uint16_t max31855_read()
{
MAX31855_t max31855;
uint8_t data[4];
//Switch CS to low to initiate data transfer
MAX31855_CS_PORT &= ~(1<<MAX_31855_CS_PIN_1);
//Get bits D31 to D24
spi_master_transmit(0xFF);
data[0] = SPDR;
//Get bits D23 to D16
spi_master_transmit(0xFF);
data[1] = SPDR;
//Get bits D15 to D8
spi_master_transmit(0xFF);
data[2] = SPDR;
//Get bits D7 to D0
spi_master_transmit(0xFF);
data[3] = SPDR;
//Switch CS back to high to end data transfer
MAX31855_CS_PORT |= (1<<MAX_31855_CS_PIN_1);
#ifdef DEBUG_BUILD
char buffer[8];
uart0_print("Raw Value: ");
itoa(data[0], buffer, 16); uart0_print(buffer); uart0_print(" ");
itoa(data[1], buffer, 16); uart0_print(buffer); uart0_print(" ");
itoa(data[2], buffer, 16); uart0_print(buffer); uart0_print(" ");
itoa(data[3], buffer, 16); uart0_print(buffer); uart0_print(" ");
uart0_print(", ");
#endif
//The two most significant bytes hold the thermocouple temp
max31855.thermocoupleTemp = ((data[0]<<8)|(data[1]));
//Check if the value is negative
if((max31855.thermocoupleTemp & 0x8000) == 0x8000)
max31855.signBit = 1;
//Check if the fault bit(Bit 16) is 1
if((max31855.thermocoupleTemp & 0x0001) == 0x0001)
{
max31855.faultBit = 1;
#ifdef DEBUG_BUILD
uart0_print("Fault Detected, ");
#endif
}
//Shift out bits D16 and D17
max31855.thermocoupleTemp = (max31855.thermocoupleTemp >> 2);
return max31855.thermocoupleTemp;
}
uint8_t knock_module_initialize(void)
{
uint8_t i, response;
uint8_t init_data[2] = {KSP_SET_PRESCALER | KSP_PRESCALER_VALUE | KSP_SO_TERMINAL_ACTIVE,
KSP_SET_CHANNEL | KSP_CHANNEL_0};
uint8_t _t;
_t=_SAVE_INTERRUPT();
_DISABLE_INTERRUPT();
//Setting HOLD mode for integrator and "Run" mode for chip at all.
SET_KSP_TEST(1);
SET_KSP_INTHOLD(KNOCK_INTMODE_HOLD);
SET_KSP_CS(1);
spi_master_init();
ksp.ksp_interrupt_state = 0; //init state machine
ksp.ksp_error = 0;
//set prescaler first
SET_KSP_CS(0);
spi_master_transmit(init_data[0]);
SET_KSP_CS(1);
//Setting SO terminal active and perform initialization. For each parameter perform
//checking for response and correcntess of received data.
for(i = 0; i < 2; ++i)
{
SET_KSP_CS(0);
spi_master_transmit(init_data[i]);
SET_KSP_CS(1);
response = SPDR;
if (response!=init_data[i])
{
_RESTORE_INTERRUPT(_t);
return 0; //error - chip doesn't respond!
}
}
_RESTORE_INTERRUPT(_t);
//Initialization completed successfully
return 1;
}
