Diff: DataComm.cpp

Revision:

0:60c4436f7667

Child:

1:9cfb17f74dcd

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DataComm.cpp	Thu Mar 19 02:36:11 2015 +0000
@@ -0,0 +1,168 @@
+#include "DataComm.h"
+
+void DataComm::setClockOut(PinName pin)
+{
+    gpio_init_out_ex(&clock_out, pin, 0);        
+}
+
+void DataComm::setClockIn(PinName pin)
+{
+    gpio_init_in(&clock_in, pin);    
+}
+
+void DataComm::setSerialOut(PinName pin)
+{
+    gpio_init_out_ex(&serial_out, pin, 0);        
+}
+
+void DataComm::setSerialIn(PinName pin)
+{
+    gpio_init_in(&serial_in, pin);    
+} 
+
+void DataComm::listen()
+{
+    int pre = 0, data_flag = 1;
+    char temp = 0;
+    
+    while(!pre)
+    {
+        //read in data if clock is 1 and data flag is 1
+        if(gpio_read(&clock_in) && data_flag)
+        {
+            //data is left shifted into our temporary variable.
+            //each new data bit is moved into the least significant bit after the rest of the bits are shifted to the left
+            //data must be sent from the other microcontroller shifted out from the most significant bit to the least significant bit.
+            temp = (temp << 1) + gpio_read(&serial_in);
+            data_flag = 0;
+            if(temp == PREAMBLE)
+            {
+                pre = 1;    
+            }
+        }
+        //when clock returns to low - reset data flag to accept the next bit.
+        if(!gpio_read(&clock_in) && !data_flag)
+        {
+            data_flag = 1;
+        }
+    }    
+}
+
+void DataComm::setClock(int clock)
+{
+    clock_time = clock;
+    skew_time = (clock * 9)/10;   
+}
+
+void DataComm::initiate_connection()
+{
+    int j=128, done=0, skew_flag=0;
+    
+    //output preamble
+    while(!done)
+    {
+        //start timer for clock
+        t.start();
+        //wait until the timer has reached the set time.
+        while(t.read_ms() < clock_time)
+        {
+            //extract data just before clock goes high
+            if(!gpio_read(&clock_out) && skew_flag && t.read_ms() > skew_time)
+            {
+                //extract data bit
+                gpio_write(&serial_out, ((PREAMBLE / j) % 2));
+                skew_flag = 0;
+                j /= 2; //decrement j to get to next bit location
+            }
+        }
+        //stop and reset the timer
+        t.stop();
+        t.reset();
+        //switch clock signal
+        gpio_write(&clock_out, !gpio_read(&clock_out));
+        //reset skew flag
+        skew_flag = 1;
+        //last preamble bit sent - return from function
+        if(j==0)
+        {
+            done = 1;  
+        }
+    }     
+}
+
+void DataComm::setDataSize(int size)
+{
+    data_size = size;    
+}
+
+void DataComm::send_data(char data[])
+{
+    int i=0, j=128, done=0, skew_flag=0;
+    
+    //output data
+    while(!done)
+    {
+        //start timer for clock
+        t.start();
+        //wait until the timer has reached the set time.
+        while(t.read_ms() < clock_time)
+        {
+            //extract data just before clock goes high
+            if(!gpio_read(&clock_out) && skew_flag && t.read_ms() > skew_time)
+            {
+                //extract data bit
+                gpio_write(&serial_out, ((data[i] / j) % 2));
+                skew_flag = 0;
+                j /= 2; //decrement j to get to next bit location
+            }
+        }
+        //stop and reset the timer
+        t.stop();
+        t.reset();
+        //switch clock signal
+        gpio_write(&clock_out, !gpio_read(&clock_out));
+        //reset skew flag
+        skew_flag = 1;
+        //last preamble bit sent - return from function
+        if(j==0)
+        {
+            i++;
+            if(i>data_size)
+                done = 1;
+            j=128;  
+        }
+    }       
+}
+
+char* DataComm::receive_data()
+{
+    int i=0, j=0, done = 0, data_flag = 1;
+    char temp[data_size];
+    
+    while(!done)
+    {
+        //read in data if clock is 1 and data flag is 1
+        if(gpio_read(&clock_in) && data_flag)
+        {
+            //data is left shifted into our temporary variable.
+            //each new data bit is moved into the least significant bit after the rest of the bits are shifted to the left
+            //data must be sent from the other microcontroller shifted out from the most significant bit to the least significant bit.
+            temp[i] = (temp[i] << 1) + gpio_read(&serial_in);
+            data_flag = 0;
+            j++;
+        }
+        //when clock returns to low - reset data flag to accept the next bit.
+        if(!gpio_read(&clock_in) && !data_flag)
+        {
+            data_flag = 1;
+        }
+        if(j>7)
+        {
+            i++;
+            if(i>data_size)
+                done=1;
+            j=0;    
+        }
+    }
+    return temp;       
+}