在嵌入式Qt项目上校准和配置evdevtouch [英] Calibrating and configuring evdevtouch on embedded qt project

问题描述

我有一个在Linux的icoremx6solo上运行的Qt项目。
我已经设置好图形并运行代码，但是我无法处理触摸输入。
使用$ p $

export QT_LOGGING_RULES = qt.qpa.input = true

$ b $启用输入日志记录b

我发现没有设置坐标ar，我认为这是主要的问题：

  qt.qpa.input：evdevtouch：/ dev / input / event0：协议类型B（多）
 qt.qpa.input：evdevtouch：/ dev / input / event0：最小X：0最大X：-1 
 qt.qpa.input：evdevtouch：/ dev / input / event0：最小Y：0最大Y：-1 
 qt.qpa.input：evdevtouch：/ dev / input / event0：最小压力：0最大压力：0 
 qt.qpa.input：evdevtouch：/ dev / input / event0：设备名称：EP0790M09 
  

但我找不到校准该evdevtouch的方法。

我尝试用

那么，如何解决触摸屏正在运行的问题？

解决方案

查看QT的来源（qevdevtouchhandler.cpp），可直接从设备ioctl获得校准值（最小，最大，压力…）。

在Qt中似乎没有办法更改这些值。

看我控制器的内核源代码（Atmel spi上的ADS7843），似乎没有办法从用户空间（/ proc，/ sys）中更改值）。

以下代码片段似乎可以完成工作–读取和写入校准值：

  //检查参数计数
是否（argc！= 3&& argc！= 5）{
 puts（获取用法：evgetset device absnumber）; 
 puts（设置用法：evgetset设备的absnumber值名）； 
返回（1）; 
} 
 
 //第一个参数是设备文件名
 fd = open（argv [1]，O_RDONLY）; 
 if（fd< 0）{
 puts（无法打开设备文件-您是否以root用户身份运行）； 
返回（1）; 
} 
 
 //第二个参数是参数编号
 absnumber = atoi（argv [2]）; 
 if（absnumber< 0 || absnumber> ABS_MAX）{
 puts（ absnumber超出范围）; 
返回（1）; 
} 
 
 //读取ioctl并显示当前值
 ioctl（fd，EVIOCGABS（absnumber），& absval）; 
 printf（％d\n的属性，绝对编号）； 
 printf（ Value：％d\n，absval.value）; 
 printf（ Minimum：％d\n，absval.minimum）; 
 printf（ Maximum：％d\n，absval.maximum）; 
 printf（ Fuzz：％d\n，absval.fuzz）; 
 printf（ Flat：％d\n，absval.flat）; 
 // printf（ Resolution：％d\n，absval.resolution）; 
 
 //检查是否需要写-并进行
 if（argc == 5）{
 valvalue = atoi（argv [4]）; 
 if（！strcmp（ Value，argv [3]））absval.value = valvalue; 
 if（！strcmp（ Minimum，argv [3]））absval.minimum = valvalue; 
 if（！strcmp（ Maximum，argv [3]））puts（ Got Maximum）; 
 if（！strcmp（ Maximum，argv [3]））absval.maximum = valvalue; 
 if（！strcmp（ Fuzz，argv [3]））absval.fuzz = valvalue; 
 if（！strcmp（ Flat，argv [3]））absval.flat = valvalue; 
 // if（！strcmp（ Resolution，argv [2]）absval.resolution = valvalue; 
 ioctl（fd，EVIOCSABS（absnumber），& absval）; 
} 
 //全部完成
 close（fd）; 
  

I have a Qt project running on a icoremx6solo with linux. I've setted up the graphics and run the code, but i can't handle touch inputs. Enabling the input logging with

export QT_LOGGING_RULES="qt.qpa.input=true"

i discovered that the coordinates ar not setted, i think that this is the main problem with that:

qt.qpa.input: evdevtouch: /dev/input/event0: Protocol type B  (multi)   
qt.qpa.input: evdevtouch: /dev/input/event0: min X: 0 max X: -1
qt.qpa.input: evdevtouch: /dev/input/event0: min Y: 0 max Y: -1
qt.qpa.input: evdevtouch: /dev/input/event0: min pressure: 0 max pressure: 0      
qt.qpa.input: evdevtouch: /dev/input/event0: device name: EP0790M09

but i can't find a way to calibrate that evdevtouch.

I tried runnin the executable with -plugin tslib attribute after executing the ts_calibrate command but the output is the same.

so, how can i fix that having a running touchscreen?

解决方案

Looking at QT's source (qevdevtouchhandler.cpp) the calibration values (min, max, pressure…) are obtained directly from the device ioctl.

There doesn't seem to be a way in Qt to change these values.

Looking at the kernel source for my controller (ADS7843 on Atmel spi) there doesn't seem to a way to change the values from user space (/proc, /sys).

The following snippet seems to do the job – reading and writing the calibration values:

    // check the parameter count
    if (argc != 3 && argc != 5) {
        puts ("Get usage: evgetset device absnumber");
        puts ("Set usage: evgetset device absnumber valname value");
        return (1);
    }

    // the first parameter is the device file name
    fd = open(argv[1], O_RDONLY);
    if (fd < 0) {
            puts ("Could not open device file - are you running as root");
        return (1);
    }

    // the second parameter is the parameter number
    absnumber = atoi (argv[2]);
    if (absnumber < 0 || absnumber > ABS_MAX) {
        puts ("absnumber out of range");
        return (1);
    }

    // Read the ioctl and display the current values
    ioctl(fd, EVIOCGABS(absnumber), &absval);
    printf ("Properties for %d\n", absnumber);
    printf ("Value : %d\n", absval.value);
    printf ("Minimum : %d\n", absval.minimum);
    printf ("Maximum : %d\n", absval.maximum);
    printf ("Fuzz : %d\n", absval.fuzz);
    printf ("Flat : %d\n", absval.flat);
//  printf ("Resolution : %d\n", absval.resolution);

    // check if a write is wanted - and do it
    if (argc == 5) {
        valvalue = atoi (argv[4]);
        if (!strcmp ("Value", argv[3])) absval.value = valvalue;
        if (!strcmp ("Minimum", argv[3])) absval.minimum = valvalue;
        if (!strcmp ("Maximum", argv[3])) puts ("Got Maximum");
        if (!strcmp ("Maximum", argv[3])) absval.maximum = valvalue;
        if (!strcmp ("Fuzz", argv[3])) absval.fuzz = valvalue;
        if (!strcmp ("Flat", argv[3])) absval.flat = valvalue;
//      if (!strcmp ("Resolution", argv[2]) absval.resolution = valvalue;
        ioctl(fd, EVIOCSABS(absnumber), &absval);
    }
    // all done
    close(fd);

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