void timerIRP(void)
{
unsigned char i;
unsigned char key;
static unsigned char key_last;
static unsigned char key_val;
static unsigned char key_dm_ctr = 0;

	i = adcRead();
	if (i < 128)
		key = 1;
	else if (i < 388)
		key = 2;
	else if (i < 683)
		key = 3;
	else if (i < 995)
		key = 4;
    	else
       	key = 0;
		
	adcStart(ADC_CH_KEY);

	if (key_last == key)
	{            
		if (key != 0)
		{
		if (key_dm_ctr == 0)
		{
			key_val = key;
		}
		
		if (key_dm_ctr != 0xff)
 			key_dm_ctr++;
 			
		if (key_dm_ctr == 100)
		{
		
		}
	}
	
	else
	{
		if (key_val)
		{
			if (key_dm_ctr < 100)
			send_msg(&msg_key, key_val);
			key_val = 0;
		}
		key_dm_ctr = 0;
		}
	}
	
	key_last = key;
	
}