protocol.c

#include <msp430x54x.h>
#include <stdio.h>

#include "Main.h"                /* Application Interface Abstraction.        */
#include "SS1BTPS.h"             /* Main SS1 Bluetooth Stack Header.          */
#include "L2CAPServer.h"         /* Application Header.                       */
#include "BTPSKRNL.h"            /* BTPS Kernel Header.                       */

#include "I2C.h"

typedef unsigned char uint8_t;
typedef unsigned short uint16_t;

//packet header variables
int type;
int len;
int seq;
int ownseq = 0;
Word_t g_LCID = 0;
unsigned int g_BluetoothStackID;

// variables used temporary but initialized only once
unsigned char packet[50];

int l2cap_send(unsigned int BluetoothStackID, Word_t LCID, uint8_t *data, uint16_t len);


void send_bt_request(unsigned char payload[], int paylen)
{
	//generate full package
	packet[0] = (type<<5) | (paylen+3);
	packet[1]=  ownseq;
	packet[2] = 0xff;
	memcpy(&packet[3], payload, paylen);
	//send packet

	// actually send the packet
	l2cap_send(g_BluetoothStackID, g_LCID, packet, paylen+3);

	//update ownseq
	ownseq = (ownseq + 1) % 0xFF;
}

void send_bt_response(unsigned char payload[], int paylen)
{
	//generate full package
	packet[0] = (type<<5) | (paylen+3);
	packet[1]=  ownseq;
	packet[2] = seq;
	memcpy(&packet[3], payload, paylen);
	//send packet

	// actually send the packet
	l2cap_send(g_BluetoothStackID, g_LCID, packet, paylen+3);

	//update ownseq
	ownseq = (ownseq + 1) % 0xFF;
}

void gpio_err(unsigned char payload[])	//error occured: not consistent
{
	payload[0] = payload [0] | 64; //ser error bit
	send_bt_response(payload, 2);
}


void get_header(unsigned char packet[])
{
	type = packet[0] >> 5;
	len = packet[0] & 0x1f;
	seq = packet[1];
	/*if(packet[2] != 0xff)	//received seq ack should be 0xff always
		header_err(packet);*/
}

void i2c_write(unsigned char addr, unsigned char command[], int size)		//to correct
{
	unsigned char package[256];
	int txlen = size-1;

	if(I2C_write(addr, &command[1], txlen))	//if return true, an error occured
		package[1] = 0x40;
	else
		package[1] = 0;

	//generate rest of answer
	package[0] = addr;
	memcpy(&package[2], &command[1], txlen);
	//send answer
	send_bt_response(package, txlen+2);
}

void i2c_read(unsigned char addr, unsigned char payload[], int size)
{
	unsigned char package[32];
	unsigned char rxdata[16];
	unsigned char rxlen = payload[0] & 31;
	int txlen = size-1;
	if(!I2C_write(addr, &payload[1], txlen))	//if sendi2c does not fail go on with get
	{
		if(I2C_read(addr, rxdata, rxlen))		//set error bit if geti2c fails
			package[1] = rxlen | 0x40;
		else
			package[1] = rxlen;
	}
	else
		package[1] = rxlen | 0x40;		//sendi2c failed
	//generate answer
	size = 2 + rxlen + txlen;

	package[0] =  (addr | 128);
	memcpy(&package[2], &payload[1],txlen);
	memcpy(&package[2+txlen], rxdata, rxlen);
	//send answer
	send_bt_response(package, size);
}

void i2c_packet(unsigned char payload[], int size)
{
	int rw = payload[0] >> 7;
	unsigned char addr = payload[0] & 0x7f;
	if (rw)
		i2c_read(addr, &payload[1], size-1);
	else
		i2c_write(addr, &payload[1], size-1);
}

void gpio_send(int resp, int port_stat)
{
	if (resp)
	{
		unsigned char payload[2];
		payload[0] = (resp << 7) | 2;
		payload[1] = ~port_stat; //value has to be inverted as we detect low
		send_bt_response(payload, 2);
	}
	else
	{
		unsigned char payload[2];
		payload[0] = (resp << 7) | 2;
		payload[1] = ~port_stat; //value has to be inverted as we detect low
		send_bt_request(payload, 2);
	}
}

void gpio_request(unsigned char payload[])
{
	int pingroup = payload[0] & 31;
	if((payload[0] & 128) == 0 || pingroup != 2 ) //throw an error if not a request or pingroup not 2 as only one supported
		gpio_err(payload);
	gpio_send(1, P2IN);
}

void protocol(unsigned int BluetoothStackID, Word_t LCID, unsigned char packet[], unsigned int size)
{
	get_header(packet);

	switch (type)
	{
	case 0:	//i2c
		i2c_packet(&packet[3], size-3);
		break;

	case 1:	//gpio
		gpio_request(&packet[3]);
		break;

	default:
		break;
	}
}

void send_port2_status(int port_stat)
{
	type = 1;
	gpio_send(0, port_stat);
}



//value of port2 input
unsigned int port2_status;

void port2_poll()
{
	if((P2IN & 0x0F) != port2_status)
	{
		// only check first 4 bits, ignore rest
		port2_status = P2IN & 0x0F;

		if(g_LCID != 0)
		{
			LOG_INFO(("Send port status\r\n"));
			send_port2_status(port2_status);
		}
	}
}

#pragma vector = PORT2_VECTOR
__interrupt void PORT2_ISR(void)
{
	// this is used to wake MSP from low power mode if necessary
	LPM3_EXIT;

	P2IES = P2IN;

	P2IFG = 0;
}




int l2cap_send(unsigned int BluetoothStackID, Word_t LCID, uint8_t *data, uint16_t len)
{
	int retval = L2CA_Data_Write(BluetoothStackID,
					LCID,
					len,
					data);

	if(retval)
	{
		LOG_ERROR(("L2CA_Data_Write failed: error code %d\r\n", retval));

		return 0;
	}

	return 1;
}

void connectionOpened(unsigned int BluetoothStackID, Word_t LCID)
{
	g_BluetoothStackID = BluetoothStackID;
	g_LCID = LCID;
}

void connectionClosed()
{
	g_LCID = 0;
}