Neonode触摸传感器模块之I2C鼠标和键盘

引言

触摸传感器模块可用于通过I2C向计算机发送键盘或鼠标输入。Arduino Library示例zForceKeyboardMouse中包含了如何实现这一点的示例。该示例使用官方的Arduino库＜Mouse.h＞和＜Keyboard.h＞与主机系统通信。
zForceKeyboardMouse代码

#include 
#include 
#include 

// IMPORTANT: change "1" to assigned GPIO digital pin for dataReady signal in your setup:
#define DATA_READY 1

long globalMillis = millis();         // global timestamp
const int keyboardBoundary = 750;     // set boundary between mouse and keyboard areas on the x-axis to 75 mm.
const int holdTime = 150;             // sensitivity for mouse "left-click", unit in milli-second

TouchData previousTouch;

void setup()
{
  Keyboard.begin();           // initialize keyboard
  Mouse.begin();              // initialize mouse
  Serial.begin(115200);
  Serial.println("zforce start");
  zforce.Start(DATA_READY);

  Message* msg = nullptr;
  
  zforce.Enable(true);

  msg = zforce.GetMessage();

  do
  {
    msg = zforce.GetMessage();
  } while (msg == nullptr);

  if (msg->type == MessageType::ENABLETYPE)
  {
    Serial.print("Message type is: ");
    Serial.println((int)msg->type);
    Serial.println("Sensor is now enabled and will report touches.");
  }

  zforce.DestroyMessage(msg);
}

void loop()
{
  Message* touch = zforce.GetMessage();

  if (touch != nullptr)
  {
    if (touch->type == MessageType::TOUCHTYPE)
    {
      //Sends reported touch coordinates [x,y] and event data to mouse and keyboard function.
      loopMouse(((TouchMessage*)touch)->touchData[0].x, ((TouchMessage*)touch)->touchData[0].y, ((TouchMessage*)touch)->touchData[0].event);
      loopKeyboard(((TouchMessage*)touch)->touchData[0].x, ((TouchMessage*)touch)->touchData[0].y, ((TouchMessage*)touch)->touchData[0].event);
    }
    zforce.DestroyMessage(touch);
  }
}

void loopMouse(int16_t x , int16_t y, int8_t event)
{
  if (x <= keyboardBoundary) //return if the touch object is outside mouse area
  {
    return;
  }

  switch (event)
  {
    case 0:  // DOWN event
      previousTouch.x =  x;
      previousTouch.y =  y;
      globalMillis = millis();
      Serial.println("Mouse Input - DOWN");
      break;

    case 1: // MOVE event
      if ((millis() - globalMillis) >= holdTime)
      {
        Mouse.move((x - previousTouch.x), (y - previousTouch.y));
        Serial.println("Mouse Input - Moving cursor");
      }
      previousTouch.x = x;
      previousTouch.y = y;
      break;

    case 2: // UP event
      Serial.print("Mouse Input - UP");
      if (millis() - globalMillis < holdTime)  // mouse "left click", sensitivity
      { // can be tuned by changing "holdTime"
        Mouse.click(MOUSE_LEFT);
        Serial.print("(Left-Click)");
      }
      Serial.println("");
      break;

    default:
      break;
  }
}

void loopKeyboard(int16_t x , int16_t y, int8_t event)
{
  if (x > keyboardBoundary) //return if the touch object is outside keyboard area
  {
    return; 
  }

  // Only act on event == DOWN, i.e. when an object has entered the touch area
  if (event == 0)
  {
    //assign Key to the given interval
    if (y < 250)
    {
    Keyboard.print('A'); //Print Key "A"
    Serial.println("Keyboard Input - Button Press 'A'");
    }
    else if (y < 500)
    {
    Keyboard.print('B'); //Print Key "B"
    Serial.println("Keyboard Input - Button Press 'B'");
    }
    else if (y < 750)
    {
    Keyboard.print('C'); //Print Key "C"
    Serial.println("Keyboard Input - Button Press 'C'");
    }
    else if (y < 1000)
    {
    Keyboard.print('D'); //Print Key "D"
    Serial.println("Keyboard Input - Button Press 'D'");
    }
    else
    {
    Keyboard.print('E'); //Print Key "E"
    Serial.println("Keyboard Input - Button Press 'E'");
    }
  }
}

触摸传感器模块可以作为空气中解决方案或任何表面放置，为广泛的用户提供了大量的替代方案。传感器模块例如可以被配置为用作个性化控制面板或混合板。由于可自定义的布局和控件，它可以用于开发，也可以帮助需要自定义工作空间的人。

1说明

zForceKeyboardMouse示例展示了如何将触摸输入转换为鼠标或键盘输入。该示例使基于SAMD微型板（例如Neonode原型板）能够通过HID使用官方Arduino库＜mouse.h＞和＜Keyboard.h＞向主机系统发送按键或鼠标导航。此示例将触摸活动区域划分为一个鼠标垫和一个键盘部分，其中包含5个按钮（a-E）。鼠标部分的工作方式类似于相对鼠标垫，其中光标相对于其先前位置移动。
键盘按钮被编程为在每个相应部分中进行触摸时打印字母A-E。
我们可以通过zForce Arduino库访问传感器模块的触摸数据

int16_t x = ((TouchMessage*)touch)->touchData[0].x;
//Touch
input position x coordinate
int16_t y = ((TouchMessage*)touch)->touchData[0].y;
//Touch
input position y coordinate
int8_t event = ((TouchMessage*)touch)->touchData[0].event;
//Touch input event
state, i.e TouchUp, TouchDown...

触摸式鼠标垫
由于触摸传感器模块被识别为触摸屏数字化仪，因此需要提取触摸输入数据，以便将其转换为鼠标输入。为了将绝对位置输入坐标转换为其相对位置（移动），我们将当前触摸数据位置与先前跟踪的对象位置相减。

Mouse.move((x - previousTouch.x), (y - previousTouch.y));
//"x" and "y" arethe location of the reported touch coordinates "previousTouch.x" and "previousTouch.y" are the location of the previous reported coordinate.

在鼠标部分内“点击”或“点击”后，将执行鼠标左键单击操作。当报告的触摸具有事件数据“UP”时，会触发左键点击动作。在实践中，这意味着最终用户需要“按压”和“释放”他们的手指才能进行触摸。触摸灵敏度可以通过全局变量holdTime进行调整，它就像一个“触摸”所需时间的计时器。

为了使用鼠标垫，我们使用从传感器模块收集的触摸信息：

switch (event)
{
case 0: // DOWN event
previousTouch.x = x;
previousTouch.y = y;
globalMillis = millis();
Serial.println("Mouse Input - DOWN");
break;
case 1: // MOVE event
if ((millis() - globalMillis) >= holdTime)
{
Mouse.move((x - previousTouch.x), (y - previousTouch.y));
Serial.println("Mouse Input - Moving cursor");
}
previousTouch.x = x;
previousTouch.y = y;
break;
case 2: // UP event
Serial.print("Mouse Input - UP");
if (millis() - globalMillis < holdTime) // mouse "left click", sensitivity
{ // can be tuned by changing "holdTime"
Mouse.click(MOUSE_LEFT);
Serial.print("(Left-Click)");
}
Serial.println("");
break;
default: break;
}

空中非接触式触摸调节

对于空中解决方案，我们建议在DOWN事件而不是UP事件上预生成所有“左键点击”或“按键”。通过进行此调整，当最终用户按下手指时（而不是松开手指时）将触发左键单击。这为触摸活动区域提供了更具触觉的响应，是空中解决方案的最佳选择
要在DOWN事件上进行左键点击触发，请考虑以下调整：

switch (event)
{
case 0: // DOWN event
previousTouch.x = x;
previousTouch.y = y;
globalMillis = millis();
Mouse.click(MOUSE_LEFT);
//Left-click on DOWN-event
break;
case 1: // MOVE event
if ((millis() - globalMillis) >= holdTime)
{
Mouse.move((x - previousTouch.x), (y - previousTouch.y));
}
previousTouch.x = x;
previousTouch.y = y;
break;
case 2: // UP event
break;
default: break;
}

触摸处理键盘

键盘按钮将根据触摸对象的位置发送按键。每个按钮都由可变键盘Boundary分割，然后进一步分割以区分每个键。
如果报告的带有DOWN事件的触摸位于键盘边界内，则将执行第二次查找，以评估要打印的键。

if (event == 0) { // DOWN event
//assign Key to the given interval
if (y < 250)
Keyboard.print('A'); //Print Key "A"
else if (y < 500)
Keyboard.print('B'); //Print Key "B"
else if (y < 750)
Keyboard.print('C'); //Print Key "C"
else if (y < 1000)
Keyboard.print('D'); //Print Key "D"
else
Keyboard.print('E'); //Print Key "E"
}