void lib_i2c_writereg(unsigned char address, unsigned char reg, unsigned char value)
{
lib_i2c_start((address << 1) + I2C_WRITE);
lib_i2c_write(reg);
lib_i2c_write(value);
lib_i2c_stop();
}
void lib_i2c_writereg(unsigned char address, unsigned char reg, unsigned char value)
{
lib_i2c_start((address << 1) + I2C_WRITE);
lib_i2c_write(reg); // Master Transmit Data ACK
lib_i2c_write(value);
lib_i2c_stop();
}
unsigned char lib_i2c_readreg(unsigned char address,unsigned char reg) {
lib_i2c_start_wait((address<<1)+I2C_WRITE);
lib_i2c_write(reg);
lib_i2c_rep_start((address<<1)+I2C_READ);
unsigned char returnvalue = lib_i2c_readnak();
lib_i2c_stop();
return(returnvalue);
}
void lib_i2c_readdata(unsigned char address,unsigned char reg,unsigned char *data,unsigned char length) {
lib_i2c_start_wait((address<<1)+I2C_WRITE);
lib_i2c_write(reg);
lib_i2c_rep_start((address<<1)+I2C_READ);
while (--length) {
*data++ = lib_i2c_readack();
}
*data = lib_i2c_readnak();
lib_i2c_stop();
}
/*************************************************************************
Issues a start condition and sends address and transfer direction.
return 0 = device accessible, 1= failed to access device
*************************************************************************/
unsigned char lib_i2c_start(unsigned char address)
{
// Send start
I2C_START(I2C);
if (!I2C_WAIT_READY_ERROR(I2C))
return 3;
// transmit address byte + direction
if (lib_i2c_write(address)) // Master Transmit Address ACK
return 2;
return 0;
} /* lib_i2c_start */
/*************************************************************************
Issues a repeated start condition and sends address and transfer direction
Input: address and transfer direction of I2C device
Return: 0 device accessible
1 failed to access device
*************************************************************************/
unsigned char lib_i2c_rep_start(unsigned char address)
{
/* Send data */
I2C_SET_CONTROL_REG(I2C, I2C_STA | I2C_SI);
if (!I2C_WAIT_READY_ERROR(I2C))
return 4;
if(I2C_GET_STATUS(I2C) != 0x10) // Master repeat start
return 3;
// transmit address byte + direction
if (lib_i2c_write(address))
return 2;
return 0;
}
/*************************************************************************
Issues a start condition and sends address and transfer direction.
return 0 = device accessible, 1= failed to access device
*************************************************************************/
unsigned char lib_i2c_start(unsigned char address)
{
// send START condition
SDA_H;
SCL_H;
I2C_delay();
if (!SDA_read)
return 1;
SDA_L;
I2C_delay();
if (SDA_read)
return 1;
SDA_L;
I2C_delay();
// transmit address byte + direction
if (lib_i2c_write(address))
return 2;
return 0;
} /* lib_i2c_start */
char readgps()
{ // returns 1 if new data was read
if (lib_timers_gettimermicroseconds(gpstimer)<50000) return(0); // 20 hz
gpstimer=lib_timers_starttimer();
unsigned char shiftedaddress=I2C_GPS_ADDRESS<<1;
lib_i2c_start_wait(shiftedaddress+I2C_WRITE);
if (lib_i2c_write(I2C_GPS_STATUS_00))
return(0);
lib_i2c_rep_start(shiftedaddress+I2C_READ);
unsigned char gps_status= lib_i2c_readnak();
global.gps_num_satelites = (gps_status & 0xf0) >> 4;
if (gps_status & I2C_GPS_STATUS_3DFIX)
{ //Check is we have a good 3d fix (numsats>5)
long longvalue;
unsigned char *ptr=(unsigned char *)&longvalue;
lib_i2c_rep_start(shiftedaddress+I2C_WRITE);
lib_i2c_write(I2C_GPS_LOCATION);
lib_i2c_rep_start(shiftedaddress+I2C_READ);
*ptr++ = lib_i2c_readack();
*ptr++ = lib_i2c_readack();
*ptr++ = lib_i2c_readack();
*ptr = lib_i2c_readack();
global.gps_current_latitude=lib_fp_multiply(longvalue,27488L); // convert from 10,000,000 m to fixedpointnum
ptr=(unsigned char *)&longvalue;
*ptr++ = lib_i2c_readack();
*ptr++ = lib_i2c_readack();
*ptr++ = lib_i2c_readack();
*ptr = lib_i2c_readnak();
global.gps_current_longitude=lib_fp_multiply(longvalue,27488L); // convert from 10,000,000 m to fixedpointnum
int intvalue;
ptr= (unsigned char *)&intvalue;
lib_i2c_rep_start(shiftedaddress+I2C_WRITE);
lib_i2c_write(I2C_GPS_GROUND_SPEED);
lib_i2c_rep_start(shiftedaddress+I2C_READ);
*ptr++ = lib_i2c_readack();
*ptr++ = lib_i2c_readack();
global.gps_current_speed=intvalue*665L; // convert fro cm/s to fixedpointnum to m/s
ptr= (unsigned char *)&intvalue;
*ptr++ = lib_i2c_readack();
*ptr = lib_i2c_readnak();
global.gps_current_altitude=((fixedpointnum)intvalue)<<FIXEDPOINTSHIFT;
lib_i2c_stop();
return(1);
}
lib_i2c_stop();
return(0);
}
