51 MCU AD conversion program-EEWORLD

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void Read_init (unsigned char CHA){
unsigned char AD_FIN=0; //Store A/D conversion flag
CHA &= 0x07; //Select one of the 8 interfaces of ADC (0000 0111 clears the high 5 bits)
ADC_CONTR = 0x40; //ADC conversion speed (0XX0 0000 where XX controls the speed, please set according to the data sheet)
_nop_();
ADC_CONTR |= CHA; //Select the current A/D channel
_nop_();
ADC_CONTR |= 0x80; //Start A/D power supply
DELAY_MS(1); //Let the input voltage reach stability (1ms is enough)
}
unsigned char Read (void) {
unsigned char AD_FIN=0; //Store A/D conversion flag
ADC_CONTR |= 0x08; //Start A/D conversion (0000 1000 makes ADCS = 1)
_nop_();
_nop_();
_nop_();
_nop_();
while (AD_FIN ==0){ //Wait for A/D conversion to end
AD_FIN = (ADC_CONTR & 0x10); //0001 0000 Test whether A/D conversion is finished
}
ADC_CONTR &= 0xE7; //1111 0111 clear ADC_FLAG bit, turn off A/D conversion,
return (ADC_DATA); //Return A/D conversion result (8 bits)
}

Above - 8-bit ADC program module (applicable to STC12C2052AD series)

C Code

#include //MCU header file
#include //51 basic operations (including _nop_ empty function)
void DELAY_MS (unsigned int a){
unsigned int i;
while( a-- != 0){
for(i = 0; i < 600; i++);
}
}
void UART_init (void) {
//EA = 1; //Enable general interrupts (if interrupts are not used, they can be //masked)
//ES = 1; //Enable UART serial port interrupt
TMOD = 0x20; //Timer T/C1 working mode 2
SCON = 0x50; //Serial port working mode 1, serial port reception is allowed (serial port reception is prohibited when SCON = 0x40 )
TH1 = 0xF3; //Set the high 8 bits of the timer initial value
TL1 = 0xF3; //Set the initial value of the timer to the lower 8 bits
PCON = 0x80; //Baud rate multiplication (shield the baud rate of this sentence to 2400)
TR1 = 1; //Timer starts
}
void UART_T (unsigned char UART_data){ //Define the serial port sending data variable
SBUF = UART_data; //Send the received data back
while(TI == 0); //Check the send interrupt flag
TI = 0; //Set the transmit interrupt flag to 0 (cleared by software)
}
void Read_init (unsigned char CHA){
unsigned char AD_FIN=0; //Store A/D conversion flag
CHA &= 0x07; //Select one of the 8 interfaces of ADC (0000 0111 clears the high 5 bits)
ADC_CONTR = 0x40; //ADC conversion speed (0XX0 0000 where XX controls the speed, please set according to the data sheet)
_nop_();
ADC_CONTR |= CHA; //Select the current A/D channel
_nop_();
ADC_CONTR |= 0x80; //Start A/D power supply
DELAY_MS(1); //Let the input voltage reach stability (1ms is enough)
}
unsigned char Read (void) {
unsigned char AD_FIN=0; //Store A/D conversion flag
ADC_CONTR |= 0x08; //Start A/D conversion (0000 1000 makes ADCS = 1)
_nop_();
_nop_();
_nop_();
_nop_();
while (AD_FIN ==0){ //Wait for A/D conversion to end
AD_FIN = (ADC_CONTR & 0x10); //0001 0000 Test whether A/D conversion is finished
}
ADC_CONTR &= 0xE7; //1111 0111 clear ADC_FLAG bit, turn off A/D conversion,
return (ADC_DATA); //Return A/D conversion result (8 bits)
}
void main (void) {
unsigned char R;
UART_init(); //Serial port initialization program
Read_init(0); //ADC initialization
P1M0 = 0x01; //P1.7~.0: 0000 0001 (high impedance) //Note: When changing the ADC channel, the corresponding IO interface must be changed to high impedance input at the same time.
P1M1 = 0x00; //P1.7~.0: 0000 0000 (forced push)
while(1){
R = Read ();
UART_T (R); //Serial port secretary, send ADC reading value to serial port for display
}
}

Above - 8-bit ADC application example (applicable to STC12C2052AD series)

C Code

void Read_init (unsigned char CHA){
unsigned char AD_FIN=0; //Store A/D conversion flag
CHA &= 0x07; //Select one of the 8 interfaces of ADC (0000 0111 clears the high 5 bits)
ADC_CONTR = 0x40; //ADC conversion speed (0XX0 0000 where XX controls the speed, please set according to the data sheet)
_nop_();
ADC_CONTR |= CHA; //Select the current A/D channel
_nop_();
ADC_CONTR |= 0x80; //Start A/D power supply
DELAY_MS(1); //Let the input voltage reach stability (1ms is enough)
}
unsigned int ADC_Read (void) {
unsigned char AD_FIN=0; //Store A/D conversion flag
ADC_CONTR |= 0x08; //Start A/D conversion (0000 1000 makes ADCS = 1)
_nop_();
_nop_();
_nop_();
_nop_();
while (AD_FIN ==0){ //Wait for A/D conversion to end
AD_FIN = (ADC_CONTR & 0x10); //0001 0000 Test whether A/D conversion is finished
}
ADC_CONTR &= 0xE7; //1111 0111 clear ADC_FLAG bit, turn off A/D conversion,
return (ADC_RES*4+ADC_RESL); //Return the A/D conversion result (the high 8 bits of the 10-bit ADC data are in ADC_RES, and the low 2 bits are in ADC_RESL)
}

Above - 10-bit ADC program module (for STC12C5A60S2 series)

C Code

#include //MCU header file
#include //51 basic operations (including _nop_ empty function)
void DELAY_MS (unsigned int a){
unsigned int i;
while( a-- != 0){
for(i = 0; i < 600; i++);
}
}
void UART_init (void) {
//EA = 1; //Enable general interrupts (if interrupts are not used, they can be //masked)
//ES = 1; //Enable UART serial port interrupt
TMOD = 0x20; //Timer T/C1 working mode 2
SCON = 0x50; //Serial port working mode 1, serial port reception is allowed (serial port reception is prohibited when SCON = 0x40 )
TH1 = 0xF3; //Set the high 8 bits of the timer initial value
TL1 = 0xF3; //Set the initial value of the timer to the lower 8 bits
PCON = 0x80; //Baud rate multiplication (shield the baud rate of this sentence to 2400)
TR1 = 1; //Timer starts
}
void UART_T (unsigned char UART_data){ //Define the serial port sending data variable
SBUF = UART_data; //Send the received data back
while(TI == 0); //Check the send interrupt flag
TI = 0; //Set the transmit interrupt flag to 0 (cleared by software)
}
void Read_init (unsigned char CHA){
unsigned char AD_FIN=0; //Store A/D conversion flag
CHA &= 0x07; //Select one of the 8 interfaces of ADC (0000 0111 clears the high 5 bits)
ADC_CONTR = 0x40; //ADC conversion speed (0XX0 0000 where XX controls the speed, please set according to the data sheet)
_nop_();
ADC_CONTR |= CHA; //Select the current A/D channel
_nop_();
ADC_CONTR |= 0x80; //Start A/D power supply
DELAY_MS(1); //Let the input voltage reach stability (1ms is enough)
}
void ADC_Read (void) {
unsigned char AD_FIN=0; //Store A/D conversion flag
ADC_CONTR |= 0x08; //Start A/D conversion (0000 1000 makes ADCS = 1)
_nop_();
_nop_();
_nop_();
_nop_();
while (AD_FIN ==0){ //Wait for A/D conversion to end
AD_FIN = (ADC_CONTR & 0x10); //0001 0000 Test whether A/D conversion is finished
}
ADC_CONTR &= 0xE7; //1111 0111 clear ADC_FLAG bit, turn off A/D conversion,
}
void main (void) {
UART_init(); //Serial port initialization program
Read_init(0); //ADC initialization
P1M1 = 0x01; //P1.7~P1.0: 0000 0001 (high impedance) //Note: When changing the ADC channel, the corresponding IO interface must be changed to high impedance input at the same time.
P1M0 = 0x00; //P1.7~P1.0: 0000 0000 (forced)
while(1){
ADC_Read (); //Call ADC conversion program
UART_T (ADC_RES); //Serial port secretary, send the high 8 bits of the ADC read value to the serial port 0000 0000
UART_T (ADC_RESL); //Serial port secretary, send the lower 2 bits of the ADC read value to the serial port XXXX XX00
}
}

Reference address：51 MCU AD conversion program

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