// STC 官網 STC12C5Axx Series MCU A/D 例程
#include "reg51.h"
#include "intrins.h"
#define FOSC 11059200L
#define BAUD 9600
typedef unsigned char BYTE;
typedef unsigned int WORD;
/*Declare SFR associated with the ADC */
sfr ADC_CONTR = 0xBC; //ADC control register
sfr ADC_RES = 0xBD; //ADC high 8-bit result register
sfr ADC_LOW2 = 0xBE; //ADC low 2-bit result register
sfr P1ASF = 0x9D; //P1 secondary function control register
/*Define ADC operation const for ADC_CONTR*/
#define ADC_POWER 0x80 //ADC power control bit
#define ADC_FLAG 0x10 //ADC complete flag
#define ADC_START 0x08 //ADC start control bit
#define ADC_SPEEDLL 0x00 //420 clocks
#define ADC_SPEEDL 0x20 //280 clocks
#define ADC_SPEEDH 0x40 //140 clocks
#define ADC_SPEEDHH 0x60 //70 clocks
void InitUart();
void InitADC();
void SendData(BYTE dat);
BYTE GetADCResult(BYTE ch);
void Delay(WORD n);
void ShowResult(BYTE ch);
void main()
{
InitUart(); //Init UART, use to show ADC result
InitADC(); //Init ADC sfr
while (1)
{
ShowResult(0); //Show Channel0
ShowResult(1); //Show Channel1
ShowResult(2); //Show Channel2
ShowResult(3); //Show Channel3
ShowResult(4); //Show Channel4
ShowResult(5); //Show Channel5
ShowResult(6); //Show Channel6
ShowResult(7); //Show Channel7
}
}
/*----------------------------
Send ADC result to UART
----------------------------*/
void ShowResult(BYTE ch)
{
SendData(ch); //Show Channel NO.
SendData(GetADCResult(ch)); //Show ADC high 8-bit result
//if you want show 10-bit result, uncomment next line
// SendData(ADC_LOW2); //Show ADC low 2-bit result
}
/*----------------------------
Get ADC result
----------------------------*/
BYTE GetADCResult(BYTE ch)
{
ADC_CONTR = ADC_POWER | ADC_SPEEDLL | ch | ADC_START;
_nop_(); //Must wait before inquiry
_nop_();
_nop_();
_nop_();
while (!(ADC_CONTR & ADC_FLAG));//Wait complete flag
ADC_CONTR &= ~ADC_FLAG; //Close ADC
return ADC_RES; //Return ADC result
}
/*----------------------------
Initial UART
----------------------------*/
void InitUart()
{
SCON = 0x5a; //8 bit data ,no parity bit
TMOD = 0x20; //T1 as 8-bit auto reload
TH1 = TL1 = -(FOSC/12/32/BAUD); //Set Uart baudrate
TR1 = 1; //T1 start running
}
/*----------------------------
Initial ADC sfr
----------------------------*/
void InitADC()
{
P1ASF = 0xff; //Open 8 channels ADC function
ADC_RES = 0; //Clear previous result
ADC_CONTR = ADC_POWER | ADC_SPEEDLL;
Delay(2); //ADC power-on and delay
}
/*----------------------------
Send one byte data to PC
Input: dat (UART data)
Output:-
----------------------------*/
void SendData(BYTE dat)
{
while (!TI); //Wait for the previous data is sent
TI = 0; //Clear TI flag
SBUF = dat; //Send current data
}
/*----------------------------
Software delay function
----------------------------*/
void Delay(WORD n)
{
WORD x;
while (n--)
{
x = 5000;
while (x--);
}
} |
