Adc.rar_pickit3

#include<p18f45k20.h> typedef enum { LEFT2RIGHT, RIGHT2LEFT} LEDDirections; typedef enum {FALSE, TRUE} BOOL; #define Switch_Pin PORTBbits.RB0 #define DetectsInARow 5 void Timer0_Init(void); void ADC_Init(void); unsigned char ADC_Convert(void); unsigned char LED_Display; void main (void) { LEDDirections Direction = RIGHT2LEFT; BOOL SwitchPressed = FALSE; LED_Display = 1; // initialize // Init I/O TRISD = 0b00000000; // PORTD bits 7:0 are all outputs (0) TRISAbits.TRISA0 = 1; // TRISA0 input INTCON2bits.RBPU = 0; // enable PORTB internal pullups WPUBbits.WPUB0 = 1; // enable pull up on RB0 // ADCON1 is now set up in the InitADC() function. TRISBbits.TRISB0 = 1; // PORTB bit 0 (connected to switch) is input (1) // Init Timer0 Timer0_Init(); // Init ADC ADC_Init(); while (1) { if (Direction == LEFT2RIGHT) { LED_Display <<= 1; // rotate display by 1 from 0 to 7 if (LED_Display == 0) LED_Display = 1; // rotated bit out, so set bit 0 } if (Direction == RIGHT2LEFT) { LED_Display >>= 1; // rotate display by 1 from 7 to 0 if (LED_Display == 0) LED_Display = 0x80; // rotated bit out, so set bit 7 } LATD = LED_Display; // output LED_Display value to PORTD LEDs do { // poll the switch while waiting for the timer to roll over. if (Switch_Pin == 1) { // look for switch released. SwitchPressed = FALSE; } else if (SwitchPressed == FALSE) // && (Switch_Pin == 0) due to if-else { // switch was just pressed SwitchPressed = TRUE; // change direction if (Direction == LEFT2RIGHT) Direction = RIGHT2LEFT; else Direction = LEFT2RIGHT; } } while (INTCONbits.TMR0IF == 0); // Timer expired INTCONbits.TMR0IF = 0; // Reset Timer flag // Take an ADC conversion and use it to set Timer0 TMR0H = ADC_Convert(); // MSB from ADC TMR0L = 0; // LSB = 0 } } void Timer0_Init(void) { INTCONbits.TMR0IF = 0; // clear roll-over interrupt flag T0CON = 0b00000001; // prescale 1:4 - about 1 second maximum delay. TMR0H = 0; // clear timer - always write upper byte first TMR0L = 0; T0CONbits.TMR0ON = 1; // start timer } void ADC_Init(void) { // initialize the Analog-To-Digital converter. // First, we need to make sure the AN0 pin is enabled as an analog input // as the demo board potentiometer is connected to RA0/AN0 // Don't forget that RB0/AN12 must be digital! ANSEL = 0; //turn off all other analog inputs ANSELH = 0; ANSELbits.ANS0 = 1; // turn on RA0 analog // Sets bits VCFG1 and VCFG0 in ADCON1 so the ADC voltage reference is VSS to VDD ADCON1 = 0; // The ADC clock must as short as possible but still greater than the // minimum TAD time, datasheet parameter 130. At the time this lesson was // written TAD minimum for the PIC18F45K20 is 1.4us. // At 1MHz clock, selecting ADCS = FOSC/2 = 500kHz. One clock period // 1 / 500kHz = 2us, which greater than minimum required 1.4us. // So ADCON2 bits ADCS2-0 = 000 // // The ACQT aquisition time should take into accound the internal aquisition // time TACQ of the ADC, datasheet paramter 130, and the settling time of // of the application circuit connected to the ADC pin. Since the actual // settling time of the RC circuit with the demo board potentiometer is very // long but accuracy is not very important to this demo, we'll set ACQT2-0 to // 20TAD = 111 // // ADFM = 0 so we can easily read the 8 Most Significant bits from the ADRESH // Special Function Register ADCON2 = 0b00111000; // Select channel 0 (AN0) to read the potentiometer voltage and turn on ADC ADCON0 = 0b00000001; } unsigned char ADC_Convert(void) { // start an ADC conversion and return the 8 most-significant bits of the result ADCON0bits.GO_DONE = 1; // start conversion while (ADCON0bits.GO_DONE == 1); // wait for it to complete return ADRESH; // return high byte of result }