2004 Microchip Technology Inc.
DS00908A-page 31
AN908
SEVTCMPbits.SEVTDIR = 0;
// ============= Encoder ===============
MAXCNT = MotorParm.iCntsPerRev;
POSCNT = 0;
QEICON = 0;
QEICONbits.QEIM = 7; // x4 reset by MAXCNT pulse
QEICONbits.POSRES = 0; // Don't allow Index pulse to reset counter
QEICONbits.SWPAB = 0; // direction
DFLTCON = 0; // Digital filter set to off
// ============= ADC - Measure Current & Pot ======================
// ADC setup for simultanous sampling on
//
CH0=AN7, CH1=AN0, CH2=AN1, CH3=AN2.
// Sampling triggered by PWM and stored in signed fractional form.
ADCON1 = 0;
// Signed fractional (DOUT = sddd dddd dd00 0000)
ADCON1bits.FORM = 3;
// Motor Control PWM interval ends sampling and starts conversion
ADCON1bits.SSRC = 3;
// Simultaneous Sample Select bit (only applicable when CHPS = 01 or 1x)
// Samples CH0, CH1, CH2, CH3 simultaneously (when CHPS = 1x)
// Samples CH0 and CH1 simultaneously (when CHPS = 01)
ADCON1bits.SIMSAM = 1;
// Sampling begins immediately after last conversion completes.
// SAMP bit is auto set.
ADCON1bits.ASAM = 1;
ADCON2 = 0;
// Samples CH0, CH1, CH2, CH3 simultaneously (when CHPS = 1x)
ADCON2bits.CHPS = 2;
ADCON3 = 0;
// A/D Conversion Clock Select bits = 8 * Tcy
ADCON3bits.ADCS = 15;
/* ADCHS: ADC Input Channel Select Register */
ADCHS = 0;
// CH0 is AN7
ADCHSbits.CH0SA = 7;
// CH1 positive input is AN0, CH2 positive input is AN1, CH3 positive input is AN2
ADCHSbits.CH123SA = 0;
/* ADPCFG: ADC Port Configuration Register */
// Set all ports digital
ADPCFG = 0xFFFF;
ADPCFGbits.PCFG0 = 0; // AN0 analog
ADPCFGbits.PCFG1 = 0; // AN1 analog
ADPCFGbits.PCFG2 = 0; // AN2 analog
ADPCFGbits.PCFG7 = 0; // AN7 analog
/* ADCSSL: ADC Input Scan Select Register */
ADCSSL = 0;
// Turn on A/D module
ADCON1bits.ADON = 1;
#ifdefDIAGNOSTICS
// Initialize Output Compare 7 and 8 for use in diagnostics.
