    
+    return blocks;
+}

diff -r 000000000000 -r 82a02991476c SDFileSystem.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SDFileSystem.h	Sat Sep 08 20:40:58 2012 +0000
@@ -0,0 +1,56 @@
+/* mbed Microcontroller Library - SDFileSystem
+ * Copyright (c) 2008-2009, sford
+ */
+
+#ifndef SDFILESYSTEM_H
+#define SDFILESYSTEM_H
+
+#include "mbed.h"
+#include "FATFileSystem.h"
+
+/* Class: SDFileSystem
+ *  Access the filesystem on an SD Card using SPI
+ *
+ * Example:
+ * > SDFileSystem sd(p5, p6, p7, p12, "sd");
+ * > 
+ * > int main() {
+ * >     FILE *fp = fopen("/sd/myfile.txt", "w");
+ * >     fprintf(fp, "Hello World!\n");
+ * >     fclose(fp);
+ * > }
+ */
+class SDFileSystem : public FATFileSystem {
+public:
+
+	/* Constructor: SDFileSystem
+	 *  Create the File System for accessing an SD Card using SPI
+	 *
+	 * Variables:
+	 *  mosi - SPI mosi pin connected to SD Card
+	 *  miso - SPI miso pin conencted to SD Card
+	 *  sclk - SPI sclk pin connected to SD Card
+	 *  cs   - DigitalOut pin used as SD Card chip select
+   *  name - The name used to access the 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 _read(char *buffer, int length);
+	int _write(const char *buffer, int length);
+	int _sd_sectors();
+	int _sectors;
+	
+	SPI _spi;
+	DigitalOut _cs;	 
+};
+
+#endif

diff -r 000000000000 -r 82a02991476c SerialBuffered.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SerialBuffered.cpp	Sat Sep 08 20:40:58 2012 +0000
@@ -0,0 +1,155 @@
+
+#include "mbed.h"
+#include "SerialBuffered.h"
+#include <string.h>
+
+//extern Serial loggerSerial;
+
+SerialBuffered::SerialBuffered( size_t bufferSize, PinName tx, PinName rx ) : Serial(  tx,  rx ) {
+    m_buffSize = 0;
+    m_contentStart = 0;
+    m_contentEnd = 0;
+    m_timeout = 1.0;
+    ReadStrings = false;
+    unreadStrings = 0;
+
+    attach( this, &SerialBuffered::handleInterrupt );
+
+    m_buff = (uint8_t *) malloc( bufferSize );
+    if ( m_buff == NULL ) {
+        //loggerSerial.printf("SerialBuffered - failed to alloc buffer size %d\r\n", (int) bufferSize );
+    } else {
+        m_buffSize = bufferSize;
+    }
+}
+
+
+SerialBuffered::~SerialBuffered() {
+    if ( m_buff )
+        free( m_buff );
+    if (str_buff);
+    free(str_buff);
+}
+
+
+void SerialBuffered::setTimeout( float seconds ) {
+    m_timeout = seconds;
+}
+////////////////////
+void SerialBuffered::startReadStrings( char endChar) {
+    term = endChar;
+    str_buff_pos = 0;
+    str_wr_buff_pos = 0;
+    int i;
+    for (i = 0; i < STRING_BUFFERS; i++)
+        str_buff[i] = (char *) malloc(m_buffSize);
+
+    ReadStrings = true;
+}
+
+void SerialBuffered::stopReadStrings() {
+    ReadStrings = false;
+
+}
+
+int SerialBuffered::stringsAvailable() {
+    if (unreadStrings < STRING_BUFFERS)
+        return unreadStrings;
+    else
+        return -1;
+}
+
+char* SerialBuffered::getString() {
+    unreadStrings--;
+    if (str_buff_pos >= STRING_BUFFERS)
+        str_buff_pos = 0;
+
+    return str_buff[str_buff_pos++];
+}
+//////////////////////////////////////////
+
+size_t SerialBuffered::readBytes( uint8_t *bytes, size_t requested ) {
+    int i = 0;
+
+    for ( ; i < requested; ) {
+        int c = getc();
+        if ( c < 0 )
+            break;
+        bytes[i] = c;
+        i++;
+    }
+
+    return i;
+
+}
+
+
+
+
+
+int SerialBuffered::getc() {
+    m_timer.reset();
+    m_timer.start();
+    while ( m_contentStart == m_contentEnd ) {
+
+
+        wait_ms( 1 );
+        if ( m_timeout > 0 &&  m_timer.read() > m_timeout )
+            return EOF;
+    }
+
+    m_timer.stop();
+
+    uint8_t result = m_buff[m_contentStart++];
+    m_contentStart =  m_contentStart % m_buffSize;
+
+
+    return result;
+}
+
+
+int SerialBuffered::readable() {
+    return m_contentStart != m_contentEnd ;
+}
+
+
+
+
+//isr
+void SerialBuffered::handleInterrupt() {
+    if (ReadStrings) {
+
+        str_buff[str_wr_buff_pos][ m_contentEnd ] = Serial::getc();
+        if (str_buff[str_wr_buff_pos][ m_contentEnd ] == term) {
+            str_buff[str_wr_buff_pos][ m_contentEnd + 1 ] = '\0';
+            unreadStrings++;
+            str_wr_buff_pos++;
+            m_contentEnd = 0;
+            
+            if (str_wr_buff_pos >= STRING_BUFFERS)
+                str_wr_buff_pos = 0;
+            if (unreadStrings >= STRING_BUFFERS)
+                unreadStrings = 0;
+        } else {
+            m_contentEnd = ++m_contentEnd % m_buffSize;
+        }
+
+
+    } else {
+        while ( Serial::readable()) {
+            if ( m_contentStart == (m_contentEnd +1) % m_buffSize) {
+                //         loggerSerial.printf("SerialBuffered - buffer overrun, data lost!\r\n" );
+                Serial::getc();
+
+            } else {
+
+                m_buff[ m_contentEnd ++ ] = Serial::getc();
+                m_contentEnd = m_contentEnd % m_buffSize;
+
+
+
+            }
+        }
+    }
+}
+

diff -r 000000000000 -r 82a02991476c SerialBuffered.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SerialBuffered.h	Sat Sep 08 20:40:58 2012 +0000
@@ -0,0 +1,52 @@
+#pragma once
+
+// This is a buffered serial reading class, using the serial interrupt introduced in mbed library version 18 on 17/11/09
+
+// In the simplest case, construct it with a buffer size at least equal to the largest message you
+// expect your program to receive in one go.
+#define STRING_BUFFERS 24
+
+class SerialBuffered : public Serial {
+public:
+    SerialBuffered( size_t bufferSize, PinName tx, PinName rx );
+    virtual ~SerialBuffered();
+
+    int getc();     // will block till the next character turns up, or return -1 if there is a timeout
+
+    int readable(); // returns 1 if there is a character available to read, 0 otherwise
+
+    int strReady(); // returns the number of strings ready
+
+
+
+
+    void setTimeout( float seconds );    // maximum time in seconds that getc() should block
+    // while waiting for a character
+    // Pass -1 to disable the timeout.
+
+    size_t readBytes( uint8_t *bytes, size_t requested );    // read requested bytes into a buffer,
+    // return number actually read,
+    // which may be less than requested if there has been a timeout
+    
+    void startReadStrings( char term);
+    void stopReadStrings();
+    char* getString();
+    int stringsAvailable();
+private:
+
+    void handleInterrupt();
+
+
+    uint8_t *m_buff;            // points at a circular buffer, containing data from m_contentStart, for m_contentSize bytes, wrapping when you get to the end
+    uint16_t  m_contentStart;   // index of first bytes of content
+    uint16_t  m_contentEnd;     // index of bytes after last byte of content
+    uint16_t m_buffSize;
+    float m_timeout;
+    Timer m_timer;
+    int unreadStrings;
+    char term;
+    bool ReadStrings;
+    char *str_buff[STRING_BUFFERS];
+    int str_buff_pos;
+    int str_wr_buff_pos;
+};
\ No newline at end of file

diff -r 000000000000 -r 82a02991476c globals.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/globals.h	Sat Sep 08 20:40:58 2012 +0000
@@ -0,0 +1,25 @@
+#ifndef GLOBALS_H // header guards
+#define GLOBALS_H
+
+extern void updateAccel();
+extern void initAccel();
+extern void convertAccel();
+extern Timer timer;
+
+extern unsigned char xraw0, yraw0, zraw0;
+extern signed char xraw1, yraw1, zraw1;
+extern float xaxis, yaxis,zaxis;
+extern unsigned char devid;
+extern volatile bool accelRdy;
+extern volatile int accelTime;
+
+extern bool NMEA_parse(char* msg);
+extern char checkSum(char* theseChars);
+extern float date;
+extern float latitude;
+extern float longitude;
+extern float speed_knotts;
+extern float timeG;
+
+
+#endif

diff -r 000000000000 -r 82a02991476c main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sat Sep 08 20:40:58 2012 +0000
@@ -0,0 +1,188 @@
+#include "mbed.h"
+#include "SerialBuffered.h"
+#include "globals.h"
+#include "SDFileSystem.h"
+#include "string.h"
+
+#define SDWrite(STR) ((fp == NULL) ? fprintf(fp, STR) : errorled=1)
+
+PwmOut Red(p25);
+PwmOut Green(p23);
+PwmOut Blue(p21);
+
+
+SDFileSystem sd(p11, p12, p13, p10, "sd");
+DigitalOut myled(LED1);
+DigitalOut genled(LED2);
+DigitalOut errorled(LED3);
+DigitalOut successled(LED4);
+Serial pc (USBTX,USBRX);
+//FILE *fp = fopen("/sd/foo.txt", "w");
+
+
+
+
+int main() {
+    Red.period_us(100);
+    Green.period_us(100);
+    Blue.period_us(100);
+    Red = 0;
+    Green = 0;
+    Blue = 0;
+
+    int flushCount = 0;
+    int fileStartTime = 0;
+
+    errorled = 0;
+    initAccel();
+
+    while (devid == 0) {
+        initAccel();
+        pc.printf("devid=%u\n",devid);
+    }
+    pc.printf("devid=%u\n",devid);
+    fp = fopen("/sd/clbr.txt", "a");
+    int j = 0;
+    while (j<6400) {
+        if (accelRdy) {
+            accelRdy = false;
+
+            convertAccel;
+            j++;
+        }
+    }
+    pc.printf("NMEA data from LS20031:\n");
+    char * pva_sent = (char *)calloc(255, sizeof(char));
+    char * titlePath = (char *)calloc(255, sizeof(char));
+
+    SerialBuffered *b = new SerialBuffered( 256, p28, p27);
+    b->baud( 56000 );
+    //only need to do this once to set up rmc
+    //   char setup[] = "$PMTK314,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*%x\r\n";
+    // pc.printf("checksum : %x", checkSum(setup));
+    // b->printf(setup, checkSum(setup));
+
+    b->startReadStrings('\n');
+    b->setTimeout( 0.1 );//stupid , shouldnt need this
+    char* line[32];
+
+    myled = 1;
+    genled = 1;
+
+    while (b->stringsAvailable()<=0); // we need to wait for gps string
+    char * firstMsg = b->getString();
+    while (!NMEA_parse(firstMsg)) {
+
+        if (b->stringsAvailable()>0)
+            firstMsg = b->getString();
+    }
+    while (b->stringsAvailable()>0) {
+        firstMsg = b->getString();
+        NMEA_parse(firstMsg);
+    }
+
+    myled = 0;
+    genled = 0;
+
+    fileStartTime = (int)timeG/10000;
+    sprintf (titlePath, "/sd/%i_%i.txt",(int)date/10000 , (int)timeG/10000);
+    pc.printf(titlePath);
+    FILE *fp = fopen(titlePath, "a");
+
+    while (fp == NULL) {
+        wait (1);
+        errorled = 1;
+        successled = 1;
+        genled = 1;
+        myled = 1;
+        wait(1);
+        errorled = 0;
+        successled = 0;
+        genled = 0;
+        myled = 0;
+        if (b->stringsAvailable()>0) {
+            firstMsg = b->getString();
+            NMEA_parse(firstMsg);
+        }
+        fileStartTime = (int)timeG/10000;
+        sprintf (titlePath, "/sd/%i_%i.txt",(int)date/10000 , (int)timeG/10000);
+        fp = fopen(titlePath, "a");
+    }
+
+    pc.printf(titlePath);
+    fprintf(fp,"break,\n");
+
+    timer.start();
+    while (1) {
+        if (accelRdy) {
+            accelRdy = false;
+            convertAccel();
+            sprintf (pva_sent,"A,%i,%f,%f,%f\n",accelTime,xaxis,yaxis,zaxis);
+            // sprintf (pva_sent,"%f,%f,%f\n", xaxis,yaxis,zaxis);
+            // pc.printf(pva_sent);
+            fprintf(fp,pva_sent);
+            Red = abs(yaxis);
+            Blue = abs(zaxis);
+            Green = abs(xaxis);
+            successled = 1;
+        }
+
+        int i= 0;
+        while (b->stringsAvailable()>0) {
+            updateAccel();
+            timer.reset();
+            if (i<STRING_BUFFERS)
+                line[i++] = b->getString();
+            else
+                break;
+        }
+
+        //    pc.printf("\n\navailable:%i\n", i); //if i>1 it would be a good idea to throw an error
+
+        while (i>=1) {
+            flushCount++;
+            if (flushCount > 150) {
+
+                flushCount = 0;
+                fclose(fp);
+
+                if (fileStartTime - (int)timeG/10000 != 0) {
+                    fileStartTime = (int)timeG/10000;
+                    if (date != 0)
+                        sprintf (titlePath, "/sd/%i_%i.txt",(int)date/10000 , (int)timeG/10000);
+                }
+                fp = fopen(titlePath, "a");
+                while (fp == NULL) {
+                    wait (1);
+                    errorled = 1;
+                    successled = 1;
+                    genled = 1;
+                    myled = 1;
+                    wait(1);
+                    errorled = 0;
+                    successled = 0;
+                    genled = 0;
+                    myled = 0;
+
+                    fp = fopen(titlePath, "a");
+                }
+
+            }
+            NMEA_parse(line[--i]);
+
+            //sprintf (pva_sent,"\ngot line:%i\nDate:%f Time:%f Lat:%f Lon:%f Speed:%f Ax:%f Ay:%f Az:%f", i ,date,timeG,latitude,longitude,speed_knotts,xaxis,yaxis,zaxis);
+            sprintf (pva_sent,"G,%i,%f,%f,%f,%f,%f,%f,%f\n",(int)date,timeG,latitude,longitude,speed_knotts,xaxis,yaxis,zaxis);
+            //  pc.printf(pva_sent);
+            successled = 1;
+            fprintf(fp,pva_sent);
+            successled = 0;
+            //pc.printf("A X=%f, Y=%f, Z=%f\n",xaxis,yaxis,zaxis);
+
+        }
+
+
+    }
+}
+
+
+

diff -r 000000000000 -r 82a02991476c mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Sat Sep 08 20:40:58 2012 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/49a220cc26e0
\ No newline at end of file