Diff: MS3DMGX2.cpp

Revision:

1:555c2c2bf9d3

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MS3DMGX2.cpp	Sun Feb 13 10:49:06 2011 +0000
@@ -0,0 +1,224 @@
+#include "MS3DMGX2.h"
+
+MS3DMGX2::MS3DMGX2(PinName tx, PinName rx) : DataLines(tx, rx),
+    CommandByte(0xCF), ResponseLength(6), PacketSize(31), Continuous(0)//,
+    
+    ///////////////////
+    //PC(USBTX,USBRX)
+    //////////////////
+    
+{
+    DataLines.baud(115200);
+    DataLines.format(8, Serial::None, 1);
+    DataLines.attach(this, &MS3DMGX2::FillSerialBuffer, Serial::RxIrq);
+        
+        ////////////////////
+    //PC.baud(9600);
+    ////////////////////////
+}
+
+MS3DMGX2::~MS3DMGX2()
+{
+    delete this;
+}
+
+bool MS3DMGX2::Mode(unsigned char Selection)
+{
+    bool Result;
+    switch (Selection & 0x03)
+    {
+        case 0x00:
+            CommandByte = 0xCF;
+            ResponseLength = 6;
+            PacketSize = 31;
+            break;
+                //euler angles and angular rates
+        case 0x01:
+            CommandByte = 0xD2;
+            ResponseLength = 9;
+            PacketSize = 43;
+            break;
+                //gyro-stabilized acceleration, angular rate and magnetometer vector
+        case 0x02:
+            CommandByte = 0xC8;
+            ResponseLength = 15;
+            PacketSize = 67;
+            break;
+                //acceleration, angular rate and orientation matrix
+        case 0x03:
+            CommandByte = 0xCC;
+            ResponseLength = 18;
+            PacketSize = 79;
+            break;
+                //acceleration, angular rate, magnetometer vector, and orientation matrix
+    }
+        //record desired packet command and packet length as number of 16 bit fields
+    if (Selection & 0x04)
+    {
+        unsigned char lbuff = PacketSize;
+        PacketSize = 87;
+        
+        DataLines.putc(0xC4);
+        DataLines.putc(0xC1);
+        DataLines.putc(0x29);
+        DataLines.putc(CommandByte);
+            //send the desired continuous mode command
+        Continuous = 1;
+            //set synchronous mode to true
+        while ((Buffer[BufferStart] != 0xC4) || (Buffer[BufferStart + 1] != CommandByte))
+        {
+            if (((BufferStart + 2) % PacketSize) != BufferEnd)
+            {
+                BufferStart++;
+                BufferStart%=PacketSize;
+            }
+        }
+            //find the response header
+        while (((BufferStart + 8) % PacketSize) != BufferEnd);
+        BufferEnd = 0;
+        Result = Checksum(BufferStart, 8);
+        BufferStart = 0;
+        PacketSize = lbuff;////////////////NOTE: if there wasn't a packet waiting while the async cmd was made, there will be no "extra data" here
+    }
+    else
+    {
+        if (Continuous)
+        {
+            DataLines.putc(0xFA);
+                //send stop continuous mode command
+            Continuous = 0;
+                //set synchronous mode to true
+        }
+        Result = 1;
+    }
+        //put the IMU into continuous mode if the correct flag is set
+        //Computer.printf("stop command success %d \n", Workspace[0]);
+        //Computer.printf("sync mode %d \n", SyncMode);
+    /*if (Selection & 0x08)
+    {
+        DataLines.attach(this, &MS3DMGX2::Interrupt, Serial::RxIrq);
+            //attach automatic buffer-writing function to serial interrupt
+    }
+    else
+    {
+        DataLines.attach(NULL, Serial::RxIrq);
+            //attach a null to detach any previous interrupt
+    }*/
+        //attaches or detaches interrupt function depending on interrupt flag
+    return Result;
+        //return success or failure
+}
+
+bool MS3DMGX2::Readable()
+{
+    return BufferStart == BufferEnd;
+}
+
+/*void MS3DMGX2::AttachInterruptBuffer(float* Buffer)
+{
+    InterruptBuffer = Buffer;
+}
+    //store user's data pointer for use in interrupt modes
+
+void MS3DMGX2::AttachInterruptFunction()
+{
+    DataLines.attach(this, &MS3DMGX2::Interrupt, Serial::RxIrq);
+}
+void MS3DMGX2::AttachInterruptFunction(void (*Function)())
+{
+    DataLines.attach(Function);
+}
+template<class Class> void AttachInterruptFunction(Class* Object, void (Class::*Function)())
+{
+    DataLines.attach(Object, Function, Serial::RxIrq);
+}*/
+    //overloads start interrupt modes, allowing user all possible options
+
+void MS3DMGX2::RequestSyncRead()
+{
+    if (Continuous)
+    {
+        DataLines.putc(0xFA);
+        Continuous = 0;
+    }
+    DataLines.putc(CommandByte);
+}
+    //lazy switches to synchronous mode and sends polled mode command byte
+
+bool MS3DMGX2::Read(float* Data)
+{
+    bool Result;
+    unsigned char t = 0;
+    
+    while ((Buffer[BufferStart] != CommandByte) && (t < PacketSize))
+    {
+        BufferStart++;
+        BufferStart %= PacketSize;
+        t++;
+    }
+        //find the header byte
+    Result = Checksum(BufferStart, PacketSize);
+        //compute checksum
+    BufferStart++;
+    BufferStart %= PacketSize;
+        //move past header byte
+    if (t < PacketSize)
+    {
+        for (unsigned int i = 0; i < ResponseLength; i++)
+        {
+            for(unsigned int j = 3; j < 4; j--)
+            {
+                ((unsigned char*)&Data[i])[j] = Buffer[BufferStart];
+                BufferStart++;
+                BufferStart %= PacketSize;
+            }
+        }
+            //convert big endian bytes to little endian floats
+        BufferStart += 6;
+            //move index past timer and checksum bytes
+        BufferStart %= PacketSize;
+    }
+        //if the header search did not timeout
+    
+    return Result;
+}
+
+/*MS3DMGX2::operator float*()
+{
+    Read((float*)&Workspace[8]);
+    return (float*)&Workspace[8];
+}
+    //conversion function acts as shorthand for Read()
+
+void MS3DMGX2::Interrupt()
+{
+    Read(InterruptBuffer);
+}*/
+    //this will be called when in an interrupt mode and a serial interrupt is generated
+
+bool MS3DMGX2::Checksum(unsigned char Index, unsigned char Length)
+{
+    unsigned short Sum = 0;
+    for (unsigned char i = 0; i < Length - 2; i++)
+    {
+        Sum += Buffer[Index];
+        Index++;
+        Index %= PacketSize;
+    }
+    return (((unsigned char*)&Sum)[0] == Buffer[Index+1])
+        && (((unsigned char*)&Sum)[1] == Buffer[Index]);
+}
+
+void MS3DMGX2::FillSerialBuffer()//if the interrupt recurs faster than the time to complete its code, the rest of the system will be suspended indefinitely
+{
+    while (DataLines.readable())
+    {
+        Buffer[BufferEnd] = DataLines.getc();
+        BufferEnd++;
+       
+        BufferEnd %= PacketSize;
+    }
+}
+    //this automatically reads in new serial data as it is received to
+    //make a software buffer that is big enough to handle an entire
+    //packet; the processor is about 1000 times faster than the data lines
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