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#include <xc.h>
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#include "defines.h"
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#include "base_CPS.h"
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static CPS_DATA *cps_data_p;
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void CPS_Init(CPS_DATA* data) {
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cps_data_p = data;
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for (char i = 0; i < 4; i++) {
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cps_data_p->btn_pressed[i] = 0;
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cps_data_p->btn_last_value[i] = 0;
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cps_data_p->btn_avg_value[i] = 0;
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cps_data_p->btn_pct_value[i] = 0;
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}
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/* Initialize port direction */
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CPS_0_TRIS = 1;
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CPS_1_TRIS = 1;
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/* Initialize FVR for the upper threshold (Ref+) */
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FVRCONbits.CDAFVR = 0b01; // Gain of 1x (1.024V)
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FVRCONbits.FVREN = 1; // Enable FVR module
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/* Initialize DAC for the lower threshold (Ref-) */
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DACCON0bits.DACEN = 0; // Disable DAC
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DACCON0bits.DACLPS = 0; // Negative reference source selected
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DACCON0bits.DACOE = 0; // Output not routed to DACOUT pin
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DACCON0bits.DACPSS = 0b00; // Vdd used as positive source
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// DACCON0bits.DACNSS = 0; // Vss used as negative source
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DACCON1bits.DACR = 0b00000; // Voltage output set to 0
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/* Initialize Timer 0 */
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OPTION_REGbits.TMR0CS = 0; // Clock source is FOSC/4
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OPTION_REGbits.PSA = 0; // Prescaler enabled
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OPTION_REGbits.PS = 0b111; // Prescaler of 1:256
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/* Initialize Timer 1 */
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T1CONbits.TMR1CS = 0b11; // Clock source is Capacitive Sensing Oscillator
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T1CONbits.T1CKPS = 0b00; // 1:1 Prescale value
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T1GCONbits.TMR1GE = 1; // Counting is controlled by the gate function
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T1GCONbits.T1GPOL = 1; // Gate is active high
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T1GCONbits.T1GTM = 1; // Gate toggle mode is enabled
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T1GCONbits.T1GSPM = 0; // Gate single-pulse mode is disabled
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T1GCONbits.T1GSS = 0b01; // Gate source is Timer 0 overflow
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T1CONbits.TMR1ON = 1; // Enables timer 1
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/* Initialize CPS Module */
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CPSCON0bits.CPSRM = 1; // DAC and FVR used for Vref- and Vref+
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CPSCON0bits.CPSRNG = 0b11; // Osc in high range (100uA)
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CPSCON0bits.T0XCS = 0; // Timer 0 clock runs at FOSC/4
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CPSCON1bits.CPSCH = 0b00; // Channel 0 (CPS0)
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cps_data_p->channel = 0;
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CPSCON0bits.CPSON = 1; // CPS module is enabled
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/* Initialize timer interrupts and clear timers */
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INTCONbits.TMR0IE = 1; // Timer 0 interrupt enabled
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PIE1bits.TMR1IE = 0; // Timer 1 interrupt disabled
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CPS_Reset();
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}
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void CPS_Timer_0_Interrupt_Handler() {
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unsigned int value = TMR1;
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long percent;
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if (value < 10) {
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return;
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}
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// Calculate percentage change
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percent = (long)cps_data_p->btn_avg_value[cps_data_p->channel]-(long)value;
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if (percent < 0)
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percent = 0;
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else {
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percent *= 100;
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percent /= cps_data_p->btn_avg_value[cps_data_p->channel];
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}
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cps_data_p->btn_last_value[cps_data_p->channel] = value;
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cps_data_p->btn_pct_value[cps_data_p->channel] = percent;
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if (percent < CPS_PCT_OFF) {
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// Calculate average
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cps_data_p->btn_avg_value[cps_data_p->channel] =
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cps_data_p->btn_avg_value[cps_data_p->channel] +
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((long)value - (long)cps_data_p->btn_avg_value[cps_data_p->channel])
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/CPS_AVG_COUNT;
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// Set flag to indicate that button is not pressed
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cps_data_p->btn_pressed[cps_data_p->channel] = 0;
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} else if (percent > CPS_PCT_ON)
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// Set flag to indicate that button was pressed
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cps_data_p->btn_pressed[cps_data_p->channel] = 1;
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cps_data_p->channel = cps_data_p->channel + 1;
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if (cps_data_p->channel == CPS_NUM_CHANNELS)
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cps_data_p->channel = 0;
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CPSCON1bits.CPSCH = cps_data_p->channel;
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CPS_Reset();
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}
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void CPS_Reset() {
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TMR1 = 0;
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TMR0 = 0;
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}
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void CPS_Enable() {
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INTCONbits.TMR0IE = 1; // Timer 0 interrupt enabled
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T1CONbits.TMR1ON = 1;
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CPSCON0bits.CPSON = 1;
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CPS_Reset();
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}
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void CPS_Disable() {
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INTCONbits.TMR0IE = 0;
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CPSCON0bits.CPSON = 0;
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T1CONbits.TMR1ON = 0;
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}
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