//*****************************************************************************
//
// This function prepares the quadrature encoder module for capturing the
// position and speed of the motor.
//
//*****************************************************************************
void
EncoderInit(void)
{
//
// Configure the QEI pins.
//
ROM_GPIOPinTypeQEI(QEI_PHA_PORT, QEI_PHA_PIN);
ROM_GPIOPinTypeQEI(QEI_PHB_PORT, QEI_PHB_PIN);
ROM_GPIOPinTypeQEI(QEI_INDEX_PORT, QEI_INDEX_PIN);
//
// Configure the QEI module.
//
ROM_QEIConfigure(QEI0_BASE,
(QEI_CONFIG_RESET_IDX | QEI_CONFIG_CAPTURE_A |
QEI_CONFIG_QUADRATURE | QEI_CONFIG_NO_SWAP), 0xffffffff);
//
// Initialize the QEI position to zero.
//
ROM_QEIPositionSet(QEI0_BASE, 0);
//
// Enable the QEI module.
//
ROM_QEIEnable(QEI0_BASE);
//
// Configure the encoder input to generate an interrupt on every rising
// edge.
//
ROM_GPIOIntTypeSet(QEI_PHA_PORT, QEI_PHA_PIN, GPIO_RISING_EDGE);
ROM_GPIOPinIntEnable(QEI_PHA_PORT, QEI_PHA_PIN);
ROM_IntEnable(QEI_PHA_INT);
}
// * enc_init *****************************************************************
// * Setup pins and hardware to read quadrture encoders. Setup causes each *
// * encoder line to result in 4 pulses, i.e. a 100line encoder would yield *
// * 400 pulses/revolution. *
// * Assumes system clock already configured *
// ****************************************************************************
void enc_init(void)
{
unsigned long config_temp; // used when assembling configuration values
// setup pins for QEI
// ENC_1-------------------------------
ROM_SysCtlPeripheralEnable(ENC_1_PORT); // enable clock to GPIO port
//ROM_SysCtlPeripheralReset(ENC_1_PORT); // reset to clear any previous configuration
// configure input pads
ROM_GPIOPinConfigure(ENC_1_B_MUX); // select mux for qei input
ROM_GPIOPinConfigure(ENC_1_A_MUX); // select mux for qei input
ROM_GPIOPinConfigure(ENC_1_INDEX_MUX); // select mux for qei input
// copy and pasted from GPIOPinTypeQEI,
// modified to have no pull up/down resistors.
GPIODirModeSet(ENC_1_PORT_BASE, ENC_1_PINS, GPIO_DIR_MODE_HW);
// QEI pin tristates under HW control.
GPIOPadConfigSet(ENC_1_PORT_BASE, ENC_1_PINS, GPIO_STRENGTH_2MA, GPIO_PIN_TYPE_STD);
// Note, output drive config only configs
// pull up/down resistors when pin is input.
// ENC_2-------------------------------
ROM_SysCtlPeripheralEnable(ENC_2_PORT); // enable clock to GPIO port
//ROM_SysCtlPeripheralReset(ENC_2_PORT); // reset to clear any previous configuration
// configure input pads
ROM_GPIOPinConfigure(ENC_2_B_MUX); // select mux for qei input
//ROM_GPIOPinConfigure(ENC_2_A_MUX); // select mux for qei input WORKAROUND FOR DEAD PIN
ROM_GPIOPinConfigure(ENC_2_INDEX_MUX); // select mux for qei input
// copy and pasted from GPIOPinTypeQEI,
// modified to have no pull up/down resistors.
GPIODirModeSet(ENC_2_PORT_BASE, ENC_2_PINS, GPIO_DIR_MODE_HW);
// QEI pin tristates under HW control.
GPIOPadConfigSet(ENC_2_PORT_BASE, ENC_2_PINS, GPIO_STRENGTH_2MA, GPIO_PIN_TYPE_STD);
//GPIODirModeSet(ENC_2_PORT_BASE, ENC_2_PINS, GPIO_DIR_MODE_IN);//DEBUG
//DEBUG
// Note, output drive config only configs
// pull up/down resistors when pin is input.
// ENC_2 DEAD PIN WORKAROUND SETUP-----
ROM_SysCtlPeripheralEnable(ENC_2_PORT_2); // enable clock to GPIO port
// configure input pads
ROM_GPIOPinConfigure(ENC_2_A_MUX); // select mux for qei input WORKAROUND FOR DEAD PIN
// copy and pasted from GPIOPinTypeQEI,
// modified to have no pull up/down resistors.
GPIODirModeSet(ENC_2_PORT_BASE_2, ENC_2_PINS_2, GPIO_DIR_MODE_HW);
// QEI pin tristates under HW control.
GPIOPadConfigSet(ENC_2_PORT_BASE_2, ENC_2_PINS_2, GPIO_STRENGTH_2MA, GPIO_PIN_TYPE_STD);
// setup QEI modules
// ENC_1-------------------------------
ROM_SysCtlPeripheralEnable(ENC_1_MODULE); // enable clock to QEI
ROM_QEIConfigure(ENC_1_BASE, (QEI_CONFIG_CAPTURE_A_B | // configure QEI
QEI_CONFIG_NO_RESET |
QEI_CONFIG_QUADRATURE |
QEI_CONFIG_NO_SWAP),
ENC_MAX_POSITION);
ROM_QEIVelocityConfigure(ENC_1_BASE,QEI_VELDIV_1, // configure hardware velocity capture
ENC_VEL_PERIOD);
ROM_QEIVelocityEnable(ENC_1_BASE); // enable velocity capture
// enable digital filter on input
config_temp = HWREG(ENC_1_BASE + QEI_O_CTL); // grab copy of the QEI's control register
config_temp |= ENC_FILT_ENA_BITS; // configure and enable digital persistence filter
HWREG(ENC_1_BASE + QEI_O_CTL) = config_temp; // write modified value back to register
// ENC_2-------------------------------
ROM_SysCtlPeripheralEnable(ENC_2_MODULE); // enable clock to QEI
ROM_QEIConfigure(ENC_2_BASE, (QEI_CONFIG_CAPTURE_A_B | // configure QEI
QEI_CONFIG_NO_RESET |
QEI_CONFIG_QUADRATURE |
QEI_CONFIG_NO_SWAP),
ENC_MAX_POSITION);
ROM_QEIVelocityConfigure(ENC_2_BASE,QEI_VELDIV_1, // configure hardware velocity capture
ENC_VEL_PERIOD);
ROM_QEIVelocityEnable(ENC_2_BASE); // enable velocity capture
// enable digital filter on input
config_temp = HWREG(ENC_2_BASE + QEI_O_CTL); // grab copy of the QEI's control register
config_temp |= ENC_FILT_ENA_BITS; // configure and enable digital persistence filter
HWREG(ENC_2_BASE + QEI_O_CTL) = config_temp; // write modified value back to register
ROM_QEIEnable(ENC_1_BASE); // Enable one QEI after the other.
ROM_QEIEnable(ENC_2_BASE); // Try to keep sync, later we will assume ENC_2
// velocity capture finishes just after ENC_1,
// so we will interrupt off ENC_2's velocity timer.
}
