STM32F746-Disco试用6－触摸屏

STM32F746-Disco开发板的液晶屏是一个电容触摸屏，灵敏度很高，它支持多点触摸。

这个触摸屏的使用也很方便，在Mbed中，已经为我们定义好了触摸屏类TS_DISCO_F746NG。使用方法是：

1. 先包含头文件，
   #include "TS_DISCO_F746NG.h"
   
   
2. 然后定义触摸屏
   TS_DISCO_F746NG ts;
   
   
3. 定义触摸屏状态变量
   TS_StateTypeDef TS_State;
   
   
4. 初始化触摸屏
   ts.Init
   
   
5. 获取触摸屏状态
   ts.GetState(&TS_State);
   
   
6. 判断触摸屏是否按下
   TS_State.touchDetected
   这个变量同时也代表按下点的数量
   
   
7. 触摸位置座标
   x = TS_State.touchX[idx];
   y = TS_State.touchY[idx];
   
   

下面代码演示了检测触摸的效果：

#include "mbed.h"
#include "TS_DISCO_F746NG.h"
#include "LCD_DISCO_F746NG.h"

LCD_DISCO_F746NG lcd;
TS_DISCO_F746NG ts;

int main()
{
    TS_StateTypeDef TS_State;
    uint16_t x, y;
    uint8_t text[30];
    uint8_t status;
    uint8_t idx;
    uint8_t cleared = 0;
    uint8_t prev_nb_touches = 0;

    lcd.DisplayStringAt(0, LINE(5), (uint8_t *)"TOUCHSCREEN DEMO", CENTER_MODE);
    wait(1);

    status = ts.Init(lcd.GetXSize(), lcd.GetYSize());
    if (status != TS_OK) {
        lcd.Clear(LCD_COLOR_RED);
        lcd.SetBackColor(LCD_COLOR_RED);
        lcd.SetTextColor(LCD_COLOR_WHITE);
        lcd.DisplayStringAt(0, LINE(5), (uint8_t *)"TOUCHSCREEN INIT FAIL", CENTER_MODE);
    } else {
        lcd.Clear(LCD_COLOR_GREEN);
        lcd.SetBackColor(LCD_COLOR_GREEN);
        lcd.SetTextColor(LCD_COLOR_WHITE);
        lcd.DisplayStringAt(0, LINE(5), (uint8_t *)"TOUCHSCREEN INIT OK", CENTER_MODE);
    }

    wait(1);
    lcd.SetFont(&Font12);
    lcd.SetBackColor(LCD_COLOR_BLUE);
    lcd.SetTextColor(LCD_COLOR_WHITE);

    while(1) {

        ts.GetState(&TS_State);
        if (TS_State.touchDetected) {
            // Clear lines corresponding to old touches coordinates
            if (TS_State.touchDetected < prev_nb_touches) {
                for (idx = (TS_State.touchDetected + 1); idx <= 5; idx++) {
                    lcd.ClearStringLine(idx);
                }
            }
            prev_nb_touches = TS_State.touchDetected;

            cleared = 0;

            sprintf((char*)text, "Touches: %d", TS_State.touchDetected);
            lcd.DisplayStringAt(0, LINE(0), (uint8_t *)&text, LEFT_MODE);

            for (idx = 0; idx < TS_State.touchDetected; idx++) {
                x = TS_State.touchX[idx];
                y = TS_State.touchY[idx];
                sprintf((char*)text, "Touch %d: x=%d y=%d ", idx+1, x, y);
                lcd.DisplayStringAt(0, LINE(idx+1), (uint8_t *)&text, LEFT_MODE);
            }

            lcd.DrawPixel(TS_State.touchX[0], TS_State.touchY[0], LCD_COLOR_ORANGE);
        } else {
            if (!cleared) {
                lcd.Clear(LCD_COLOR_BLUE);
                sprintf((char*)text, "Touches: 0");
                lcd.DisplayStringAt(0, LINE(0), (uint8_t *)&text, LEFT_MODE);
                cleared = 1;
            }
        }
    }
}

目前发现这个程序在keil中调试有问题，不能运行，还没有找到原因，但是在Mbed compile中可以正常使用。所以暂时不提供Keil的程序，等解决后在添加。

运行效果：