基于
@littleshrimp 的HID帖子实现的，最近一直查看相关资料，总算整明白了。基于SensorTile实现了无线触摸屏，目前自动从左上角点击滑动到右下角。
1. 目前实现的是单点触摸，后续会实现多点触摸；
2. 参考文档比较多，@littleshrimp 版主的 空中飞鼠 帖子，微软的描述符文章，Android文章https://source.android.com/devices/input/touch-devices
最终实现了，不容易，真不容易。先发一个图得瑟一下，后续再整理详细的文章，我对Android底层开发熟悉一些，有相关问题可以咨询的。
个人技术博客：https://blog.csdn.net/kangear
补充：
HID => linux kernel input子系统 => Android input子系统
就单点触控而言，倒着看Android里对触摸屏的要求，如下图所示：上报键ABS_X 和 ABS_Y以及BTN_TOUCH，另外还需要一个配置文件指定该设备类型为触摸屏。
(一个设备上传了哪些键值可以通过adb shell getevent -i查看)
对应到Linux内核（以3.4内核为准）里，HID的描述符就需要包含User Page为DIGITIZER，包含TIPSWITCH
这里的这个描述符稍微精简一下就可以了。最终如下：
- 0x05, 0x0d, // USAGE_PAGE (Digitizers)
- 0x09, 0x04, // USAGE (Touch Screen)
- 0xa1, 0x01, // COLLECTION (Application)
- 0x85, 0x01, // REPORT_ID (Touch) (REPORTID_TOUCH is 1)
- 0x09, 0x20, // USAGE (Stylus)
- 0xa1, 0x00, // COLLECTION (Physical)
- 0x09, 0x42, // USAGE (Tip Switch)
- 0x15, 0x00, // LOGICAL_MINIMUM (0)
- 0x25, 0x01, // LOGICAL_MAXIMUM (1)
- 0x75, 0x01, // REPORT_SIZE (1)
- 0x95, 0x01, // REPORT_COUNT (1)
- 0x81, 0x02, // INPUT (Data,Var,Abs)
- 0x95, 0x03, // REPORT_COUNT (3)
- 0x81, 0x03, // INPUT (Cnst,Ary,Abs)
- /*
- 0x09, 0x32, // USAGE (In Range)
- 0x09, 0x47, // USAGE (Confidence)
- 0x95, 0x02, // REPORT_COUNT (2)
- 0x81, 0x02, // INPUT (Data,Var,Abs)
- 0x95, 0x0a, // REPORT_COUNT (10)
- 0x81, 0x03, // INPUT (Cnst,Ary,Abs)
- */
- 0x05, 0x01, // USAGE_PAGE (Generic Desktop)
- 0x26, 0xff, 0x7f, // LOGICAL_MAXIMUM (32767)
- 0x75, 0x10, // REPORT_SIZE (16)
- 0x95, 0x01, // REPORT_COUNT (1)
- 0xa4, // PUSH
- 0x55, 0x0d, // UNIT_EXPONENT (-3)
- 0x65, 0x00, // UNIT (None)
- 0x09, 0x30, // USAGE (X)
- 0x35, 0x00, // PHYSICAL_MINIMUM (0)
- 0x46, 0x00, 0x00, // PHYSICAL_MAXIMUM (0)
- 0x81, 0x02, // INPUT (Data,Var,Abs)
- 0x09, 0x31, // USAGE (Y)
- 0x46, 0x00, 0x00, // PHYSICAL_MAXIMUM (0)
- 0x81, 0x02, // INPUT (Data,Var,Abs)
- 0xb4, // POP
- /*
- 0x05, 0x0d, // USAGE PAGE (Digitizers)
- 0x09, 0x48, // USAGE (Width)
- 0x09, 0x49, // USAGE (Height)
- 0x95, 0x02, // REPORT_COUNT (2)
- 0x81, 0x02, // INPUT (Data,Var,Abs)
- 0x95, 0x01, // REPORT_COUNT (1)
- 0x81, 0x03, // INPUT (Cnst,Ary,Abs)
- */
- 0xc0, // END_COLLECTION
- 0xc0, // END_COLLECTION
然后在while循环里，模拟发出一个触摸滑动的事件
- static int8_t ipRepVal[REPORT_IP_LEN_0] = {0};
-
- /*
- static int8_t cnt = 0;
-
- if(cnt == 0) {
- ipRepVal[1] = MOUSE_OFFSET_X;
- ipRepVal[2] = MOUSE_OFFSET_Y;
- cnt++;
- } else {
- ipRepVal[1] = -MOUSE_OFFSET_X;
- ipRepVal[2] = -MOUSE_OFFSET_Y;
- cnt--;
- }
- */
- ipRepVal[1] = 0x01; // down
- if (abs_hor < 32760) {
- abs_hor += 20;
- abs_ver += 20;
- } else {
- ipRepVal[1] = 0x00; // up
- }
- ipRepVal[0] = 0x01; // Report ID
- ipRepVal[2] = abs_hor%256;
- ipRepVal[3] = abs_hor/256;
- ipRepVal[4] = abs_ver%256;
- ipRepVal[5] = abs_ver/256;
-
- HidDevice_Update_Input_Report(0,0,REPORT_IP_LEN_0,ipRepVal);
- if (ipRepVal[1] == 0x00) {
- abs_hor = 0;
- abs_ver = 0;
- }
Android系统中的放一个配置文件，路径:/system/usr/idc/HID.idc
- # Copyright (C) 2010 The Android Open Source Project
- #
- # Licensed under the Apache License, Version 2.0 (the "License");
- # you may not use this file except in compliance with the License.
- # You may obtain a copy of the License at
- #
- # [url=http://www.apache.org/licenses/LICENSE-2.0]http://www.apache.org/licenses/LICENSE-2.0[/url]
- #
- # Unless required by applicable law or agreed to in writing, software
- # distributed under the License is distributed on an "AS IS" BASIS,
- # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- # See the License for the specific language governing permissions and
- # limitations under the License.
-
- #
- # Input Device Calibration File for the touch screen.
- #
-
- # Basic Parameters
- touch.deviceType = touchScreen
- #touch.orientationAware = 1
-
- # Size
- # Based on empirical measurements, we estimate the size of the contact
- # using size = sqrt(area) * 43 + 0.
- #touch.size.calibration = area
- #touch.size.scale = 6
- #touch.size.bias = 0
- #touch.size.isSummed = 0
-
- # Pressure
- # Driver reports signal strength as pressure.
- #
- # A normal thumb touch typically registers about 80 signal strength
- # units although we don't expect these values to be accurate.
- #touch.pressure.calibration = amplitude
- #touch.pressure.scale = 0.0125
- #
- # Orientation
- #touch.orientation.calibration = none
-
这样连接到该设备后就可以如下图自动从左上角滑动到右下角了。这里有git diff文件可以详细查看：
https://gitee.com/kangear/STM32C ... 59307223735d3658e6d
本帖最后由 kangear 于 2018-7-20 23:04 编辑
本帖最后由 kangear 于 2018-7-26 15:53 编辑
这个算是惊喜。
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