main.cpp

00001 #include "mbed.h"
00002 #include "rtos.h"
00003 Serial pc(USBTX,USBRX);
00004 InterruptIn irpt_4m_mstr(D11);                                      //I2c interrupt from CDMS
00005 DigitalOut irpt_2_mstr(D12);                                        //I2C interrupt to CDMS
00006 I2CSlave slave (D14,D15);
00007 
00008 const int addr = 0x20;                                            //slave address 
00009 char data_receive;
00010 char data_send;
00011 Thread *ptr_t_i2c;
00012 
00013 Timer t;                  // time taken from isr to reach i2c function
00014 Timer t1;
00015   bool write_ack = 1;
00016         bool read_ack = 1;
00017         char data;
00018         char length = 1;
00019 void T_I2C_SLAVE(void const * args)
00020 {
00021      while(1)
00022     {
00023         Thread::signal_wait(0x1);
00024         wait_us(100);                                               // can be between 38 to 15700
00025         //printf("\n\r check 1\n");
00026         t.stop();
00027         if( slave.receive() == 0) 
00028             //slave.stop();                  
00029         if( slave.receive() == 1)                                     // slave writes to master
00030         {
00031             t1.start();
00032             write_ack=slave.write(&data,length);       
00033             t1.stop();      
00034             //slave.stop();    
00035         }
00036         if( slave.receive()==3 ||  slave.receive()==2)             // slave read 
00037         {
00038             t1.start();
00039             read_ack=slave.read(&data,length);
00040             t1.stop();
00041             //slave.stop();
00042         }   
00043         printf("\n \r %d %d\n",t.read_us(),t1.read_us());
00044         t.reset();
00045         t1.reset(); 
00046         
00047         if(write_ack == 0)
00048             printf("\n\rData sent to CDMS is %c\n",data);
00049         if(read_ack == 0)
00050             printf("\n\r Data received from CDMS is %c \n",data);
00051     }
00052 }
00053 
00054 
00055 void FCTN_ISR_I2C()
00056 {
00057      ptr_t_i2c->signal_set(0x1); 
00058      t.start();
00059 }
00060 
00061 int main()
00062 {
00063    printf("\n\r SLAVE ACTIVATED\n");
00064    slave.address(addr);
00065    //slave.frequency(100000);  
00066    ptr_t_i2c = new Thread(T_I2C_SLAVE);
00067    irpt_4m_mstr.enable_irq();
00068    //irpt_4m_mstr.mode(PullDown);
00069    irpt_4m_mstr.rise(&FCTN_ISR_I2C);
00070    
00071 }