/* bytedance1.c */ 
/* I just include everything, to be on the safe side. */ 

#include <conio.h>
#include <unistd.h>
#include <dsensor.h>
#include <dmotor.h>
#include <lnp-logical.h>
#include <lnp.h>
#include <dbutton.h>
#include <sys/tm.h>
#include <rom/system.h>
#include <mem.h>
#include <string.h>

/* lnp port definitions */ 
#define MY_PORT   0x1
#define DEST_HOST 0x8
#define DEST_PORT 0x2
#define DEST_ADDR ( DEST_HOST << 4 | DEST_PORT )
/* range of IR sensor */ 
#define IR_NEAR 0
#define IR_FAR  1
          
/* Stuff for receive buffer */ 
int gNewData = 0;
unsigned char gMessagingData[256];
int gDataLength;

/* Incoming packet handler */ 
void packet_handler(const unsigned char* data,
		    unsigned char length, 
		    unsigned char src)
{
  /* If the buffer is full, we just lose the data. */ 
  if(gNewData == 0)
  {
    memcpy(gMessagingData, data, length);
    gDataLength = length;
    /* This is done to wake up the reader process */ 
    gNewData = 1;
  }
}


/* This is the wake-up function that checks for new data. */ 
wakeup_t WaitForData(wakeup_t data)
{
  return gNewData;
}

/* This is the reader function for incoming data */ 
int listen ()
{
  unsigned char c; 
  while (1) {
    /* Waits for a byte */ 
    wait_event(WaitForData, 0);
    /* Processes the byte */ 
    c = gMessagingData[0]; 
    gNewData = 0;
    /* Displays the data */ 
    lcd_int (c); 
    switch(c) {
    case 0: 
      motor_a_dir (brake); 
      motor_c_dir (brake); 
      motor_a_speed(MIN_SPEED); 
      motor_c_speed(MIN_SPEED);
      break; 
    case 1:
      motor_a_dir (fwd); 
      motor_c_dir (fwd); 
      motor_a_speed(MAX_SPEED / 2); 
      motor_c_speed(MAX_SPEED / 2);
      break; 
    case 2: 
      motor_a_dir (rev); 
      motor_c_dir (rev); 
      motor_a_speed(MAX_SPEED / 2); 
      motor_c_speed(MAX_SPEED / 2);
      break; 
    }
  }
}


/* This is the data sender */ 
int talk ()
{
  int i = MY_PORT; 
  int len, result; 
  char send_buffer [8]; 

  while (1) { 
    /* sets i to a new random action */ 
    i = (i + 13) * 3 % 3; 
    send_buffer [0] = i; 
    len = 1; 
    /* This sends a byte to the other process; keeps 
       trying until it succeeds */ 
    do { 
      result = lnp_addressing_write(send_buffer, len, DEST_ADDR, MY_PORT);
      /* waits between attempts */ 
      msleep (500); 
    } while (result); 
  }
}


int main() 
{    
  pid_t pid1, pid2; 
  /* Sets the IR distance */ 
  lnp_logical_range(IR_FAR);
  /* Sets the packet handler */ 
  lnp_addressing_set_handler (MY_PORT, packet_handler);
  /* Spawns the processes that talk, and listen */ 
  pid1=execi(&talk,   0, NULL, 1, DEFAULT_STACK_SIZE);
  pid2=execi(&listen, 0, NULL, 1, DEFAULT_STACK_SIZE);  
  return 0;
}