Originál kod od microchip ke kitu co jsem kupoval je tento:
Kód: Vybrat vše
/**
*******************************************************************
* Lesson 12 - "LookupTable"
*
* This shows using a table lookup function to implement a
* binary to gray code conversion. The POT is read by the A2D,
* The high order 4 bits then are converted to Gray Code and
* displayed on the LEDs.
*
* The ADC value is used as the offset into reading the gray code equivalent inside of
* a constant data array.
*
* Gray coded binary will be reflected on the LEDs in accordance with the POT reading
*
* PIC: 18F14K22
* Compiler: XC8 v1.00
* IDE: MPLABX v1.10
*
* Board: PICkit 3 Low Pin Count Demo Board
* Date: 6.1.2012
*
* *******************************************************************
* See Low Pin Count Demo Board User's Guide for Lesson Information*
* ******************************************************************
*/
#include <htc.h> //PIC hardware mapping
#define _XTAL_FREQ 500000 //Used by the compiler for the delay_ms(x) macro
//config bits that are part-specific for the PIC18F14K22
__CONFIG(1, FOSC_IRC & PLLEN_OFF & FCMEN_OFF);
__CONFIG(2, PWRTEN_OFF & BOREN_OFF & WDTEN_OFF);
__CONFIG(3, HFOFST_OFF & MCLRE_OFF);
__CONFIG(4, STVREN_ON & LVP_OFF & DEBUG_ON);
__CONFIG(5, CP0_OFF & CP1_OFF & CPB_OFF & CPD_OFF);
__CONFIG(6, WRT0_OFF & WRT1_OFF & WRTC_OFF & WRTB_OFF & WRTD_OFF);
__CONFIG(7, EBTR0_OFF & EBTR1_OFF & EBTRB_OFF);
unsigned char adc(void); //prototype
//Important to use the 'const' keyword here. This puts the array
//into program space instead of data space. This is ideal for values
//that do not change
// b'0000' : 0
// b'0001' : 1
// ... : ...
const unsigned char gray_code[] = { //lookup table for binary->gray code
0b0000,0b0001,0b0011,0b0010,0b0110,
0b0111,0b0101,0b0100,0b1100,0b1101,
0b1111,0b1110,0b1010,0b1011,0b1001,
0b1000
};
void main(void){
unsigned char adc_value;
OSCCON = 0b00100010; //500KHz clock speed
TRISC = 0; //all LED pins are outputs
TRISAbits.TRISA4 = 1; //Potentiamtor is connected to RA4...set as input
ANSELbits.ANS3 = 1; //analog input - different than pic16 syntax
ADCON0 = 0b00001101; //select RA4 as source of ADC, which is AN3, and enable the module
ADCON2 = 0b00000001; //left justified - FOSC/8 speed
while(1){
adc_value = adc(); //get the ADC value from the POT
adc_value >>= 4; //save only the top 4 MSbs
LATC = gray_code[adc_value]; //convert to Grey Code and display on the LEDs
}
}
unsigned char adc(void) {
__delay_us(5); //wait for ADC charging cap to settle
GO = 1;
while (GO) continue; //wait for conversion to be finished
return ADRESH; //grab the top 8 MSbs
}
Important to use the 'const' keyword here. This puts the array into program space instead of data space. This is ideal for values that do not change.
Tak co myslíte? Je možné, že u atmelu je to jinak než u picu? Bylo by to jednodužší...
Aha tak možná to umístění bude důležité...