Revision 0:aaddc17011a9, committed 2012-03-08

Comitter:

xherpe

Date:

Thu Mar 08 16:32:35 2012 +0000

Commit message:

Changed in this revision

diff -r 000000000000 -r aaddc17011a9 FATFileSystem.lib
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/FATFileSystem.lib	Thu Mar 08 16:32:35 2012 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_unsupported/code/fatfilesystem/
\ No newline at end of file

diff -r 000000000000 -r aaddc17011a9 MCP23017.lib
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MCP23017.lib	Thu Mar 08 16:32:35 2012 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/jimherd/code/MCP23017/#d57de266cf19

diff -r 000000000000 -r aaddc17011a9 SDFileSystem.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SDFileSystem.cpp	Thu Mar 08 16:32:35 2012 +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;
+}

diff -r 000000000000 -r aaddc17011a9 SDFileSystem.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SDFileSystem.h	Thu Mar 08 16:32:35 2012 +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

diff -r 000000000000 -r aaddc17011a9 WattBob_TextLCD.lib
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WattBob_TextLCD.lib	Thu Mar 08 16:32:35 2012 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/jimherd/code/WattBob_TextLCD/#020722c18a8b

diff -r 000000000000 -r aaddc17011a9 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Mar 08 16:32:35 2012 +0000
@@ -0,0 +1,429 @@
+// XAVIER HERPE                                      Assignment 2
+// 5th year Robotics & Cybertronics
+// Heriot-Watt University
+
+#include "mbed.h"
+#include "MCP23017.h"
+#include "WattBob_TextLCD.h"
+#include "SDFileSystem.h"
+#include "FATFileSystem.h"
+
+#define     BACK_LIGHT_ON(INTERFACE)    INTERFACE->write_bit(1,BL_BIT)
+#define     BACK_LIGHT_OFF(INTERFACE)    INTERFACE->write_bit(0,BL_BIT)
+
+// Pointers to LCD screen and SD card
+MCP23017            *par_port;  // pointer to 16-bit parallel I/O chip
+WattBob_TextLCD     *lcd;       // pointer to 2*16 character LCD object
+FILE                *fp;        // Pointer to SD card object
+
+
+//=====================================================================================
+//  I/O ports allocation
+//=====================================================================================
+DigitalIn TTL(p17); // TTL input for frequency measurement
+DigitalIn switch_1(p18); // Switch 1 input
+DigitalIn switch_2(p19); // Switch 2 input
+DigitalIn switch_off(p11); // Switch used to close SD file and stop cyclic executive
+AnalogIn analogue_in_1(p15); // POT value
+AnalogIn analogue_in_2(p16); // LDR value
+PwmOut servo(p21); // Servo output
+DigitalOut TestPin(p20); // Pin only used to test program and measure time
+SDFileSystem sd(p5, p6, p7, p8, "sd"); // The pinout on the mbed Cool Components workshop board
+
+
+//=====================================================================================
+// Internal objects declaration
+// ====================================================================================
+BusOut LEDs(LED4, LED3, LED2, LED1); // Address the four LEDs to a single bus
+Timer timer; // Timer used to measure frequency in task 1
+Timer DoNothing; // Timer used to measure how long the program does nothing
+Ticker ticker; // Ticker used as clock for cyclic executive program
+
+
+//=====================================================================================
+// Constants declaration
+//=====================================================================================
+const int SampFreq = 100; // Sampling frequency is 10kHz (100us)
+
+
+//=====================================================================================
+// Variables declaration
+//=====================================================================================
+
+// Variables for cyclic executive program
+long int ticks = 0; // Used to define what task to call in the cyclic executive program
+int NoTask = 0; // Used to return how long the program does nothing in ms
+int NoTaskCount = 0; // Variable incremented until one total cycle of 10 seconds is reached
+
+// Variables for tasks 1 and 2
+int period = 0; // Returned period of the TTL input signal
+int frequency = 0; // Returned frequency of the TTL signal
+
+// Varibles for task 4
+int switch_1_val = 0; // Used to return how many times the switch is high
+int switch_2_val = 0;
+bool switch_1_state = 0; // Used to define whether the debounced switch is ON or OFF
+bool switch_2_state = 0;
+
+// Variables for task 5
+float analogue_1_val = 0; // Used to return the filtered analogue input
+float analogue_2_val = 0;
+
+int analogue_1_int = 0; // Used to convert float to int (results in quicker display on LCD in task 6)
+int analogue_2_int = 0;
+
+// Variable for task 7
+int LogCount = 0; // Used to define logging number
+
+// Variable used for task 8
+int BinCount = 0; // Used to increment a binary display on LEDs. Goes from 0 to 15 and then is reset
+bool BinEnable = 0; // Used to tell task 5 to display binary pattern on LEDs every 1.5s
+int IncCheck = 0; // Check increment to see if 6 cycles have elapsed to light LEDs ( 6 * 250us = 1.5s)
+
+
+//=====================================================================================
+// Task declaration
+//=====================================================================================
+
+void CyclEx();
+
+void Task1(); // Measure TTL input frequency
+void Task2(); // Show frequency on LCD screen
+void Task3(); // Show speed on servo dial
+void Task4(); // Read and debounce two digital inputs
+void Task5(); // Read and filter two analogue inputs
+void Task6(); // Display digital and analogue inputs on LCD screen
+void Task7(); // Log speed, analogue and digital inputs on SD card
+void Task8(); // Display error message on LCD screen and display binary pattern on LEDs
+
+void WaitRisEdge(); // Subroutine to detect rising edge
+void WaitFalEdge(); // Subroutine to detect falling edge
+
+void Stop(); // Close log file and stop cyclic executive
+
+
+//=====================================================================================
+// Main program
+//=====================================================================================
+
+int main()
+{
+
+    // LCD Screen Initialisation
+    par_port = new MCP23017(p9, p10, 0x40); // initialise 16-bit I/O chip
+    lcd = new WattBob_TextLCD(par_port); // initialise 2*26 char display
+    par_port->write_bit(1,BL_BIT); // turn LCD backlight ON
+    lcd->cls(); // clear display
+
+    // EXEL log file initialisation
+    fp = fopen("/sd/log.xls", "w"); // pointer to log in text file called "log". (Use "a" to not delete file)
+    fprintf(fp, "This file is the property of Xavier Herpe, the French\n\n");
+
+    // DoNothing timer reset
+    DoNothing.reset();
+    
+    // Internal ticker set to 25ms. Every 25ms, the scheduler is called and selects the task to run
+    ticker.attach(&CyclEx, 0.025); // Period set to 25ms
+    while(1)// Run until system shuts down
+    {
+         
+    } 
+}
+
+// Where tasks are scheduled based on an EXEL sheet
+void CyclEx()
+{   
+    // Stop timer when a new task starts 
+    DoNothing.stop();
+    
+    if(ticks % 80 == 4) // Occures every 80 clock cycles (2 seconds). Starts with an offset of 4 clock cycles
+    {
+        Task1(); 
+    }    
+
+    else if(ticks % 200 == 8) // Occures every 200 clock cycles (5 seconds). Starts with an offset of 8 clock cycles
+    {       
+        Task2();      
+    }
+    else if(ticks % 240 == 7) // Occures every 240 clock cycles (6 seconds). Starts with an offset of 7 clock cycles
+    {
+        Task3();    
+    }
+    else if(ticks % 4 == 0) // Occures every 4 clock cycles (0.1 seconds). Starts with an offset of 0 clock cycles
+    {
+        Task4(); 
+    }
+    else if(ticks % 10 == 1) // Occures every 10 clock cycles (0.25 seconds). Starts with an offset of 1 clock cycles
+    {   
+        Task5(); 
+    }
+    else if(ticks % 40 == 3) // Occures every 40 clock cycles (1 seconds). Starts with an offset of 3 clock cycles
+    {
+        Task6(); 
+    }
+    else if(ticks % 400 == 10) // Occures every 400 clock cycles (10 seconds). Starts with an offset of 10 clock cycles
+    {
+        Task7(); 
+    }
+    else if(ticks % 160 == 6) // Occures every 160 clock cycles (4 seconds). Starts with an offset of 6 clock cycles
+    {  
+        Task8(); 
+    }
+    
+    if (switch_off == 1) // Pin used to log data on SD card and stop Cyclic executive program
+         {
+             Stop();
+         }
+    ticks++;
+    
+    // Start timer when one task is ended 
+    DoNothing.start();
+    NoTaskCount++;
+    
+    // When one full cycle of 10 seconds is finished, return how long the program was doing nothing (lazy program)
+    if (NoTaskCount == 400)
+    {
+        NoTask = DoNothing.read_ms();
+        NoTaskCount = 0;
+        DoNothing.reset();
+    }
+}
+
+
+//=====================================================================================
+// Tasks
+//=====================================================================================
+
+// Task 1: Measure TTL input frequency
+void Task1()
+{
+    timer.reset();
+    
+    // If the input signal is low, wait for a rising edge to start counting
+    if (TTL == 0)
+    {
+        WaitRisEdge(); // Call subroutine to wait for rising edge
+        timer.start(); // Start timer
+        while(TTL == 1) // Keep counting as long as signal is high
+        {
+            wait_us(SampFreq);
+        }
+    }
+    
+    // If the input signal is high, wait for a falling edge to start counting
+    else if (TTL == 1)
+    {
+        WaitFalEdge(); // Call subroutine to wait for falling edge
+        timer.start(); // Start timer
+        while(TTL == 0) // Keep counting as long as signal is high
+        {
+            wait_us(SampFreq);
+        }
+    }
+
+    timer.stop(); // Stop counting when signal changes
+    period = timer.read_us()*2; // Convert the time into a period
+    frequency = 1000000/period; // Convert the period into a frequency
+}
+
+
+
+// Task 2: display the measured frequency on LCD screen
+void Task2()
+{
+    lcd->cls(); // clear display
+    lcd->locate(0,0); // set cursor to location (0,0) - top left corner
+    lcd->printf("%d Hz",frequency); // print the frequency calculated in task 1
+}
+
+
+
+// Task 3: show speed on servo output dial
+void Task3()
+{
+    servo.period(0.02); // servo requires a 20ms period
+    // To rotate the servo from -90 to +90 degrees, the pulse width must varies between 600us to 2300us
+    // The pulse width is calculated from the speed measured in task one
+    // 50Hz is equivalent to -90 degrees and 100Hz is equivalent to 90 degrees
+    // 1Hz change is equal to 34us pulse width change, so pulse width = ((frequency - 50)*34) + 600
+    servo.pulsewidth_us(2300-((frequency - 50)*34));
+    wait_ms(1); // Leave the servo some time to reach its position
+}
+
+
+
+// Task 4: Read two digital inputs (debounced)
+void Task4()
+{
+    switch_1_val = 0;
+    switch_2_val = 0;
+
+    // Read each switch three consecutive times with 100us between readings
+    for(int i=0; i<3; i++)
+    {
+        if (switch_1 == 1) // Increment variable if switch 1 is pressed
+        {
+            switch_1_val++;
+        }
+
+        if (switch_2 == 1) // Increment variable if switch 2 is pressed
+        {
+            switch_2_val++;
+        }
+
+        wait_us(SampFreq);
+    }
+    // Check how many times switch 1 has been high
+    // if it has been high more than twice, then switch 1 state = 1
+    if (switch_1_val > 1)
+    {
+        switch_1_state = 1;
+    }
+    else
+    {
+        switch_1_state = 0;
+    }
+
+    // Check how many times switch 1 has been high
+    // if it has been high more than twice, then switch 2 state = 1
+    if (switch_2_val > 1)
+    {
+        switch_2_state = 1;
+    }
+
+    else
+    {
+        switch_2_state = 0;
+    }
+}
+
+
+
+// Task 5: Read two analogue inputs (filtered)
+void Task5()
+{
+    analogue_1_val = 0; // Reset variables
+    analogue_2_val = 0;
+
+    // Takes four readings of each analogue input. Readings occure every 0.1ms
+    // Because the analogue.read() function returns a value from 0 to 1,
+    // we need to multiply the readings by 3.3 to cover 0V to 3.3V
+    for(int i=0; i<4;i++)
+    {
+        analogue_1_val = analogue_1_val + (analogue_in_1*3.3);
+        analogue_2_val = analogue_2_val + (analogue_in_2*3.3);
+        wait_us(SampFreq);
+    }
+
+    analogue_1_val = (analogue_1_val / 4);
+    analogue_2_val = (analogue_2_val / 4);
+    
+    analogue_1_int = analogue_1_val * 10; // Convert floating point into an integer to reduce display delay
+    analogue_2_int = analogue_2_val * 10;
+    
+    // This section of task 5 is used to take over part of task 8.
+    // Since the LEDs pattern has to be incremented every 1.5s, the pattern is
+    // incremented every 6 cycles, which correspond to 1.5s.
+    if(BinEnable == 1)
+    {
+        IncCheck++; 
+        
+        if(IncCheck == 6) // Corresponds to 1.5s. Increment binary pattern
+        {
+            LEDs = BinCount;
+            BinCount++;
+            IncCheck = 0;
+
+            if (BinCount > 15) // Used to reset variable once maximum 4-bit binary value is reached
+            {
+                BinCount = 0;
+            }  
+        }  
+    }
+}
+
+
+
+// Task 6: Display analogue and digital values on LCD screen
+void Task6()
+{
+   // lcd->cls(); // clear display (takes too long)
+    lcd->locate(0,0); // set cursor to location (0,0) - top left corner
+    lcd->printf("%d %d%d%d",analogue_1_int,analogue_2_int,switch_1_state,switch_2_state);
+}
+
+
+
+// Task 7: Log values on SD card
+void Task7()
+{    
+     LogCount++; //Used to print the logging number in file. Starts from 1
+     fprintf(fp, "Log:  %d,   Speed: %dHz,   Switch_1: %d,   Switch_2: %d,   POT: %.2fVolts,   LDR: %.2fVolts\n",LogCount,frequency,switch_1_state,switch_2_state,analogue_1_val,analogue_2_val);
+}
+
+
+
+// Task 8: Show error message and light LEDs
+void Task8()
+{  
+    // If switch_1 = 1 and POT value > 3V, display error message
+    if(switch_1_state == 1 && analogue_1_val > 3)
+    {
+        //lcd->cls(); // clear display
+        lcd->locate(0,0); // set cursor to location (0,0) - top left corner
+        lcd->printf(".ERREUR");
+    }
+    
+    // If switch 2 is high, return a command to task 5 to do the incrementing pattern every 1.5 seconds
+    if(switch_2_state == 1)
+    {
+        BinEnable = 1;
+    }
+    
+    // If switch 2 is low, stop sending a command to task 5 and light off LEDs
+    else
+    {
+        LEDs = 0;
+        BinEnable = 0;
+        BinCount = 0;
+    }
+}
+
+
+
+// Stop function to stop cyclic executive and close log file
+void Stop()
+{
+    ticker.detach();
+    fprintf(fp, "\n The program did nothing for %d ms, which corresponds to %d percent of the time  \n",NoTask, NoTask/100);    
+    fprintf(fp, "\n PROGRAM STOPPED");
+    fclose(fp);
+    
+}
+
+
+
+//=====================================================================================
+// Subroutines
+//=====================================================================================
+
+// Wait for rising edge
+void WaitRisEdge()
+{
+    // As soon as it gets high, the subroutine will end and the timer will start
+    while(TTL == 0)
+    {        
+            wait_us(SampFreq);        
+    }
+}
+
+
+// Wait for falling edge
+void WaitFalEdge()
+{
+    // As soon as it gets low, the subroutine will end and the timer will start
+    while(TTL == 1)
+    {
+        wait_us(SampFreq);
+    }
+}
\ No newline at end of file

diff -r 000000000000 -r aaddc17011a9 mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Thu Mar 08 16:32:35 2012 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/4c0c40fd0593