/*************************************************************************
Author: Josiah Snarr
Date: April 9, 2015
DACSend forms a header for data sent to the DAC, and sends the data with
the specified instruction (0 - LDAB, 1 - LDA, 2 - LDB)
*************************************************************************/
void DACSend(unsigned char dVal, unsigned char inst)
{
char lss; //Least significant set to send
char mss; //Most significant set to send
switch(inst) //Find command and form MSB side of header
{
case COM_LDA:
mss = (DAC_COM_LDA | (HI_NYBBLE(dVal)));
break;
case COM_LDB:
mss = (DAC_COM_LDB | (HI_NYBBLE(dVal)));
break;
case COM_LDAB:
mss = (DAC_COM_LDAB | (HI_NYBBLE(dVal)));
break;
default:
break;
}
lss = (NYB_CAT(dVal, LSB_FRAME)); //Form LSB side of header
//Push output to DAC
CLR_BITS(SPI_PORT, SPI_SS);
putSPI(mss);
putSPI(lss);
SET_BITS(SPI_PORT, SPI_SS);
}
/*************************************************************************
Author: Josiah Snarr
Date: April 9, 2015
DACShutdown shuts down the DAC
*************************************************************************/
void DACShutdown(void)
{
CLR_BITS(SPI_PORT, SPI_SS);
putSPI(DAC_COM_SHUT);
putSPI(LSB_FRAME);
SET_BITS(SPI_PORT, SPI_SS);
}
/*************************************************************************
Author: Josiah Snarr
Date: April 9, 2015
DACStandby puts the DAC on standby
*************************************************************************/
void DACStandby(void)
{
CLR_BITS(SPI_PORT, SPI_SS);
putSPI(DAC_COM_STAN);
putSPI(LSB_FRAME);
SET_BITS(SPI_PORT, SPI_SS);
}
/*************************************************************************
Author: Josiah Snarr
Date: April 9, 2015
DACWake wakes the DAC
*************************************************************************/
void DACWake(void)
{
CLR_BITS(SPI_PORT, SPI_SS);
putSPI(DAC_COM_WAKE);
putSPI(LSB_FRAME);
SET_BITS(SPI_PORT, SPI_SS);
}
/**
* For talking to the MCP4822 DAC
*/
void DAC_updateVoltage(uint16_t channel, uint16_t value) {
// Validate channel selection
if(channel <= 1) {
// Cap value to 12 bits only
if(value > 0x0FFF) {
value = 0x0FFF;
}
char txBuf[2];
uint16_t cmd = 0x3000 | (value & 0x0FFF);
if(channel) cmd |= 0x8000;
txBuf[1] = cmd & 0x00FF;
txBuf[0] = __swap_bytes(cmd) & 0x00FF;
CLR_BITS(SPI_PORT(OUT),SSEL | nLDAC); // CS~ falling edge, hold nLDAC low
SPI_send(txBuf, 2);
SET_BITS(SPI_PORT(OUT),SSEL); // CS~ Rising edge. Because nLDAC is low, DAC output changes on rising CS~ edge.
}
}
void timer_init(void)
{
TIMER_SET_PRESCALER(TIMER_PRESCALER_64);
TIMER_DISABLE_ON_FREEZE();
TIMER_FANCY_FAST_CLEAR();
TIMER_ENABLE();
CLR_BITS(TIE, (TIE_C3I_MASK));
}
/* Initialize SCI module */
void SCIinit(void) {
SET_SCI_BAUD(BAUD38400); // Set baud rate
CLR_BITS(SCICR1,SCICR1_INIT); // Set port configuration
SCIflush();
SCI_RX_INT_ENABLE; // Enable SCI receive interrupt
SET_BITS(SCICR2,( SCICR2_RE_MASK | SCICR2_TE_MASK )); // Enable transmitter and receiver
SCIcount = 0; // Clear SCI received bytes counter
}
/* Stepper motor control interrupt handler */
interrupt VECTOR_NUM(TC_VECTOR(TC_STEPPER)) void StepperISR(void) {
static byte stepper_count = 0;
TC(TC_STEPPER) += TIMER_DELTA(stepper_delay); // Acknowledge interrupt and set delta for next event
FORCE_BITS(STEPPER_PORT,STEPPER_COIL_BITS,(STEPPER_PATTERN[stepper_count] << 4)); // Change bit pattern on stepper coils
/* ADD CHECKING OF LIMITS IN HERE SO THAT STEPPER DOES NOT TRY TO GO PAST PHYSICAL LIMITS */
if(stepper_position != stepper_setpoint || stepper_calibrated == 0) {
/* Stepper not at set point or not calibrated */
stepper_count = (stepper_count + stepper_step_type) & STEPPER_COUNT_MASK; // Set offset to next step pattern and mask off bits to keep value in range
stepper_position += stepper_step_type;
} else {
/* Stepper is at set point */
if(stepper_count % 2) CLR_BITS(STEPPER_PORT,STEPPER_COIL_BITS); // Turn off coils on odd numbers (50% duty cycle)
}
}
/*************************************************************************
Author: Josiah Snarr
Date: April 11, 2015
stepperInit initializes the ports which the stepper motor uses, PORTT and
PORTAD
*************************************************************************/
void stepperInit(void)
{
SET_BITS(STEP_DDR, STEP_OUT);
SET_BITS(SMEN_DDR, SMEN_MASK);
SET_BITS(STEP_SWI_DIS, STEP_SWI_IN);
CLR_BITS(STEP_SWI_DDR, STEP_SWI_IN);
MAKE_CHNL_OC(TIOS_IOS4_MASK);
TIE &= (~((unsigned char)TIOS_IOS4_MASK)); //Disable interrupts
SET_BITS(SMEN_PORT, SMEN_MASK);
//Initial direction left, and start at beginning of table
direction = DIR_LEFT;
stepIndex = 0;
stepperHome();
}
/*************************************************************************
Author: Josiah Snarr
Date: April 9, 2015
putcSPI pushes a byte-long value through the SPI interface with SS low
*************************************************************************/
void putcSPI(unsigned char val)
{
CLR_BITS(SPI_PORT, SPI_SS);
putSPI(val);
SET_BITS(SPI_PORT, SPI_SS);
}
