读取x，y数据总是255，正常应该为x=0,y=255; or x=255,y=0.查了好久没有发现问题。
程序如下:
#include <REG51.h>
#include "intrins.h"
typedef unsigned char UINT8;
typedef unsigned int UINT16;
typedef unsigned long UINT32;
/*Address Byte
1 0 0 1 0 A1 A0 R/W
|_____________| |_____|
fixed bits input pins read"1"/write"0"
*/
#define TSC2003_WRITE 0x90 //1001 0000
#define TSC2003_READ 0x91 //1001 0001
/*Command Byte
C3 C2 C1 C0 PD1 PD0 M X
|_____________| |______|
Configuration bits power_down bits mode bit reserved
*/
//1011 0000 reserved
#define COMMAND_X 0xc0 //1100 0000
#define COMMAND_Y 0xd0 //1101 0000
#define COMMAND_Z1 0xe0 //1110 0000
#define COMMAND_Z2 0xf0 //1111 0000
#define I2C_DELAY 2
unsigned char data touch_x,touch_y;
sbit SDIO = P1^6;
sbit SCLK = P1^7;
void ShortDelay(unsigned char time)
{
while(--time);
}
void i2c_start(void)
{
SDIO = 1;
SCLK = 1;
ShortDelay(I2C_DELAY);
SDIO = 0;
ShortDelay(I2C_DELAY);
SCLK = 0;
ShortDelay(I2C_DELAY);
}
void i2c_stop(void)
{
SCLK = 0;
ShortDelay(I2C_DELAY);
SDIO = 0;
ShortDelay(I2C_DELAY);
SCLK = 1;
ShortDelay(I2C_DELAY);
SDIO = 1;
}
UINT8 i2c_byte_wr(UINT8 dat) /* return 0 --> ack */
{
UINT8 i;
UINT8 temp_value = 0;
for(i=8; i!=0; i--)
{
SCLK = 0;
ShortDelay(I2C_DELAY);
SDIO = (bit)(dat & 0x80);
ShortDelay(I2C_DELAY);
dat <<= 1;
SCLK = 1;
ShortDelay(I2C_DELAY);
}
SCLK = 0;
ShortDelay(I2C_DELAY);
SDIO = 1;
ShortDelay(I2C_DELAY);
SCLK = 1;
ShortDelay(I2C_DELAY);
temp_value = SDIO;
return temp_value;
}
UINT8 i2c_byte_rd(UINT8 ack)
{
UINT8 i, temp_value;
SDIO = 1;
temp_value = 0;
ShortDelay(I2C_DELAY);
for(i=8; i!=0; i--)
{
SCLK = 0;
ShortDelay(I2C_DELAY);
SCLK = 1;
ShortDelay(I2C_DELAY);
temp_value <<= 1;
if(SDIO) temp_value++;
ShortDelay(I2C_DELAY);
}
SCLK = 0;
ShortDelay(I2C_DELAY);
SDIO = ack;
ShortDelay(I2C_DELAY);
SCLK = 1;
ShortDelay(I2C_DELAY);
SCLK = 0;
return temp_value;
}
void write_tsc2003(unsigned char address,unsigned char command)
{
i2c_start();
i2c_byte_wr(address);
i2c_byte_wr(command);
i2c_stop();
}
unsigned int read_tsc2003(unsigned char address)
{
unsigned int retValue;
i2c_start();
i2c_byte_wr(address);
retValue = i2c_byte_rd(0)*0x100+i2c_byte_rd(1);
i2c_stop();
retValue>>=4;
return (retValue);
}
void delay_30ms(void)
{
unsigned int i;
#ifdef CLOCK6
for(i = 0; i < 20000; i ++);
#else
for(i = 0; i < 10000; i ++);
#endif
}
void main(void)
{
IE = 0;
IP = 0;
// init all I/Os
P0 = 0xff;
P1 = 0xff;
P2 = 0xff;
P3 = 0xff;
delay_30ms();
delay_30ms();
for(;;)
{
write_tsc2003(TSC2003_WRITE,COMMAND_X); //用差分方式读X坐标
touch_x = read_tsc2003(TSC2003_READ)>>4; //读X轴坐标地址命令,只取8位数据
write_tsc2003(TSC2003_WRITE,COMMAND_Y); //用差分方式读Y坐标
touch_y = read_tsc2003(TSC2003_READ)>>4; //读Y轴坐标地址命令,只取8位数据
P0 = touch_x; //接8个LED
P2 = touch_y; //接8个LED
delay_30ms();
}
} |
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