2021年09月30日 | S3C2440裸机------触摸屏_利用ADC读取触摸屏坐标

前面我们在按下触摸屏时只是打印调试信息，现在我们再按下的中断处理函数里面增加ADC的配置代码，当我们按下后利用ADC读取触摸屏的坐标。

#include "../s3c2440_soc.h"

#define ADC_INT_BIT (10)

#define TC_INT_BIT  (9)

#define INT_ADC_TC   (31)

/* ADCTSC's bits */

#define WAIT_PEN_DOWN    (0<<8)

#define WAIT_PEN_UP      (1<<8)

#define YM_ENABLE        (1<<7)

#define YM_DISABLE       (0<<7)

#define YP_ENABLE        (0<<6)

#define YP_DISABLE       (1<<6)

#define XM_ENABLE        (1<<5)

#define XM_DISABLE       (0<<5)

#define XP_ENABLE        (0<<4)

#define XP_DISABLE       (1<<4)

#define PULLUP_ENABLE    (0<<3)

#define PULLUP_DISABLE   (1<<3)

#define AUTO_PST         (1<<2)

#define WAIT_INT_MODE    (3)

#define NO_OPR_MODE      (0)

void enter_wait_pen_down_mode(void)

{

ADCTSC = WAIT_PEN_DOWN | PULLUP_ENABLE | YM_ENABLE | YP_DISABLE | XP_DISABLE | XM_DISABLE | WAIT_INT_MODE;

}

void enter_wait_pen_up_mode(void)

{

ADCTSC = WAIT_PEN_UP | PULLUP_ENABLE | YM_ENABLE | YP_DISABLE | XP_DISABLE | XM_DISABLE | WAIT_INT_MODE;

}

void enter_auto_measure_mode(void)

{

ADCTSC = AUTO_PST | NO_OPR_MODE;

}

void Isr_Tc(void)

{

//printf("ADCUPDN = 0x%x, ADCDAT0 = 0x%x, ADCDAT1 = 0x%x, ADCTSC = 0x%xnr", ADCUPDN, ADCDAT0, ADCDAT1, ADCTSC);

if (ADCDAT0 & (1<<15))

{

//printf("pen upnr");

enter_wait_pen_down_mode();

}

else

{

//printf("pen downnr");

/* 进入"自动测量"模式 */

enter_auto_measure_mode();

/* 启动ADC */

ADCCON |= (1<<0);

}

}

void Isr_Adc(void)

{

int x = ADCDAT0;

int y = ADCDAT1;

if (!(x & (1<<15))) /* 如果仍然按下才打印 */

{

x &= 0x3ff;

y &= 0x3ff;

printf("x = %08d, y = %08dnr", x, y);

}

enter_wait_pen_up_mode();

}

void AdcTsIntHandle(int irq)

{

if (SUBSRCPND & (1< Isr_Tc();

if (SUBSRCPND & (1< Isr_Adc();

SUBSRCPND = (1<}

void adc_ts_int_init(void)

{

SUBSRCPND = (1< 

/* 注册中断处理函数 */

register_irq(31, AdcTsIntHandle);

/* 使能中断 */

INTSUBMSK &= ~((1< //INTMSK    &= ~(1<}

void adc_ts_reg_init(void)

{

/* [15] : ECFLG,  1 = End of A/D conversion

* [14] : PRSCEN, 1 = A/D converter prescaler enable

* [13:6]: PRSCVL, adc clk = PCLK / (PRSCVL + 1)

* [5:3] : SEL_MUX, 000 = AIN 0

* [2]   : STDBM

* [0]   : 1 = A/D conversion starts and this bit is cleared after the startup.

*/

ADCCON = (1<<14) | (49<<6) | (0<<3);

/*  按下触摸屏, 延时一会再发出TC中断

*  延时时间 = ADCDLY * 晶振周期 = ADCDLY * 1 / 12000000 = 5ms

*/

ADCDLY = 60000;

}

void touchscreen_init(void)

{

/* 设置触摸屏接口:寄存器 */

adc_ts_reg_init();

printf("ADCUPDN = 0x%x, SUBSRCPND = 0x%x, SRCPND = 0x%xnr", ADCUPDN, SUBSRCPND, SRCPND);

/* 设置中断 */

adc_ts_int_init();

/* 让触摸屏控制器进入"等待中断模式" */

enter_wait_pen_down_mode();

}